Incredible. You have completely changed the definition of "maker". I never would have assumed a casting like this was even possible at home, your expertise and invention are very impressive.
In these days of CNC automation, it must be so rewarding to create such an intricate piece of art while using your hands and mind. I was also happy to see you change from open toe sandals to bedroom slippers for the pour.
First i thought 'aint no way he got a crucible that big to actually pour that big of a cast.....' Then i saw the Lift-assist apparatus on his foundry and instantly fell of my chair and knew that he wasnt playin no games.. Keep going man!! The creative ways you've teached us on different video's on how to cleanly and easy cast anything is soo impressive!! Keep the content coming!!
Thanks Motorsport. Too funny, and it didn't cost $5B! If you haven't already, take in part 3 of same title. I actually got it right in the subsequent go. Best, Kelly
I was really impressed with your set-up for heating and pouring. Simple and effective. I know it took a lot of pre-planning to get the 'swing-set' set-up to the perfect height. As nice as your yard and neighborhood look, I'm trying to imagine the looks of your neighbors, as you do this disgusting 😊 dirty job, among the business community type people (nose in the air), out there, but you kept it very clean and dignified. I worked in a vacuum cleaner factory for 23 years in Canton, Ohio, and the equipment they had to cast vacuum cleaner bottoms, GM transmission parts, and drill gun housings was mammoth and dirty. As an industrial electrician, I got midnight calls to go to machine shops and the like; and got to work on a machine that finished 10-cylinder intake manifolds for Winters Industries, for the Vipers. By contrast, your simplicity here, is amazing. Keep up the good work. You are both an artist and an engineer. My little brother spent half of his life with tools cleaning up heads and intakes for just about any kind of racing industry. I can't wait to show him your set-up and work. (He hates computers, so I will have to lure him over for a peek.)
Neighbors are ok but I've learned that when someone asks how something works, unless they are technical, they don't really want to know unless it can be explqained in under a minute. I just tell them I make the pattern, pack it in sand, and when I pour the metal it takes the place of the foam, and most of them seem are satisfied with that explanation. -Know your audience.🙂Best, Kelly
Ahhh ok... so some of those imperfections are due to the venting I mentioned. There will be spots here and there that need straight up atmospheric vent sprews to prevent those odd spots here and there. But heck u could get it dialed in then spend the time with a grinder and flap disc, and wire disc to get that polished finished. Cool shit. I was trying to decide if I wanted to try this at home. I used to work in a foundry that molded quite a few aluminum parts. So I learned alot about how the process works. Just didn't know if this was something I could do at home but ur design for the gantry made my mind up lol I'm doing it! Love it!
It's true, but it is very time consuming and difficult to pack bound sand in a fragile polystyrene pattern, and it gets very heavy. I've been able to produce much more difficult internally cored parts with unbound sand. I didn't think the pattern position and molding through as well as I should have. Must try again! Best, Kelly
Great attempt Kelly...I love that you show, "The Good, the bad, and the Ugly" this approach is more helpful to everyone learning that there is more to meets he eye than just pouring the metal...Love your gantry and it is something that I had already done, as even 30 pounds is a bit much from a safety factor for me at 66...look forward to part 3.
What a ride SoloMan! (no disrespect). You were this >------< close. When your team is two people down in a crew that should number three, it's to be expected. You're not called the SoloMan for nothing. Very impressive. I hoped for success but but treasure the hard knocks too. You'll get'em the next time. If it wasn't challenging you not would be in the game. And I'll guess we bystanders may not be standing by as faithfully. We live for the challenges. Even if they are experienced vicariously through others. Thanks for the education & memories. 🎶Signed by the secretary, Harper Valley P.T.A. 🎶 Cheers from So.Ca, USA, 3rd House On the Right
Amazing. Even though it wasn't perfect, the results were better than I ever thought possible in the driveway. I want to do my own. Get a better microphone, and get a steady buddy to shoot the video. More fun than a tripod. Subscribed!
Nice complex project, but the preparation for a large pour is next level. I subscribed because I know there is much I can learn from you just based on 2 videos. Well done sir.
OUT=STANDING First class work on design and execution of your pouring rig too,,,Just wish you had a partner there with you in case something went south inn a big way. - You are too valuable to get hurt. Cant wait to see the machining.
The pouring Tongs worked out Great. Really cool to watch. Too Bad about the part for sure. Good luck on the next one. I look forward to seeing how you do it again.
Maybe a 55 gallon drum cut in half to make it easier to work with? Or a box? Something lengthwise? The big foundries have a big sprue roughly the distance of each runner. Like 4 big sprues with a horizontal part.
I'm retired none machinist, I picked up the machinist hobby 25yrs ago. What i've been working on for the past many years is a model V10. I think mostly becouse I work with engines since I was 10. Lot of the parts involed in my build are cast parts being there is the lest amount of machining. Some part where easy, some not so easy. For help with the not so easy parts I have been following U tube such as your site. And yes you have been most helpful in corecting problems such as in gas venting in lost foam casting. I'm like my dog a Yorkee, once she gets to know a person they regert it, never leves any body alone, thank you for your help, whats your Email so as i may pick your brain, I'll be looking for that forum you talked about.
Have you thought about using a venture style vacuum to transfer the sand from one container to another? It's how we move plastic in the molding industry, sometimes it's as hot as 400F. It might be worth a look.
Sorry but I am happy I get a part three. Firstly, I love your foundry setup, it’s put together so well. I have nowhere near as much experience as you but what about mixing up some sand with, is it sodium silica??? You know, the stuff when exposed to co2 it goes hard? I know orientation of the foam will probably solve the issues. Lastly, do you reuse your sand? If not what the heck do you do with it after a Scraping it up off your driveway? I am thoroughly enjoying every video you come out with, thank you very much for sharing.
I have occasionally used ss bound and even some green sand in difficult places but it can cause as many problems as it solves. In lost foam, when you get it right, it's generally not needed and demolding is just dumping sand. I do reuse sand in fact have for five years now. I have a sieve that sit's on top the flasks and I just shovel it in. It does degrade over time. It's cheap and I should have replaced it before this pour. You should join TheHomeFoundry.org. There are detailed threads on this project, many others, and all of my equipment builds and process development from the last five years. Best, Kelly
That was a really well coordinated process. I'm wondering if loading of the internal ducting with sodium silicate binder sand and a CO2 set of that prior to your sand pour would be a good way to ensure full metal exclusion from the ducts.
