I can tell you about helping my friend with heat resistant fire cement. He always said that make sure the particles of vermiculite and perlite be of the smaller size and you will not have any issues with cracking. He used clay from a river stream. Really nice stuff and FREE !!!!!
As I understand it, a termite mound is pretty much local clay, where the termites have done most of the work in separating it from the other soil components.
There's a pretty awesome video where an African village smelted iron using traditional methods, basically the village elders recreating from memory what is otherwise a lost art... They use a termite mound as their clay source. The video is posted by Christopher Roy, titled "Smelting Iron In Africa (A DEMONSTRATION)".
Clay has been used for building things since man played with fire. The ants just made sure the clay is set to ant standards of building. Natures knows best fella.@@LittleAussieRockets
Nice build. FYI, its a 'furnace'. A foundry is the whole set-up ( building, plant, etc). A Forge is for heating metal, so you can then shape it ( blacksmithing). If you are working with Aluminium, you want the temp round 700c. As I understand it, too much heat will leave you with a porous casting. 👍
Gorgeous! Looking forward to the next video. Just want to say I'm glad to see the video quality showing forth the effort you clearly put into it! Job well done, and keep up the awesome vids!
For melting aluminum, pearlite and vermiculite will work fine, but at higher temperatures, like for melting bronze and iron, those materials act like a flux and it lowers the melting point of the material around it. In a way it sort of creates a type of glass that weakens everything around it. Clay and sand mixtures work a lot better for high temperatures. Basically the higher the alumina content of the clay, the better. It takes a lot of trial and error to find a good clay/sand mixture that works well. If you want to skip all that, one of the easiest and best performing ways to make a furnace is to just get a metal cylinder, line the inside with 3-6 inches of Kaowool then coat it with a layer of castable hot face like ITC 100. That stuff has a melting point of 2482°C and is used to reflect the heat of your furnace back into your crucible.
ITC 100HT is way too expensive to use on its own, but this is very nearly correct. One should use a stabilizer on the refractory insulator to protect it from shock and slag, coat the stabilized refractory in satanite refractory cement to give it rigidity, and then coat the satanite in the 100HT. That stuff is like $75USD a pint and a pint is at least enough for 2-3 projects this size. I don't trust 100HT for structural support and will use a SS tray anywhere that it might get hit by slag. The 100HT is primarily desirable for heat up time reduction and heat retention. It reflects IR radiation when it gets to a high temp and increases in efficiency of reflection the hotter it gets up to its thermal limitations. I'm about to build a small propane forge with this method and an Aussie style adjustable self aspirated burner. If I'm wrong about anything I've learned from trusted sources in this, I'll edit the comment with what failed and how. TL;DR: Satanite is $1/lb, 100HT is $40/lb. Use stabilizer on kaowool or carbon felt. Use satanite to give it physical durability and add a small additional insulation layer. Use 100HT only for its IR reflective properties so that it pays for itself after 200lbs of fuel are used.
@@LittleAussieRocketscheck my comment above. Kaowool or similar ceramic alumina refractory fiber insulation MUST be treated with a stabilizer to be safe to breath around and prevent damage to your insulation. It needs to be further protected with a cement. ITQ 100HT is incredibly expensive and should only be used for IR reflectivity because of that. Manufacturer instructions say the specific coating thickness for efficacy. I've heard it reduces fuel costs by about 20%. I don't know if time and twig savings make $75USD worth it, but using a purchased fuel source would justify it.
And this is what you do in your spare time? You need to find more spare time, and what would happen if you made it accelerated to 88 miles per hour. Great Scott !