Thanks Graham. In rare instances I have tucked a blind hole with bound sand but in general I avoid it because it's easy to damage or distort a foam pattern when packing it. Foam patterns are certainly strong enough to handle their own weight while being vibratory packed, but even so, great care must be taken not to distort them with shifting sand. In this case, if the runners were full of bound sand, the pattern would become quite heavy and I doubt it could handled at that weight without distorting or breaking. The primary culprit of the fail in this video was degraded sand that would not easily flow under vibration. With slightly different positioning, I was successful on my next attempt shown in the follow on video at my channel. Best, Kelly
So u can fix those spots by making a sprew to those ends with like an 1/8 dowel rod to each end. Then ur aluminum could fill to the tip and u won't have that issue
Not so. People confuse venting in conventional open cavity sand casting with lost foam casting. In lost foam casting, gases vent through the entire surface of the permeable pattern coating. Vents dont apply because they are blocked by foam pattern until the pattern evaporates and by then, they are blocked by molten metal and are not a vent. People think they need a vent because they see gas bubbling back through the sprue but that's because of inadequate coating permeability, and poor casting and feedsystem design. The fail in this casting was caused by poor mold packing due to contaminated/old sand that no longer flowed well when vibrated. If you skip to parts 3 & 4 of the same series you will see the proper result. Best, Kelly
A lot of measuring and strategizing to break them into the most managble pieces for indidviual 3 axis machining. Beyond that it's just allowing for shrink by making the apttern 1.3% larger. Best, Kelly
I saw a guy who put a copper bat through the sand, used a torch to help heat the sand a bit to slow the cooling, then ran water through to help with cooling, I don't believe the little bit he did really helped or hurt anything. He was doing sand cast, but I think in a setup more like yours, having a .250" tube , with resistance wire inside, insulated with a fine sand, then coil place about 2"off the wall of the barrel, before the sand, then a .500" tube near the same location, to allow cooling, heat the sand up to about 100°F just before the pour, , then then about a 4-5 gph flow of cold water, I speed up cooling, would this be safe? How hot can the foam safely get without warping, because 100° f is nothing relatively speaking, I could see it helping if it's 10-20°f out, but 70° the difference is nothing.. would the effort in normal conditions be worth it? Id like to cast engine parts, intake manifolds, maybe someday cylinder heads, or possibly small engine engine blocks, or possibly even remake old engines , from late1890's to around 1920's early 1930's stationary engines, oil field engines, maybe a modified design version, made from aluminum instead of iron, as far as the cylinder and block,/ crank case, I'm thinking as large as 6"bore to 8" and 12" stroke, or small as 4" bore 6" stroke, in an opposed twin boxer 4, low rpm work horse, to run a generator, possibly a 600 rpm, 1800 absolute peak RPM, making it a oil/ diesel burner would be nice, inject fuel with a high pressure air blast, working similar to a paint sprayer, atomising the fuel, possibly using a multiple stage compressor with the injector compressor taking in 100-120psi,+ into a 2" bore, 2" -3" stroke then compress the air into the fuel injector, spraying the fuel, using a a tiny piston injection pump, throttled by a secondary piston that removes the fuel by adding volume , reducing the ability to pressurize the fuel, possibly use modified lifters as pistons, using a cam to , the air injection may require higher pressure to operate correctly, using a compressor to store air at 120psi, then be compressed again after a slight cooling time, being compressed into a small storage tank, possibly 300 psi, then enter the injector pump/ compressor. Filling the 2"bore with 300psi, the actual pressure would depend on the. Injector and compression ratio, but can possibly be in the 350-400 range the engine having roughly 24:1 compression , spraying oil, used engine oil used vegetable oil, or diesel , kerosene, being sprayed similar to how a paint sprayer would spray, the added air should greatly atomised the fuel, also use heat plugs, and fuel line heaters, and a injector heater, heating the fuel to 200°f just before injection, allowing a cold air intake, dense as possible, then the hot fuel injected as the cylinder pressure peaks,. Possibly use semi truck wheel bearings as crank main bearings, use two 24" flywheels, weighing around 60-80 lbs each use a hub to bolt on to the crank with the flywheel, with a 1.5"& 1" shaft, to drive an alternator, and fan, whatever maybe needed accessories wise, with a 2" and 3" for the serious business end, and make them interchangeable.. use a SBC water pump, to bolt to the water jacket, to circulate water from both banks, both cylinders being the same, the other can be blocked off, making a Rh and Lh engine, making a crank change, and adding a cylinder pair, could be all required to go from 2cylinder to 4cylinder , or 8cylinder, I think this would be about it, use 6-8 v per cylinder with overhead cam , use say 3x 2.125" intake valves, and 3x 1.880" exhaust valves,, the spring pressure could not need to be too great, being rpm is low, possibly in the 20-30 psi seat, and 50-60 on the nose, at most, with roughly .500" lift maybe .750" use 3 1.5" exhaust into a single 2.5" per cylinder, with high port intake and exhaust, the intake uses 2" per valve split from a 4" tube, with a cone filter, with an emergency flap inside, Incase of runaways, maybe use a governor activated release, to close off air , if it reaches 2000rpm, use a governor to maintain a steady 800-900 or 1200 rpm, if I had access to a mill and lathe, and help casting the parts find old diesel engine pistons to cast new from, possibly using a heated mold and press to cast the pistons, possibly cast steel cylinder liners if a steep tube can't be found to make them from, bolt on the water jacket like a motorcycle cylinder, then the water jacket use a o-ring seal, the cylinder liners using a steel o-ring and copper gasket, possibly using a aluminum crush ring with two rings on the jacket one on the head, Sorry to ramble, the insomnia has me up late, I want this engine , to generate power, I'm hoping the 2cyl version would make atleast 150-200 ftlbs TQ. And 40-50 HP, to near 300 TQ, and near 100hp at 1800rpm probably with a bit of boost a small superchargers, I'd probably start with a 4" bore version, with 4.5" maybe 6" stroke use 4valves / cylinder, use a more traditional injection, with a heated injector spinning at upwards of 2400rpm, it would be a better starting points, , sorry to ramble again insomnia is horrible..have a awesome day!!
Hobby stuff so I didn't keep track of time. When it's fun who counts? When it's money.....different story. There was a lot of equipment upgrades I did along the way to mold and pour a part this size that won't recur. I spent a lot of time engineering/designing the part and features versus making the pattern and foundry work. With all that behind me, and now that I'm using a CNC router to make foam patterns, the next one would/will be a small fraction of invested time. Best, Kelly
II really enjoy your blog and have tried 3 times to join the forum but have been unsuccessful. I followed the instructions but must be doing something wrong. Thanks, Joe
Here's the link on how to join the forum. You need to click the contact button at the bottom of the page. If you still have difficulty, let me know. Best, K forums.thehomefoundry.org/index.php?threads/joining-the-forum.1999/
The molten metal evaporates the foam pattern while in place in the mold. The foam undergoes two phase changes; solid to liquid, liquid to gas/vapor. The latter is closest to the molten metal front and passes through the permeable pattern coating into the sand mold and as it does so, it alows the molten metal front to advance consuming all the foam while the metal pressure holds the loose unbound sand in place. Best, Kelly
It depends. If it is a small joint where the glue can be applied and the parts joined in 10-15 seconds, I use low melting point hot melt glue. If it requires long working time, High Tack Poly Vinyl Acetate (white) glue. Laminating is a longer discussion. I have another video on lost foam materials with more discussion. Search my channel. Best, Kelly
On the topic of using vibration to pack the sand around the molds, I wonder about using air injection to induce liquefaction of the sand and allow it to flow around the molds.
There was a similar question asked in another video. Here's my reply: Fluidizing the bed is fine for removing the casting from the packed mold or possibly placing a pattern in a filled flask but it's the opposite of what you want to do a tightly pack a mold. Vibration makes the mold media act like a solid. Fluidization makes it act like....well, a fluid. When you turn the fluidizing air stream off, the sand isn't packed but more akin to having just poured it into the flask so it would still need to be vibrated to have good mold stability and integrity. I had a fluidizing coil in the bottom of my old molding rig. I never used it because I still needed to sift all the sand between uses to remove any loose refractory coating or clumps resulting from the byproducts of the decomposed foam. To filter the sand, I just cut the bottom out of a bucket and replaced the bottom with a perforated plate/screen, place it on top of the storage bucket, and shovel the used sand through it. I also found that with hand placing and filling the pattern and mold, I was better able to avoid pattern damage and deflection than trying to place in a fluidized mold. Best, Kelly
@@kellycoffield533 fascinating. I figured, given the apparent maturity of your equipment, that you’d considered it and had a reason it wasn’t useful. The videos are excellent, keep them up. Personally, I’d find it pretty cool to just watch a timelapse of the foam work that goes into an intake. Wouldn’t even need to narrate it.
Bummer indeed! Oh how the elation of first breakout view turns to major disappointment at failure on closer inspection - we have all been there and as you say modify approach and try again. Love the pouring set up, it looks to be a great success and surprisingly easy to use as it gives you more control over the pour than most crane type crucible lifts - well done - its a good model for others contemplating having to use a crane because of pour weight. I note the suggestion of the use of something like CO2 as a possible solution and I also note your reply as to the problems therein. Even so I think it worth following up on a little as CO2 sand is fairly easy to pack and perhaps a sand based on Fenotec or similar binders may be suitable as it is even easier to pack and may do so with vibration? If so use fenotec sand in place of your current loose sand?? Apparently the set time of fenotec can be varied for 1 minute to 3 hours so plenty of time for pattern immersion and vibration of and into place before set but once set I doubt any leakage will occur. However your comment about weight is noted! Perhaps a thicker coat on the insides of the pattern? Sadly you are a bit on your own here - you are the expert on this process and the best the rest of us can do is guess .😊.Martin
Further to my comment above. I notice that the sand tank is pivot-able, could you perhaps extend this idea to a sort of gimbal arrangement so the tank sand mould assembly could be moved through various angles in all directions as the vibration occurs. Obviously some sort of temporary lid would need to be on the sand to stop it falling out when the angles get steep enough to ensure proper pattern sand contact... Just another stupid idea 😏... Martin
@@olfoundryman8418 Thanks for those thoughts Martin, always much appreciated. You know I will not give up easily. I do occasionally (modestly) tilt the flask when filling/vibrating in an attempt to pack difficult features. You have to be careful because what usually happens is the media in the top of the mold/flask moves to one side and the bottom remains fixed and it the uneven sand pressure can distort the foam pattern, sometimes severely. It's far better to position the pattern wisely and maintain the sand depth in the flask on all pattern surfaces as you pack/fill the flask. That way the sand pressure remains the same on both sides of the wall of any pattern feature. The commercial LF foundries change the direction of vibratory excitation to move and pack the sand in different directions. The turbine vibrators on my molding rig are positionable for that reason. I've successfully molded and stabilized what at least to me seem to be much more difficult cavities than these runners. You probably haven't had an opportunity to read my failure analysis and proposed corrections at The Home Foundry forum thread on this project, but I will have new mold media, pattern positioning, vibratory packing technique, and make a feed system/gating change. for round 2. When you know what doesn't work, it's easily to postulate why, but don't think I don't do my share of guessing too. ;-) Best, Kelly
@@kellycoffield533 Well, that's what I get for sticking my neck out in an area that I don't know much about 😊. But to risk making a fool out of myself yet again a further thought did come to mind. I was some time ago given some resin core sand based on not sand but rather one of the newer ceramic bead molding materials. These beads were about #50 mesh and surprisingly spherical. If you could get the beads (without the shell resin coating) and use this material as your mould media I wonder if their spherical shape might lead to better packing? Or have you already thought of this?... Martin
@@olfoundryman8418 Nothing foolish there Martin. What's foolish is someone pouring a bunch of molten metal on a complex foam pattern without thinking it through....and then pledging to do it again....like some people I know. :-) The LF equipment manufactures ferrous media offerings are typically rounded media, usually mullite/alumina or zirconia based. In a previous life, I did extensive work with filtration using packed media columns. I learned a lot. Round media definitely can be made to flow more easily with vibration than granular media. I think it can be dislodged more easily too but the commercial operations also use vacuum assist and the pressure differential provides additional mold stabilization. If you can sufficiently vibe granular media it lodges together and forms mechanical interference, almost like a bond. The least expensive source of spherical media in low volume is blasting media, and can be bought in any mesh size, but it is about $1USD/pound. I buy my sand at retail stores because it's convenient. It is sieved to size, washed, and dried, and even at retail levels is about 8 cents/lb. If I was willing to buy it in bulk at 1 ton or more it would be 1 or 2 cents/lb. I cant store a ton of sand. I'm still just a guy casting metal in his driveway with equipment I roll out of my shop. Best, Kelly
Kelly , Again I find myself "preaching to the converted" As I should have realized with the effort and thought that you have put in to make the LF process your own you would have investigated the various media options. It seems that CB media is available ex China at about $400.00 per ton. there must be someone importing it (or even making it) in the US. Even allowing a fair mark up it should be available in a suitable quantity that considering its reuse-ability would not be too unreasonable - if it solves a problem. Perhaps I am wrong (again) but as stated above I was given a 25 Kg bag of CB resin coated to try. I was hardly a big customer so for them to just give me the 25 Kg indicated to me that while it was no doubt dearer that the approx $7.50 I pay for 25 Kg of resin coated silica sand it was not that expensive?? (Wrong again ?😏) "Like some people I know" - Hmm, yes there is a lot of that on YT. I just watched an admittedly entertaining video on making a casting and as usual it was full of errors from pattern making to casting finishing. I nearly choked when the offer was made to describe the functions of the various bumps etc in the running system in a future video, if the demand was there - clearly the video-er had no clue as to proper gating etc. In another video a gate was cut in a circular way encompassing about 1/4 of a circle from the sprue (massive parallel) base to the casting - it was explained that this curved gate "cleaned the metal" (groan!) And this from a well known YTer of US origin, he has 20 times my sub level - Sigh - its just not fair. Keep up the good work. I await the next try... Martin
Play sand will work as long as it is dry, and it often is not. If you already have some you want to use, spread it thin on your driveway in the sun and then gather it. It can also be pretty course with small pebbles, which probably doesn't matter much if you are coating your patterns. If you are going to buy, I use "Quikrete" fine sand because it is washed and dried and pretty consistent size. It is typically available at the big box stores in the section that has concrete and mortar mixes. It's probably about 50 mesh and is inexpensive at about $4/50lb bag. The #1 factor for your LF sand is to keep it very dry, else it is hard to excite and pack with vibration. I also store it in sealed buckets for this reason and because it stinks after use. If you are doing iron LF, you'll probably need higher refractory media than silica sand, like aluminum oxide or zirconia. Best, Kelly
The foam is so light you would need a very precise scale, and even so, the density varies enough to make it very unrliable (ask me how I know!). Best is to submerge in water and measure displacement or roughly calculate volume of the part in pieces if necessary. Best, Kelly
U don't have issues with the foam turning into Slag or creating bubbles in ur final part? Just curious how that's prevented. I know in factories they have angles that the part sits as well as correctly placed screw vents at the top of the mold that go to the air and prevent air bubbles in the part. But it looks like u may have solved that by having the part with the right curves and angles pointing the correct direction to prevent bubbles. Idk... waiting to see ur finished part
The fail in this casting was caused by poor mold packing due to contaminated/old sand that no longer flowed well when vibrated. If you skip to parts 3 & 4 of the same series you will see the proper result. You wont have bubbles and entrained gas flaws if your coating is sufficiently permeable, have proper casting and feed systems design, and mold prep. Best, Kelly
Hi Kelly, Very informative video.. I am facing sand sticking issue to final product.. Can you tell me What's the exact issue in the product.. Is it because of to much binding agent. Or less surfactant
When you say "facing sand", that sounds like you are using bound (green or other) sand. In lost foam casting, a refractory coating is applied to the foam pattern and then it is vibratory packed in dry sand. The coating prevents the sand from sticking or imbedding in the casting and essentially reproduces the surface finish of the foam pattern. Though some people do try to use bound sand in lost foam casting, it really defeats one of the benefits of the LF process. Best, Kelly
Can't answer a question like that in a YT reply but if you join www.TheHomeFoundry.com and search user name Al2O3, there are links in my signature to the furnaces. Best, Kelly
Possibly with a bound sand but the foam pattern is probably too weak to being packed and handled with the weight of the sand. It's not necessary. If you view part 3 you'll see the corrections made to successfully cast the part. Best, Kelly
Rig looks great Kelly! That's a whale of a crucible. I'm not competent to comment on your fine work but I will for my ego. The defects you have are hard for someone who does not lost foam cast to understand. It is where the sand did not get packed around the pattern sufficiently and the refractory coating does not hold the metal in. That's why Kelly refers to it a a leaker. Very frustrating to have happen, and it seems so obvious after the pour. Kelly: Have you tried to pre-pack difficult areas? I've thought about filling with sand with a foil tape cover to hold the sand in place during handling. Don't know whether it would work because I haven't tried it. In my experience the density of the packing is not critical so long as there is not an unfilled area. For me, the vibration is just to get the sand to flow, not necessarily to pack it. I'm looking forward to your second pour for the money. Do you see any pattern changes you want to make now that you have a casting?