I used to do a lot of freehand on pipe, especially the root pass. Tubing that small, I likely would have freehanded that, but it never hurts to practice or polish-up. If you want to weld that stainless tubing without a purge, and have less interference in your weld structure/appearance, keep your welding downhillish as you go around the tubing (same with welding any gaps for stainless). That is one hot stove (furnace) 🙂👍 Pretty cool 😏
Your furnace is brilliant!!!! Once you get some appropriate furnace tongs to grip the crucible the pouring will be much safer. You can use your lifting tong then switch to a pouring tong if you like. I was so impressed with the termite mound as a furnace lining. We used gannister and fire clays/bricks together with high end ceramics etc. I can assure you your lining stood up as well as anything we did. You can do patch repairs but I expect you aren't going to be pushing it hard. The use of the k type thermocouple was great. You can also get cheaper one shot dipping thermocouples but maybe that would cost more in the long run. Then theres IR but do you really need to go further. When you consider safety gear a good thick leather metal workers apron is a real benefit and although the safety officer might complain wear your boots slip shod so you can flip them off instantly if metal gets in. Seen many a leg saved from cremation that way. Shedding molten metal is better than holding it in your clothing. Maybe you have looked on line for foundry supply companies for an idea of all the safety wear. I would go with heavy leather gauntlets, leather apron, leather boot covers, leather boots, full face visor and fresh air flow. Out of touch with the market and only really knew one tooling company in Australia. Can I say water is the enemy in casting. On top of metal okay. Under metal run. That vlog is the best thing I have seen in ages. Learnt so much good stuff watching you. More power to your elbow. Many thanks. Please keep on with your brilliant work. Its inspiring.
Best comment. Water is scary, scary. Everything you said is on point. I'm using IR reflective ceramic coating in my forge builds, but using twigs as fuel, I don't think the cost is justified unless one had enough 100HT left over from another project where the fuel savings would pay for it.
Finally, I got to see the finished product! I've been waiting for it for so long. If I were in Australia, I would definitely buy one too 🤤! I'm also glad you like our machine! Keep on welding, you superstar!
Perhaps vibrant the insulation mixture when filling , I did using a needle gun on refactoring cement, and was surprised how much air was entrained in the mix , a most interesting video thank you .
I've made me a pair of tongs that is featured on my channel. However the design needs a lot of work. Btw, whenever I was thinking about making my furnace. Never in a thousand years did I think that thin pieces of steel would stand up to the heat. The same with using a shop vac for air flow. I would have thought the plastic impeller would melt immediately. Shows how wrong I was. Impressive stuff.
Molten metal??? I say you have reached Rocket-Stove Mecca !! You are a master when you continue to top yourself Top of the craft spot is where you are at🧐🙏🏻
Amazing project and well put together content. I’ve been looking into all of the different ways(electric, gas, oil, etc) to heat a foundry and this is unique. Reminds me of what was done here in Australia when there was no fuel. Plumb fire wood plasma straight into the combustion chamber. 🇦🇺🤜🏼🤛🏼🍀😎😂
Great stuff, a super charged rocket stove/furnace. It certainly works, you melted a charge of aluminium, that's brilliant! Yes it's called a furnace and you would use a 'pouring shank' to hold and pour the crucible.
My great grandparents lived in a bush camp on North Straddie, and they made their wood-fired oven out of termite cement. I have found perlite doesn't do so well mixed in - as it breaks down into dust with only a fraction of the original volume. Vermiculite falls apart as well, but doesn't seem to completely disintegrate as much. (On the other hand, for hydroponics I prefer perlite to vermiculite due to the open space). Once again, informative, entertaining and impressive.
A Foundry is the place where you melt and cast metal. A furnace is the item that you melt the metal in so you have made a Furnace to melt the metal in you Foundry. How would hardwood like Iron Bark go it burns a lot hotter than pine, that would be interesting to know. Great job I look forward to you videos.
Just come across your channel, this is super cool! I built a rocket stove forge for making knives, I used some scrap stainless tubing inside an old beer barrel, with forced air and enough wood I can get steel bright orange without much hassle, it's incredible!
I will second others on the naming. Once upon a time when I taught metal working, we had a forge which was for heating up metal for banging on, and the air/fuel ratio could be adjusted to be carburizing/neutral/reducing. The furnace was for melting aluminum and brass. Someday I would love to build an electric arc furnace and melt steel for pouring anvils. But for now, looking forward to that welder.
The only things that I would do to improve it is add some type of insulation between the burn chamber and the melting chamber. The other thing is to add a handle to the top of the melting chamber so you don't have to touch the top to swing it.