Pre-packing certainly can work, but for this part, packing the runners would make it too heavy to handle the polystyrene pattern. Vibrating actually does increase the packing density (10-15% typically) and causes the particles to settle into a more tightly/pseudo bound state. Try pulling an object out of a barrel that has just had sand poured around/on it versus vibrated in place and the enhanced packing will be quite apparent. I was asleep at the switch when it came to molding the part. I'm going to have another go with a different pattern position, fresh mold media, and staged vibrating while filling. Best, Kelly
@@kellycoffield533 I hadn't thought about the weight of such a large pattern. Good point! I vibrate my sand and know it packs it in tightly. I'm not certain that is of much value in keeping the metal in the refractory however. Have you had failures due to lightly packed patterns? I've not, on simple patterns where I didn't need the sand to flow.
Owens Corning Foamular 150 Extruded Polystyrene insulation board. If you search my channel for this title "Pattern Materials for Lost Foam Casting" there is more information about materials. Best, Kelly
Yes. It's vibrated in place which tightly packs it without binders. It's perhaps the most attractive feature of lost foam casting.....no cores or worries about parting lines and draft. Best, Kelly
@@kellycoffield533 Thank you for your reply . I saw in you other videos you made ,.you dipped the foam in some sort of slurry! So when that hardens , that will be the outside of the mold which will keep back tue sand once you poor in molten aluminum.
@@kellycoffield533 If you don't mind me asking you one other question about the fioam. So when you poor the aluminum inside the mould, what happens with the foam, does it get burned away . Also I was quite surprised when i didn't see vent holes. Thanks ..
@@Ray88G As the molten metal consumes the pattern, the portion in contact with the pattern is melted/liquid polystyrene and the portion in the liquid PS and the molten metal is gas/evaporated PS. The refractory coating on the pattern is permeable and although some liquid can pass, it is mostly in the form of gas. This is why there are no vents because the entire surface of the pattern vents gas as the metal advances. Best, Kelly
@@Ray88G Yes, but it's really not a structural part of the mold and serves as a permeable coating (as described in the reply above) that also improves surface finish of the casting. Best, Kelly
Before I retired, my place of employment tried to develop the styrofoam evaporative casting process to an industrial level. Years of experimentation and process development went no where. I'm sure other companies do it and do it well, but we were cast iron. Now cast iron is an almost dead material. Too heavy, to much CO2 exhaust.
Here in the US, Lost foam hasn't gained much commercial traction. Sadly, most of the research, process development, related process equipment manufcatures, and commercial practitioners reside in China and most foundry use is in fact for iron castings. There are a few US foundries using lost foam. Mercury Marine in FonduLac Wisconsin for example. Best, Kelly
Maybe you could add a door or two at the bottom of your rig and just open the doors and turn on the vibration to empty the sand rather than dumping it out of the top.
That's not a bad idea. I have a vacuum plenum in the bottom of the existing flask. I did discover that I could controllably tilt and dump the full & fully extended flask so no more trying to knock off th etop extension before the dump. Best, Kelly
Would you possibly be interested in a side project? Im in the process of building a foam intake manifold "much less detailed than yours" for my Cobra R clone...... basically a 2000 Cobra R intake lid, i already have the lower intake i just need to make the upper "hat" part..... let me know if its something your interested in, i understand this wouldnt be cheap
There all side projects ;-). Post your contact info or contact me through my website www.inlinecarb.com. Send a picture and description of what you are looking to do. Best, K
Incredible. You have completely changed the definition of "maker". I never would have assumed a casting like this was even possible at home, your expertise and invention are very impressive.
In these days of CNC automation, it must be so rewarding to create such an intricate piece of art while using your hands and mind. I was also happy to see you change from open toe sandals to bedroom slippers for the pour.
First i thought 'aint no way he got a crucible that big to actually pour that big of a cast.....' Then i saw the Lift-assist apparatus on his foundry and instantly fell of my chair and knew that he wasnt playin no games.. Keep going man!! The creative ways you've teached us on different video's on how to cleanly and easy cast anything is soo impressive!! Keep the content coming!!
Very kind of you to say Woodzey. Glad you enjoy the videos. Best, Kelly
That was better then watching Jeff bezos fly to space. Props on that build. Your a master !
Thanks Motorsport. Too funny, and it didn't cost $5B! If you haven't already, take in part 3 of same title. I actually got it right in the subsequent go. Best, Kelly
Thanks for the videos Kelly. I really appreciate the time you have taken to film them. Cheers old mate.
I was really impressed with your set-up for heating and pouring. Simple and effective. I know it took a lot of pre-planning to get the 'swing-set' set-up to the perfect height. As nice as your yard and neighborhood look, I'm trying to imagine the looks of your neighbors, as you do this disgusting 😊 dirty job, among the business community type people (nose in the air), out there, but you kept it very clean and dignified. I worked in a vacuum cleaner factory for 23 years in Canton, Ohio, and the equipment they had to cast vacuum cleaner bottoms, GM transmission parts, and drill gun housings was mammoth and dirty. As an industrial electrician, I got midnight calls to go to machine shops and the like; and got to work on a machine that finished 10-cylinder intake manifolds for Winters Industries, for the Vipers. By contrast, your simplicity here, is amazing. Keep up the good work. You are both an artist and an engineer. My little brother spent half of his life with tools cleaning up heads and intakes for just about any kind of racing industry. I can't wait to show him your set-up and work. (He hates computers, so I will have to lure him over for a peek.)
Neighbors are ok but I've learned that when someone asks how something works, unless they are technical, they don't really want to know unless it can be explqained in under a minute. I just tell them I make the pattern, pack it in sand, and when I pour the metal it takes the place of the foam, and most of them seem are satisfied with that explanation. -Know your audience.🙂Best, Kelly
'Fail' or no fail. That was super impressive. 👌👍 👍 👍
Mold media was bad and poor choice of pattern positioning in the flask. Painful fail but easy fix as shown in next video in the series. Best, Kelly
That was an impressive pour! Your lifting rig is really well thought out.
Great job on planning out the pour. Your professionalism shows.
Nice to see the respirator. A lot of content creators have made an effort to highlight health aspects like this. thanks!
Friggin Phenomenal!
Ahhh ok... so some of those imperfections are due to the venting I mentioned. There will be spots here and there that need straight up atmospheric vent sprews to prevent those odd spots here and there. But heck u could get it dialed in then spend the time with a grinder and flap disc, and wire disc to get that polished finished. Cool shit. I was trying to decide if I wanted to try this at home. I used to work in a foundry that molded quite a few aluminum parts. So I learned alot about how the process works. Just didn't know if this was something I could do at home but ur design for the gantry made my mind up lol I'm doing it! Love it!
Murphy is gonna have his due, always
Some sodium silicate sand, in difficult places, might work
Very impressive rig
Looking forward to the next pour
It's true, but it is very time consuming and difficult to pack bound sand in a fragile polystyrene pattern, and it gets very heavy. I've been able to produce much more difficult internally cored parts with unbound sand. I didn't think the pattern position and molding through as well as I should have. Must try again! Best, Kelly
I've been looking forward to this every day since part one. Thanks!
Wow. Just wow. What you're doing is simply amazing.
Great attempt Kelly...I love that you show, "The Good, the bad, and the Ugly" this approach is more helpful
to everyone learning that there is more to meets he eye than just pouring the metal...Love your gantry and it
is something that I had already done, as even 30 pounds is a bit much from a safety factor for me at 66...look
forward to part 3.
Preston, 66 huh - a mere spring chicken - add 10 😊... Martin
Talk about a sweet setup!
You're my hero
What a ride SoloMan! (no disrespect). You were this >------< close. When your team is two people down in a crew that should number three, it's to be expected. You're not called the SoloMan for nothing. Very impressive. I hoped for success but but treasure the hard knocks too. You'll get'em the next time. If it wasn't challenging you not would be in the game. And I'll guess we bystanders may not be standing by as faithfully. We live for the challenges. Even if they are experienced vicariously through others. Thanks for the education & memories. 🎶Signed by the secretary, Harper Valley P.T.A. 🎶 Cheers from So.Ca, USA, 3rd House On the Right
This is absolutely fascinating!
As a welder and fabricator, I am damn impressed with this setup. Damn impressed.
WOW! Very Impresive Home Maker !! More Like A Pro Whos Doing Things At Home.
Absolutely awesome! So glad I found your channel! I get tired of learning from amateurs and cannot afford industrial...yet.
Bet The home Owners Association loves you. What does really awesome love to watch it
I tell them to refer all complaints to the HOA President........that's me 🙂
@@kellycoffield533 ok hells ya sweet deal their.. This work is amazing by the way.. Keep up the awesome projects
Amazing. Even though it wasn't perfect, the results were better than I ever thought possible in the driveway. I want to do my own. Get a better microphone, and get a steady buddy to shoot the video. More fun than a tripod. Subscribed!
Ouch- you really paid your dues on that one. I read enough about casting to know there's a million ways it can go wrong.
Once I saw his poring rig I thought, If this guy cant make a home made cast inlet manifold in his yard, no one can.
Absolutely beautiful.
Great job!! Amazing gear!!
That's an awesome set up
Brilliant! Absolutely brilliant!!
Bro no cap, you're a lvl 10 warlock.
This man is nuts . love it
Nice complex project, but the preparation for a large pour is next level. I subscribed because I know there is much I can learn from you just based on 2 videos. Well done sir.
OUT=STANDING First class work on design and execution of your pouring rig too,,,Just wish you had a partner there with you in case something went south inn a big way. - You are too valuable to get hurt. Cant wait to see the machining.
cannot wait to see more like this! Cant wait to see these parts in action too
Can't wait for part 3 !
The pouring Tongs worked out Great. Really cool to watch. Too Bad about the part for sure. Good luck on the next one. I look forward to seeing how you do it again.
Maybe a 55 gallon drum cut in half to make it easier to work with? Or a box? Something lengthwise? The big foundries have a big sprue roughly the distance of each runner. Like 4 big sprues with a horizontal part.
You are the BOSS, how much shrinkage do get dimensionally
So close! Bummer. You'll get it next time...
I'm retired none machinist, I picked up the machinist hobby 25yrs ago. What i've been working on for the past many years is a model V10. I think mostly becouse I work with engines since I was 10. Lot of the parts involed in my build are cast parts being there is the lest amount of machining. Some part where easy, some not so easy. For help with the not so easy parts I have been following U tube such as your site. And yes you have been most helpful in corecting problems such as in gas venting in lost foam casting. I'm like my dog a Yorkee, once she gets to know a person they regert it, never leves any body alone, thank you for your help, whats your Email so as i may pick your brain, I'll be looking for that forum you talked about.
Have you thought about using a venture style vacuum to transfer the sand from one container to another?
It's how we move plastic in the molding industry, sometimes it's as hot as 400F. It might be worth a look.
Sorry but I am happy I get a part three.
Firstly, I love your foundry setup, it’s put together so well.
I have nowhere near as much experience as you but what about mixing up some sand with, is it sodium silica??? You know, the stuff when exposed to co2 it goes hard? I know orientation of the foam will probably solve the issues.
Lastly, do you reuse your sand? If not what the heck do you do with it after a
Scraping it up off your driveway?
I am thoroughly enjoying every video you come out with, thank you very much for sharing.
I have occasionally used ss bound and even some green sand in difficult places but it can cause as many problems as it solves. In lost foam, when you get it right, it's generally not needed and demolding is just dumping sand. I do reuse sand in fact have for five years now. I have a sieve that sit's on top the flasks and I just shovel it in. It does degrade over time. It's cheap and I should have replaced it before this pour. You should join TheHomeFoundry.org. There are detailed threads on this project, many others, and all of my equipment builds and process development from the last five years. Best, Kelly
Awesome. Did you build your furnace set up?
That was a really well coordinated process. I'm wondering if loading of the internal ducting with sodium silicate binder sand and a CO2 set of that prior to your sand pour would be a good way to ensure full metal exclusion from the ducts.
Thanks Graham. In rare instances I have tucked a blind hole with bound sand but in general I avoid it because it's easy to damage or distort a foam pattern when packing it. Foam patterns are certainly strong enough to handle their own weight while being vibratory packed, but even so, great care must be taken not to distort them with shifting sand. In this case, if the runners were full of bound sand, the pattern would become quite heavy and I doubt it could handled at that weight without distorting or breaking. The primary culprit of the fail in this video was degraded sand that would not easily flow under vibration. With slightly different positioning, I was successful on my next attempt shown in the follow on video at my channel. Best, Kelly
Does the foam not leave any impurities in the aluminum?
So u can fix those spots by making a sprew to those ends with like an 1/8 dowel rod to each end. Then ur aluminum could fill to the tip and u won't have that issue
Not so. People confuse venting in conventional open cavity sand casting with lost foam casting. In lost foam casting, gases vent through the entire surface of the permeable pattern coating. Vents dont apply because they are blocked by foam pattern until the pattern evaporates and by then, they are blocked by molten metal and are not a vent. People think they need a vent because they see gas bubbling back through the sprue but that's because of inadequate coating permeability, and poor casting and feedsystem design. The fail in this casting was caused by poor mold packing due to contaminated/old sand that no longer flowed well when vibrated. If you skip to parts 3 & 4 of the same series you will see the proper result. Best, Kelly
How do you come up with the dimensions to make the parts to glue together to be like the original?