For heat, cheat. Grab a bag of coke. Use wood as primary heat source, add a handful of coke every now & then to boost. As far as your tig welding goes, geez, for a guy who ‘apparently didn’t do much’ great job. I’m the undisputed King of Dip! Trust me, 🤣🤣🤣. Tig has got me bluffed 😂😂 Bloody nice final product, well done.
I really like this design. What a cool option over expensive gas. Some time ago I did a deep dive into cob ovens for pizza and baking. There are a range very specific ratio mixes of clay, sand and cellulose (straw, grass etc). The old timers wound that termite mounds had these ratios perfect. No need for sifting sand for grain sizes, no need to experiment with your particular local clay to soil ratio, and no need to chop up straw and mix it in. As for the straw, it's not really possible as a DIY to get it chopped small enough and mix it evenly. The termites have the cellulose particles in such small sizes and mixed perfectly. The Clay to sand/dirt ratio is important as pure clay will shrink too much and not handle the heat cycles of uneven heats causing huge cracks. The cellulose particles will burn out leaving tiny air pockets which will insulate.
I considered building a furnace with the combustion coming from a wood gasifier (fema or imbert design), but without the syngas cleaning and condensation part. The problem was in the suction to exhaust the gas in the burning chamber, fans would not work in the medium-long term in direct contact with the gas due to tar impregnation on the blades, it would have to be with a venturi effect and very strong to work (probably compressed air). Its design based directly on a Rocket-Stove is more cost-effective to do, even though the burning process has a lot of moisture from the wood/biomass due to the lack of a pre-drying chamber, the cold air doesn't help either.
I think it is getting hotter than what your thermocouple is showing. Your stainless tube is only glowing dull red but the graphite crucible is glowing bright white. Could be that the material doesn't fully combust until after the thermocouple. That's good news or you'd melt the whole thing down.
Very Nice build. I melted Ally with wood years back but have had people say it won't work. You showed the flaws in that! If you want a lot of heat, make an inlet before the thermo couple and have a little oil going in there. You will push the numbers way higher with that.
the problem with wood is the residual 10% moisture will cool your foundry when adding new fuel before heating it back up. i read somewhere roughly, 1/3rd burn time it sucks heat out of the foundry, 1/3rd it burns of volatiles and the last 1/3rd its a pure coal fire. The stove design continuous feed solves the biggest flaw of my setup below, in my forced air brick foundry i could melt 4 kg aluminium in 40 minutes from cold start, but when i tried 1kg copper it took over 5 hours burning through 3 wheelbarrows of woodchips I mean the people with the syphon nozzle sometimes use an air drier in their hose
At least with forges, typically you'd do the lining and a light fire, look at the cracks and then just put a thin slurry over them which will generally hold up ok. Ultimately though, refractory material is a 'wear item' which is getting replaced eventually and don't get too attached to it being there forever. In terms of the fuel, I think you're probably hitting the peak with the timber and nuts, if you throw some charcoal in there I can easily see that getting well into the 11-1200C. Through summer you might want to chuck a mesh spark arrester on the top so it doesn't set the countryside on fire as much :) Oh yeah- you can make crucible tongs easily enough with a rimmed crucible, for the larger types that don't, you'll want what's called a cradle, which is essentially a round loop and a clamp which comes in over the top to stop it tumbling out when turning sideways
When mixing the termite mound clay, try adding some loose fiberglass into the mix, We do this here in Scotland and it helps bond the materials when its dry and the results are much less cracking through use. love the temps you got on those palm nuts very good video as always
What you have made is a furnace when used to smelt but a hearth when used to heat metal for forging. The building or location is a foundry when casting metal and a Smithy or Forge when forging. Hope that helps.
If you add a small light weight flap check valve in the fuel shoot just above the air input then you might be able to get it to blow shut when you open the lid, and then when the pressure equalises with the lid on it will open and drop in the fuel
Great stuff! Exactly the design I was looking for planning my ground furnace upgrade! Right now it has the same hole firewood and crucible go to but I was thinking quite a lot to separate them:) Thanks!
Also, over here in NZ they have a type of tea tree call Manuka which is notorious for burning out pot-belly stoves. Maybe some of the Aussie tea tree timbers would have similar properties? The palm nuts would also have an advantage over the pine, in that they have a better surface area : volume ratio.
So wood burnt down to charcoal. The best quality fuel for smithing, low impurities, low ash, but has a short burn time. But if you want to see moths being drawn away from halide lamps and into an open flame, coking coal can do that. It's dense enough that the high airflow won't blow it away.
If you could find a way to use the exhaust to preheat the blast air a high percentage of that preheat temperature should get added to the furnace temp.
What about a secondary air intake at the base of the chimney, where the flames start swirling? Ideally, that air would have been heated along your burn chamber.
30:11 Difference between Foundry and Forge... A foundry melts metals in special furnaces to be cast into molds. A forge is a furnace or hearth where metals are heated prior to hammering them into shape. The act of forging is heating and hammering metal into a shape.
put in a flow control for the air intake. it is running very oxygen rich. you probably only need about half that air flow but start by 10% reduction and test temps. tyo much air cools it down faster than it can generate heat
Your thermostat should be in the crucible area there is More combustion happening after that first reading point. Is hotter in the chamber and you can always load char to boost temp. Run a blend of fuels.
Looked like the exhaust hole in the lid needs a spark arrester - it will have to be the same size as the lid and fairly tall as to not melt itself with the extreme heat [and sometimes fire] coming from the exhaust hole, might also function as a radiant heater as I assume it will glow red/orange from the heat
You don't actually need any extra air supply. The easiest way to get a hogh air volume draft is... adding a draft. On the exhaust side, add a 2m pipe, and it'll just suck air in from the bottom by itself. And really lots of air too. I don't know if it'll equal the amount of air a forced air system delivers, but it's inexpensive and probably very effective.
Have you tried using a old diesel turbocharger. Taking a part of the exhaust and injecting into the intake. Using a high speed motor. You have to fab up a oil lub system . This should get the temperature up much higher. Who knew nuts could melt metal.
Great Content my friend! I'm will make an above ground pool(8500gal) heater. Trying to figure out the best way to transfer the heat from wood to the pool. My plan is to fire a water filled 55gal steel drum with protruding angle iron nubs inside and out on bottom with a forced air rocket stove. Plan to use 2, 3 or 4 - 2.5ft length 3/4" copper pipe radiators coupled to a pvc manifold both sides of the drum , in the heated water drum to transfer the heat to the pool - using 1 1/4" pvc pipe with pool pump. High volume is key here, aprox 3000gph, looking to heat the output water to about 100f max or less. Would it be better to heat the copper pipe in a direct flame? I did play around with direct fire heating with my smokeless firepit but the cold coil copper extracted way to much heat from the fire causing terrible burn quality. Thanks,
small thing I would consider is to insulate the fire box. If the heat doesn't radiate out to ambient air (glowing tube) then the hot air will maintain more energy. It would be cool if the foot lever for the lid also opened blow-off caps or actioned baffles to redirect the intake flow so that it wouldn't be blowing into the firebox when you're more than likely working right above it.
Oh pt2: I looked into your vacuum and it may have a universal motor, which means you can wire up a 10000W SCR voltage regulator to throttle the motor speed
I actually had to reduce the airflow by venting off 1/3 of the air with a 3D printed part. The full power of the vacuum cleaner basically blew the fire out.
The temp inside the furnace may have been higher than the burn tube. The burn tube is closer to cold intake air and the furnace is able to retain and gain more heat as it is lined with refractory. Nice to see your journey. I must restart my own.
If he had insulated the combustion tube, the temperature sensor would be in the correct position. Everything in the forge can be heated to the maximum temperature of the flame. The flame temperature at the entrance would therefore represent a maximum temperature.
Having talked with other people about this, all the termites have done is separate the clay and soil to create a very pure and clean clay mixture. The only thing the termites have added is tiny amounts of organic matter. I think you could replicate this by adding wheat husk or wheat bran, which would burn out and create tiny air pockets increasing the insulation value of the clay.