A lot of measuring and strategizing to break them into the most managble pieces for indidviual 3 axis machining. Beyond that it's just allowing for shrink by making the apttern 1.3% larger. Best, Kelly
KELLY U DA MAN
How did you make the pattern for the intake
I saw a guy who put a copper bat through the sand, used a torch to help heat the sand a bit to slow the cooling, then ran water through to help with cooling, I don't believe the little bit he did really helped or hurt anything. He was doing sand cast, but I think in a setup more like yours, having a .250" tube , with resistance wire inside, insulated with a fine sand, then coil place about 2"off the wall of the barrel, before the sand, then a .500" tube near the same location, to allow cooling, heat the sand up to about 100°F just before the pour, , then then about a 4-5 gph flow of cold water, I speed up cooling, would this be safe? How hot can the foam safely get without warping, because 100° f is nothing relatively speaking, I could see it helping if it's 10-20°f out, but 70° the difference is nothing.. would the effort in normal conditions be worth it? Id like to cast engine parts, intake manifolds, maybe someday cylinder heads, or possibly small engine engine blocks, or possibly even remake old engines , from late1890's to around 1920's early 1930's stationary engines, oil field engines, maybe a modified design version, made from aluminum instead of iron, as far as the cylinder and block,/ crank case, I'm thinking as large as 6"bore to 8" and 12" stroke, or small as 4" bore 6" stroke, in an opposed twin boxer 4, low rpm work horse, to run a generator, possibly a 600 rpm, 1800 absolute peak RPM, making it a oil/ diesel burner would be nice, inject fuel with a high pressure air blast, working similar to a paint sprayer, atomising the fuel, possibly using a multiple stage compressor with the injector compressor taking in 100-120psi,+ into a 2" bore, 2" -3" stroke then compress the air into the fuel injector, spraying the fuel, using a a tiny piston injection pump, throttled by a secondary piston that removes the fuel by adding volume , reducing the ability to pressurize the fuel, possibly use modified lifters as pistons, using a cam to , the air injection may require higher pressure to operate correctly, using a compressor to store air at 120psi, then be compressed again after a slight cooling time, being compressed into a small storage tank, possibly 300 psi, then enter the injector pump/ compressor. Filling the 2"bore with 300psi, the actual pressure would depend on the. Injector and compression ratio, but can possibly be in the 350-400 range the engine having roughly 24:1 compression , spraying oil, used engine oil used vegetable oil, or diesel , kerosene, being sprayed similar to how a paint sprayer would spray, the added air should greatly atomised the fuel, also use heat plugs, and fuel line heaters, and a injector heater, heating the fuel to 200°f just before injection, allowing a cold air intake, dense as possible, then the hot fuel injected as the cylinder pressure peaks,.
Possibly use semi truck wheel bearings as crank main bearings, use two 24" flywheels, weighing around 60-80 lbs each use a hub to bolt on to the crank with the flywheel, with a 1.5"& 1" shaft, to drive an alternator, and fan, whatever maybe needed accessories wise, with a 2" and 3" for the serious business end, and make them interchangeable.. use a SBC water pump, to bolt to the water jacket, to circulate water from both banks, both cylinders being the same, the other can be blocked off, making a Rh and Lh engine, making a crank change, and adding a cylinder pair, could be all required to go from 2cylinder to 4cylinder , or 8cylinder, I think this would be about it, use 6-8 v per cylinder with overhead cam , use say 3x 2.125" intake valves, and 3x 1.880" exhaust valves,, the spring pressure could not need to be too great, being rpm is low, possibly in the 20-30 psi seat, and 50-60 on the nose, at most, with roughly
.500" lift maybe .750" use 3 1.5" exhaust into a single
2.5" per cylinder, with high port intake and exhaust, the intake uses 2" per valve split from a 4" tube, with a cone filter, with an emergency flap inside, Incase of runaways, maybe use a governor activated release, to close off air , if it reaches 2000rpm, use a governor to maintain a steady 800-900 or 1200 rpm, if I had access to a mill and lathe, and help casting the parts find old diesel engine pistons to cast new from, possibly using a heated mold and press to cast the pistons, possibly cast steel cylinder liners if a steep tube can't be found to make them from, bolt on the water jacket like a motorcycle cylinder, then the water jacket use a o-ring seal, the cylinder liners using a steel o-ring and copper gasket, possibly using a aluminum crush ring with two rings on the jacket one on the head,
Sorry to ramble, the insomnia has me up late, I want this engine , to generate power, I'm hoping the 2cyl version would make atleast 150-200 ftlbs TQ. And 40-50 HP, to near 300 TQ, and near 100hp at 1800rpm probably with a bit of boost a small superchargers, I'd probably start with a 4" bore version, with 4.5" maybe 6" stroke use 4valves / cylinder, use a more traditional injection, with a heated injector spinning at upwards of 2400rpm, it would be a better starting points, , sorry to ramble again insomnia is horrible..have a awesome day!!
That's really really impressive. How much time do you estimate you have in making this start to finish? Again, hats off man that's a hell of a project
Hobby stuff so I didn't keep track of time. When it's fun who counts? When it's money.....different story. There was a lot of equipment upgrades I did along the way to mold and pour a part this size that won't recur. I spent a lot of time engineering/designing the part and features versus making the pattern and foundry work. With all that behind me, and now that I'm using a CNC router to make foam patterns, the next one would/will be a small fraction of invested time. Best, Kelly
GOOD
II really enjoy your blog and have tried 3 times to join the forum but have been unsuccessful. I followed the instructions but must be doing something wrong. Thanks, Joe
Here's the link on how to join the forum. You need to click the contact button at the bottom of the page. If you still have difficulty, let me know. Best, K
forums.thehomefoundry.org/index.php?threads/joining-the-forum.1999/
In Lost Foam technique, does the molten aluminum burn the foam out? Or do you bake or “fire” the core to clear it before pouring it?
The molten metal evaporates the foam pattern while in place in the mold. The foam undergoes two phase changes; solid to liquid, liquid to gas/vapor. The latter is closest to the molten metal front and passes through the permeable pattern coating into the sand mold and as it does so, it alows the molten metal front to advance consuming all the foam while the metal pressure holds the loose unbound sand in place. Best, Kelly
Hello Kelly Coffield I enjoyed these vídeos. If you need to attach 2 or more pieces of foam together, how do you do it?
It depends. If it is a small joint where the glue can be applied and the parts joined in 10-15 seconds, I use low melting point hot melt glue. If it requires long working time, High Tack Poly Vinyl Acetate (white) glue. Laminating is a longer discussion. I have another video on lost foam materials with more discussion. Search my channel. Best, Kelly
On the topic of using vibration to pack the sand around the molds, I wonder about using air injection to induce liquefaction of the sand and allow it to flow around the molds.