7:35 My Mum had a cake tin shaped like that. Great furnace mate, I'm just wondering how much heat ironbark would generate ? Just a thought. No more candles?
I don't have exact figures on the ironbark temperature ranges as I didn't have the thermometer installed when I was testing it. Sounds like I'll need to revisit this maybe with or without candles. We'll see 😉
I'm going to have to do an in-depth video where I run all different fuels through it. I intended on doing that with this video. I just ran out of time.
Yes, that's correct. That's pretty standard practice for low pressure applications, particularly around the food grade industry, which is what I do most of my work in.
just a constructive criticism because ive watched your vids for years. you need to pay more attention to your audio levels when editing the videos, no matter what software you use there should be a VU/sound meter somewhere that shows the audio level, you need to keep it at least mostly in the green and sometimes in the yellow and if it only hits red once or twice quickly that is perfect. i had my tv turned up all the way and half of what you said i still couldnt hear.
@@LittleAussieRockets all the software ive ever used allows you to edit the individual clips audio level to normalise them, in fact if you wana get tricky you can do some pretty advanced fades and stuff to normalise audio but if you just keep the audio mostly in the yellow without is going too far into the red {otherwise called clipping] the audio will pretty much be perfect for your audience. keep up the great work.
This YT channel should be mandatory for high school metal shop classes.
I can tell you about helping my friend with heat resistant fire cement. He always said that make sure the particles of vermiculite and perlite be of the smaller size and you will not have any issues with cracking. He used clay from a river stream. Really nice stuff and FREE !!!!!
As I understand it, a termite mound is pretty much local clay, where the termites have done most of the work in separating it from the other soil components.
That makes sense
There's a pretty awesome video where an African village smelted iron using traditional methods, basically the village elders recreating from memory what is otherwise a lost art... They use a termite mound as their clay source.
The video is posted by Christopher Roy, titled "Smelting Iron In Africa (A DEMONSTRATION)".
Clay has been used for building things since man played with fire. The ants just made sure the clay is set to ant standards of building. Natures knows best fella.@@LittleAussieRockets
Nice build. FYI, its a 'furnace'. A foundry is the whole set-up ( building, plant, etc). A Forge is for heating metal, so you can then shape it ( blacksmithing).
If you are working with Aluminium, you want the temp round 700c. As I understand it, too much heat will leave you with a porous casting. 👍
That washer trick is GENIUS! Thank you for sharing!
Gorgeous! Looking forward to the next video. Just want to say I'm glad to see the video quality showing forth the effort you clearly put into it! Job well done, and keep up the awesome vids!
You need more chickens in your videos. That's a golden touch on a badass channel.
For melting aluminum, pearlite and vermiculite will work fine, but at higher temperatures, like for melting bronze and iron, those materials act like a flux and it lowers the melting point of the material around it. In a way it sort of creates a type of glass that weakens everything around it.
Clay and sand mixtures work a lot better for high temperatures. Basically the higher the alumina content of the clay, the better. It takes a lot of trial and error to find a good clay/sand mixture that works well. If you want to skip all that, one of the easiest and best performing ways to make a furnace is to just get a metal cylinder, line the inside with 3-6 inches of Kaowool then coat it with a layer of castable hot face like ITC 100. That stuff has a melting point of 2482°C and is used to reflect the heat of your furnace back into your crucible.
That is really good info!! cheers
It is also used to seal the fibres of the wool/insulation as they are slightly carcinogenic
ITC 100HT is way too expensive to use on its own, but this is very nearly correct. One should use a stabilizer on the refractory insulator to protect it from shock and slag, coat the stabilized refractory in satanite refractory cement to give it rigidity, and then coat the satanite in the 100HT. That stuff is like $75USD a pint and a pint is at least enough for 2-3 projects this size. I don't trust 100HT for structural support and will use a SS tray anywhere that it might get hit by slag. The 100HT is primarily desirable for heat up time reduction and heat retention. It reflects IR radiation when it gets to a high temp and increases in efficiency of reflection the hotter it gets up to its thermal limitations. I'm about to build a small propane forge with this method and an Aussie style adjustable self aspirated burner. If I'm wrong about anything I've learned from trusted sources in this, I'll edit the comment with what failed and how.
TL;DR: Satanite is $1/lb, 100HT is $40/lb. Use stabilizer on kaowool or carbon felt. Use satanite to give it physical durability and add a small additional insulation layer. Use 100HT only for its IR reflective properties so that it pays for itself after 200lbs of fuel are used.
@@LittleAussieRocketscheck my comment above. Kaowool or similar ceramic alumina refractory fiber insulation MUST be treated with a stabilizer to be safe to breath around and prevent damage to your insulation. It needs to be further protected with a cement. ITQ 100HT is incredibly expensive and should only be used for IR reflectivity because of that. Manufacturer instructions say the specific coating thickness for efficacy. I've heard it reduces fuel costs by about 20%. I don't know if time and twig savings make $75USD worth it, but using a purchased fuel source would justify it.
And this is what you do in your spare time? You need to find more spare time, and what would happen if you made it accelerated to 88 miles per hour. Great Scott !
I used to do a lot of freehand on pipe, especially the root pass. Tubing that small, I likely would have freehanded that, but it never hurts to practice or polish-up. If you want to weld that stainless tubing without a purge, and have less interference in your weld structure/appearance, keep your welding downhillish as you go around the tubing (same with welding any gaps for stainless). That is one hot stove (furnace) 🙂👍 Pretty cool 😏
Your furnace is brilliant!!!!
Once you get some appropriate furnace tongs to grip the crucible the pouring will be much safer.
You can use your lifting tong then switch to a pouring tong if you like.
I was so impressed with the termite mound as a furnace lining.
We used gannister and fire clays/bricks together with high end ceramics etc. I can assure you your lining stood up as well as anything we did.
You can do patch repairs but I expect you aren't going to be pushing it hard.
The use of the k type thermocouple was great. You can also get cheaper one shot dipping thermocouples but maybe that would cost more in the long run. Then theres IR but do you really need to go further.
When you consider safety gear a good thick leather metal workers apron is a real benefit and although the safety officer might complain wear your boots slip shod so you can flip them off instantly if metal gets in. Seen many a leg saved from cremation that way.
Shedding molten metal is better than holding it in your clothing.
Maybe you have looked on line for foundry supply companies for an idea of all the safety wear.
I would go with heavy leather gauntlets, leather apron, leather boot covers, leather boots, full face visor and fresh air flow.
Out of touch with the market and only really knew one tooling company in Australia.
Can I say water is the enemy in casting. On top of metal okay. Under metal run.
That vlog is the best thing I have seen in ages. Learnt so much good stuff watching you.
More power to your elbow. Many thanks. Please keep on with your brilliant work. Its inspiring.
Best comment. Water is scary, scary. Everything you said is on point. I'm using IR reflective ceramic coating in my forge builds, but using twigs as fuel, I don't think the cost is justified unless one had enough 100HT left over from another project where the fuel savings would pay for it.
Finally, I got to see the finished product! I've been waiting for it for so long. If I were in Australia, I would definitely buy one too 🤤! I'm also glad you like our machine! Keep on welding, you superstar!
Thanks 😊 I really have enjoyed using your machine. A huge thanks for supplying the welders for the giveaway. You guys are the best! ❤️
Now you can make some crucible tongs. Awesome idea. Turbo stove taken to the max!!!
I like your pet chicken. I have a dozen layers. They are all just so nice and clean.
Perhaps vibrant the insulation mixture when filling , I did using a needle gun on refactoring cement, and was surprised how much air was entrained in the mix , a most interesting video thank you .
Good work. We shared this video (and part 1) on our homemade tool forum this week 😎
Thank you very much 😊
I've made me a pair of tongs that is featured on my channel. However the design needs a lot of work.
Btw, whenever I was thinking about making my furnace. Never in a thousand years did I think that thin pieces of steel would stand up to the heat. The same with using a shop vac for air flow. I would have thought the plastic impeller would melt immediately. Shows how wrong I was. Impressive stuff.
It's a furnace and it's an amazing job.
Molten metal???