There was a similar question asked in another video. Here's my reply: Fluidizing the bed is fine for removing the casting from the packed mold or possibly placing a pattern in a filled flask but it's the opposite of what you want to do a tightly pack a mold. Vibration makes the mold media act like a solid. Fluidization makes it act like....well, a fluid. When you turn the fluidizing air stream off, the sand isn't packed but more akin to having just poured it into the flask so it would still need to be vibrated to have good mold stability and integrity. I had a fluidizing coil in the bottom of my old molding rig. I never used it because I still needed to sift all the sand between uses to remove any loose refractory coating or clumps resulting from the byproducts of the decomposed foam. To filter the sand, I just cut the bottom out of a bucket and replaced the bottom with a perforated plate/screen, place it on top of the storage bucket, and shovel the used sand through it. I also found that with hand placing and filling the pattern and mold, I was better able to avoid pattern damage and deflection than trying to place in a fluidized mold. Best, Kelly
@@kellycoffield533 fascinating. I figured, given the apparent maturity of your equipment, that you’d considered it and had a reason it wasn’t useful. The videos are excellent, keep them up. Personally, I’d find it pretty cool to just watch a timelapse of the foam work that goes into an intake. Wouldn’t even need to narrate it.
a couple seconds in.. oh thank god, the audio is fixed!
Machine shop: where did you get this?
This guy: I poured it myself
Machine shop: …..
Guy: …..
Machine shop: that’s f****** impressive.
Bummer indeed! Oh how the elation of first breakout view turns to major disappointment at failure on closer inspection - we have all been there and as you say modify approach and try again. Love the pouring set up, it looks to be a great success and surprisingly easy to use as it gives you more control over the pour than most crane type crucible lifts - well done - its a good model for others contemplating having to use a crane because of pour weight. I note the suggestion of the use of something like CO2 as a possible solution and I also note your reply as to the problems therein. Even so I think it worth following up on a little as CO2 sand is fairly easy to pack and perhaps a sand based on Fenotec or similar binders may be suitable as it is even easier to pack and may do so with vibration? If so use fenotec sand in place of your current loose sand?? Apparently the set time of fenotec can be varied for 1 minute to 3 hours so plenty of time for pattern immersion and vibration of and into place before set but once set I doubt any leakage will occur. However your comment about weight is noted! Perhaps a thicker coat on the insides of the pattern? Sadly you are a bit on your own here - you are the expert on this process and the best the rest of us can do is guess .😊.Martin
Further to my comment above. I notice that the sand tank is pivot-able, could you perhaps extend this idea to a sort of gimbal arrangement so the tank sand mould assembly could be moved through various angles in all directions as the vibration occurs. Obviously some sort of temporary lid would need to be on the sand to stop it falling out when the angles get steep enough to ensure proper pattern sand contact... Just another stupid idea 😏... Martin
@@olfoundryman8418 Thanks for those thoughts Martin, always much appreciated. You know I will not give up easily. I do occasionally (modestly) tilt the flask when filling/vibrating in an attempt to pack difficult features. You have to be careful because what usually happens is the media in the top of the mold/flask moves to one side and the bottom remains fixed and it the uneven sand pressure can distort the foam pattern, sometimes severely. It's far better to position the pattern wisely and maintain the sand depth in the flask on all pattern surfaces as you pack/fill the flask. That way the sand pressure remains the same on both sides of the wall of any pattern feature. The commercial LF foundries change the direction of vibratory excitation to move and pack the sand in different directions. The turbine vibrators on my molding rig are positionable for that reason. I've successfully molded and stabilized what at least to me seem to be much more difficult cavities than these runners. You probably haven't had an opportunity to read my failure analysis and proposed corrections at The Home Foundry forum thread on this project, but I will have new mold media, pattern positioning, vibratory packing technique, and make a feed system/gating change. for round 2. When you know what doesn't work, it's easily to postulate why, but don't think I don't do my share of guessing too. ;-) Best, Kelly
@@kellycoffield533 Well, that's what I get for sticking my neck out in an area that I don't know much about 😊. But to risk making a fool out of myself yet again a further thought did come to mind. I was some time ago given some resin core sand based on not sand but rather one of the newer ceramic bead molding materials. These beads were about #50 mesh and surprisingly spherical. If you could get the beads (without the shell resin coating) and use this material as your mould media I wonder if their spherical shape might lead to better packing? Or have you already thought of this?... Martin
@@olfoundryman8418 Nothing foolish there Martin. What's foolish is someone pouring a bunch of molten metal on a complex foam pattern without thinking it through....and then pledging to do it again....like some people I know. :-) The LF equipment manufactures ferrous media offerings are typically rounded media, usually mullite/alumina or zirconia based. In a previous life, I did extensive work with filtration using packed media columns. I learned a lot. Round media definitely can be made to flow more easily with vibration than granular media. I think it can be dislodged more easily too but the commercial operations also use vacuum assist and the pressure differential provides additional mold stabilization. If you can sufficiently vibe granular media it lodges together and forms mechanical interference, almost like a bond. The least expensive source of spherical media in low volume is blasting media, and can be bought in any mesh size, but it is about $1USD/pound. I buy my sand at retail stores because it's convenient. It is sieved to size, washed, and dried, and even at retail levels is about 8 cents/lb. If I was willing to buy it in bulk at 1 ton or more it would be 1 or 2 cents/lb. I cant store a ton of sand. I'm still just a guy casting metal in his driveway with equipment I roll out of my shop. Best, Kelly
Kelly , Again I find myself "preaching to the converted" As I should have realized with the effort and thought that you have put in to make the LF process your own you would have investigated the various media options. It seems that CB media is available ex China at about $400.00 per ton. there must be someone importing it (or even making it) in the US. Even allowing a fair mark up it should be available in a suitable quantity that considering its reuse-ability would not be too unreasonable - if it solves a problem. Perhaps I am wrong (again) but as stated above I was given a 25 Kg bag of CB resin coated to try. I was hardly a big customer so for them to just give me the 25 Kg indicated to me that while it was no doubt dearer that the approx $7.50 I pay for 25 Kg of resin coated silica sand it was not that expensive?? (Wrong again ?😏)
"Like some people I know" - Hmm, yes there is a lot of that on YT. I just watched an admittedly entertaining video on making a casting and as usual it was full of errors from pattern making to casting finishing. I nearly choked when the offer was made to describe the functions of the various bumps etc in the running system in a future video, if the demand was there - clearly the video-er had no clue as to proper gating etc. In another video a gate was cut in a circular way encompassing about 1/4 of a circle from the sprue (massive parallel) base to the casting - it was explained that this curved gate "cleaned the metal" (groan!) And this from a well known YTer of US origin, he has 20 times my sub level - Sigh - its just not fair. Keep up the good work. I await the next try... Martin
Kelly, what grade of sand are you using? Can I also use regular playsand and vibrate? Is that all I have to do?
Play sand will work as long as it is dry, and it often is not. If you already have some you want to use, spread it thin on your driveway in the sun and then gather it. It can also be pretty course with small pebbles, which probably doesn't matter much if you are coating your patterns. If you are going to buy, I use "Quikrete" fine sand because it is washed and dried and pretty consistent size. It is typically available at the big box stores in the section that has concrete and mortar mixes. It's probably about 50 mesh and is inexpensive at about $4/50lb bag. The #1 factor for your LF sand is to keep it very dry, else it is hard to excite and pack with vibration. I also store it in sealed buckets for this reason and because it stinks after use. If you are doing iron LF, you'll probably need higher refractory media than silica sand, like aluminum oxide or zirconia. Best, Kelly
Is there a way to figure out how much alluminum you will need as reguard to foam weight?