I say you have reached Rocket-Stove Mecca !!
You are a master when you continue to top yourself
Top of the craft spot is where you are at🧐🙏🏻
Amazing project and well put together content.
I’ve been looking into all of the different ways(electric, gas, oil, etc) to heat a foundry and this is unique.
Reminds me of what was done here in Australia when there was no fuel.
Plumb fire wood plasma straight into the combustion chamber.
🇦🇺🤜🏼🤛🏼🍀😎😂
Awesome work. I might make one of these for out at the block where I don't want to be carting and storing gas bottles, and we have tons of hardwood
Great stuff, a super charged rocket stove/furnace. It certainly works, you melted a charge of aluminium, that's brilliant! Yes it's called a furnace and you would use a 'pouring shank' to hold and pour the crucible.
wowowow! seriously awesome new tool! 💜 this adds fun new possibilities for melty-metal projects!
That hen was in the he way ❤😂
My great grandparents lived in a bush camp on North Straddie, and they made their wood-fired oven out of termite cement.
I have found perlite doesn't do so well mixed in - as it breaks down into dust with only a fraction of the original volume. Vermiculite falls apart as well, but doesn't seem to completely disintegrate as much. (On the other hand, for hydroponics I prefer perlite to vermiculite due to the open space).
Once again, informative, entertaining and impressive.
Thanks for explaining your pulse settings! Great video, great furnace!
I recommend using charcoal pellets they burn extremely hot especially with forced air.
A Foundry is the place where you melt and cast metal. A furnace is the item that you melt the metal in so you have made a Furnace to melt the metal in you Foundry. How would hardwood like Iron Bark go it burns a lot hotter than pine, that would be interesting to know. Great job I look forward to you videos.
Well done, sir! Brilliant!
Just come across your channel, this is super cool! I built a rocket stove forge for making knives, I used some scrap stainless tubing inside an old beer barrel, with forced air and enough wood I can get steel bright orange without much hassle, it's incredible!
I will second others on the naming. Once upon a time when I taught metal working, we had a forge which was for heating up metal for banging on, and the air/fuel ratio could be adjusted to be carburizing/neutral/reducing. The furnace was for melting aluminum and brass. Someday I would love to build an electric arc furnace and melt steel for pouring anvils. But for now, looking forward to that welder.
The only things that I would do to improve it is add some type of insulation between the burn chamber and the melting chamber. The other thing is to add a handle to the top of the melting chamber so you don't have to touch the top to swing it.
For heat, cheat. Grab a bag of coke. Use wood as primary heat source, add a handful of coke every now & then to boost.
As far as your tig welding goes, geez, for a guy who ‘apparently didn’t do much’ great job. I’m the undisputed King of Dip! Trust me, 🤣🤣🤣. Tig has got me bluffed 😂😂
Bloody nice final product, well done.
Thanks mate
I really like this design. What a cool option over expensive gas.
Some time ago I did a deep dive into cob ovens for pizza and baking. There are a range very specific ratio mixes of clay, sand and cellulose (straw, grass etc).
The old timers wound that termite mounds had these ratios perfect. No need for sifting sand for grain sizes, no need to experiment with your particular local clay to soil ratio, and no need to chop up straw and mix it in.
As for the straw, it's not really possible as a DIY to get it chopped small enough and mix it evenly. The termites have the cellulose particles in such small sizes and mixed perfectly.
The Clay to sand/dirt ratio is important as pure clay will shrink too much and not handle the heat cycles of uneven heats causing huge cracks.
The cellulose particles will burn out leaving tiny air pockets which will insulate.
I considered building a furnace with the combustion coming from a wood gasifier (fema or imbert design), but without the syngas cleaning and condensation part. The problem was in the suction to exhaust the gas in the burning chamber, fans would not work in the medium-long term in direct contact with the gas due to tar impregnation on the blades, it would have to be with a venturi effect and very strong to work (probably compressed air). Its design based directly on a Rocket-Stove is more cost-effective to do, even though the burning process has a lot of moisture from the wood/biomass due to the lack of a pre-drying chamber, the cold air doesn't help either.