The foam is so light you would need a very precise scale, and even so, the density varies enough to make it very unrliable (ask me how I know!). Best is to submerge in water and measure displacement or roughly calculate volume of the part in pieces if necessary. Best, Kelly
U don't have issues with the foam turning into Slag or creating bubbles in ur final part? Just curious how that's prevented. I know in factories they have angles that the part sits as well as correctly placed screw vents at the top of the mold that go to the air and prevent air bubbles in the part. But it looks like u may have solved that by having the part with the right curves and angles pointing the correct direction to prevent bubbles. Idk... waiting to see ur finished part
The fail in this casting was caused by poor mold packing due to contaminated/old sand that no longer flowed well when vibrated. If you skip to parts 3 & 4 of the same series you will see the proper result. You wont have bubbles and entrained gas flaws if your coating is sufficiently permeable, have proper casting and feed systems design, and mold prep. Best, Kelly
Hi Kelly,
Very informative video..
I am facing sand sticking issue to final product..
Can you tell me What's the exact issue in the product..
Is it because of to much binding agent. Or less surfactant
When you say "facing sand", that sounds like you are using bound (green or other) sand. In lost foam casting, a refractory coating is applied to the foam pattern and then it is vibratory packed in dry sand. The coating prevents the sand from sticking or imbedding in the casting and essentially reproduces the surface finish of the foam pattern. Though some people do try to use bound sand in lost foam casting, it really defeats one of the benefits of the LF process. Best, Kelly
How did you make your furnace. It sounds like a good idea
Can't answer a question like that in a YT reply but if you join www.TheHomeFoundry.com and search user name Al2O3, there are links in my signature to the furnaces. Best, Kelly
집에서 하기 좋은 일이야!
사랑스러움
친절한 댓글 감사합니다.
@@kellycoffield533 그대의 위대한 여정 캐스팅 마스터
@@user-lh7jj1eb5w 때로는 여행이 목적지만큼 즐겁다 Kind Regards, Kelly
Could you prefill the runners before putting the pattern in the sand?
Possibly with a bound sand but the foam pattern is probably too weak to being packed and handled with the weight of the sand. It's not necessary. If you view part 3 you'll see the corrections made to successfully cast the part. Best, Kelly
Rig looks great Kelly! That's a whale of a crucible.
I'm not competent to comment on your fine work but I will for my ego.
The defects you have are hard for someone who does not lost foam cast to understand. It is where the sand did not get packed around the pattern sufficiently and the refractory coating does not hold the metal in. That's why Kelly refers to it a a leaker. Very frustrating to have happen, and it seems so obvious after the pour.
Kelly: Have you tried to pre-pack difficult areas? I've thought about filling with sand with a foil tape cover to hold the sand in place during handling. Don't know whether it would work because I haven't tried it. In my experience the density of the packing is not critical so long as there is not an unfilled area. For me, the vibration is just to get the sand to flow, not necessarily to pack it.
I'm looking forward to your second pour for the money. Do you see any pattern changes you want to make now that you have a casting?
Pre-packing certainly can work, but for this part, packing the runners would make it too heavy to handle the polystyrene pattern. Vibrating actually does increase the packing density (10-15% typically) and causes the particles to settle into a more tightly/pseudo bound state. Try pulling an object out of a barrel that has just had sand poured around/on it versus vibrated in place and the enhanced packing will be quite apparent. I was asleep at the switch when it came to molding the part. I'm going to have another go with a different pattern position, fresh mold media, and staged vibrating while filling. Best, Kelly
@@kellycoffield533 I hadn't thought about the weight of such a large pattern. Good point!
I vibrate my sand and know it packs it in tightly. I'm not certain that is of much value in keeping the metal in the refractory however.
Have you had failures due to lightly packed patterns? I've not, on simple patterns where I didn't need the sand to flow.
@@andrewmartin4258 For the most part, only in severe undercuts and blind cavities.
How much did the customer pay?
Which matrial use for pattern making??
Owens Corning Foamular 150 Extruded Polystyrene insulation board. If you search my channel for this title "Pattern Materials for Lost Foam Casting" there is more information about materials. Best, Kelly
What devices do you use to vibrate your sand?
Pnuematic Turbine Vibrator. Search them on eBay or Amazon. Best, Kelly
@@kellycoffield533 thanks it sounded like you were using an air chisel until I watched this video again.
Does the sand stay loose like that,. You don't add any binders?
Yes. It's vibrated in place which tightly packs it without binders. It's perhaps the most attractive feature of lost foam casting.....no cores or worries about parting lines and draft. Best, Kelly
@@kellycoffield533 Thank you for your reply .
I saw in you other videos you made ,.you dipped the foam in some sort of slurry!
So when that hardens , that will be the outside of the mold which will keep back tue sand once you poor in molten aluminum.
@@kellycoffield533 If you don't mind me asking you one other question about the fioam.
So when you poor the aluminum inside the mould, what happens with the foam, does it get burned away .
Also I was quite surprised when i didn't see vent holes.
Thanks ..
@@Ray88G As the molten metal consumes the pattern, the portion in contact with the pattern is melted/liquid polystyrene and the portion in the liquid PS and the molten metal is gas/evaporated PS. The refractory coating on the pattern is permeable and although some liquid can pass, it is mostly in the form of gas. This is why there are no vents because the entire surface of the pattern vents gas as the metal advances. Best, Kelly
@@Ray88G Yes, but it's really not a structural part of the mold and serves as a permeable coating (as described in the reply above) that also improves surface finish of the casting. Best, Kelly
Before I retired, my place of employment tried to develop the styrofoam evaporative casting process to an industrial level. Years of experimentation and process development went no where. I'm sure other companies do it and do it well, but we were cast iron. Now cast iron is an almost dead material. Too heavy, to much CO2 exhaust.
Here in the US, Lost foam hasn't gained much commercial traction. Sadly, most of the research, process development, related process equipment manufcatures, and commercial practitioners reside in China and most foundry use is in fact for iron castings. There are a few US foundries using lost foam. Mercury Marine in FonduLac Wisconsin for example. Best, Kelly
Maybe you could add a door or two at the bottom of your rig and just open the doors and turn on the vibration to empty the sand rather than dumping it out of the top.
That's not a bad idea. I have a vacuum plenum in the bottom of the existing flask. I did discover that I could controllably tilt and dump the full & fully extended flask so no more trying to knock off th etop extension before the dump. Best, Kelly
Would you possibly be interested in a side project? Im in the process of building a foam intake manifold "much less detailed than yours" for my Cobra R clone...... basically a 2000 Cobra R intake lid, i already have the lower intake i just need to make the upper "hat" part..... let me know if its something your interested in, i understand this wouldnt be cheap
There all side projects ;-). Post your contact info or contact me through my website www.inlinecarb.com. Send a picture and description of what you are looking to do. Best, K
@@kellycoffield533 awesome thanks! Just emailed ya
@@kellycoffield533 if you do this, and please do this, please share with us when you you do it.
@@jkepps Second pattern is done so attempt #2 will be forthcoming in the near future. Best, Kelly
Está peça roxa e isopor
The foam is pink but it has a refractory coating that is blue/grey. Best, Kelly
@@kellycoffield533 interessante
@@kellycoffield533 quero produzir um cilindro de moto.tem como
@@kellycoffield533 vc tem links aonde encontro esse produto refratário
@@marciomila9264 I have a video called "Refractory Coatings for Lost Foam Casting Patterns" that discusses the refractory coating.
nothing wrong with watching some guy casting metal in is from yard on the internet
Well that sucks. Maybe next time.