You should maby add a venturi at the blower inlets so you get more static pressure. Or get a radial blower which has more airflow and is much quieter.
I think it is getting hotter than what your thermocouple is showing. Your stainless tube is only glowing dull red but the graphite crucible is glowing bright white. Could be that the material doesn't fully combust until after the thermocouple. That's good news or you'd melt the whole thing down.
Yes I have had the same thought.
I have some gray cast iron that I want to cut up and throw in there. If I can melt that, I'm up around the 1200°c.
@@LittleAussieRockets I'll bet three and five/thirty-seconds US dollars that you CAN melt cast iron with that. It's getting HOT. pretty impressive.
Very Nice build. I melted Ally with wood years back but have had people say it won't work. You showed the flaws in that!
If you want a lot of heat, make an inlet before the thermo couple and have a little oil going in there. You will push the numbers way higher with that.
That's a good idea 💡 👍
the problem with wood is the residual 10% moisture will cool your foundry when adding new fuel before heating it back up.
i read somewhere roughly, 1/3rd burn time it sucks heat out of the foundry, 1/3rd it burns of volatiles and the last 1/3rd its a pure coal fire.
The stove design continuous feed solves the biggest flaw of my setup below,
in my forced air brick foundry i could melt 4 kg aluminium in 40 minutes from cold start, but when i tried 1kg copper it took over 5 hours burning through 3 wheelbarrows of woodchips
I mean the people with the syphon nozzle sometimes use an air drier in their hose
At least with forges, typically you'd do the lining and a light fire, look at the cracks and then just put a thin slurry over them which will generally hold up ok. Ultimately though, refractory material is a 'wear item' which is getting replaced eventually and don't get too attached to it being there forever. In terms of the fuel, I think you're probably hitting the peak with the timber and nuts, if you throw some charcoal in there I can easily see that getting well into the 11-1200C.
Through summer you might want to chuck a mesh spark arrester on the top so it doesn't set the countryside on fire as much :)
Oh yeah- you can make crucible tongs easily enough with a rimmed crucible, for the larger types that don't, you'll want what's called a cradle, which is essentially a round loop and a clamp which comes in over the top to stop it tumbling out when turning sideways
When mixing the termite mound clay, try adding some loose fiberglass into the mix, We do this here in Scotland and it helps bond the materials when its dry and the results are much less cracking through use. love the temps you got on those palm nuts very good video as always
What you have made is a furnace when used to smelt but a hearth when used to heat metal for forging. The building or location is a foundry when casting metal and a Smithy or Forge when forging. Hope that helps.
That does help. Much appreciated. 👍
An electric leaf blower works great also
Hey if you used something like rockwool or ceramic wool as insulation in the foundry you could easily get the furnace up to 1200°C
If you add a small light weight flap check valve in the fuel shoot just above the air input then you might be able to get it to blow shut when you open the lid, and then when the pressure equalises with the lid on it will open and drop in the fuel
Thanks for share what you do master with this kind of furnance!
i´m very intresting in th next steps of.
An idea for your fuel feed tube, put a weighted gate on it to help stop loss of air flow when refilling.
I would love to see a screw feed hopper set up for adding the pine nuts to the burn chamber, like my bbq automatically feeding pellets to burn 🔥
I wonder if pre-heating the feed air by passing the tube through the exhaust might increase the temperature inside the furnace?
Great stuff! Exactly the design I was looking for planning my ground furnace upgrade! Right now it has the same hole firewood and crucible go to but I was thinking quite a lot to separate them:) Thanks!
Also, over here in NZ they have a type of tea tree call Manuka which is notorious for burning out pot-belly stoves. Maybe some of the Aussie tea tree timbers would have similar properties? The palm nuts would also have an advantage over the pine, in that they have a better surface area : volume ratio.
Are you..... Old Tonys brother!!! Nice to meet the rest of the family!!!!
If this old Tony had an Australian step cousin once removed, then maybe.😊
A fuel feed wheel would definitely serve decently as an airlock at the top of the fuel tube to avoid drastic temperature drops.
So wood burnt down to charcoal. The best quality fuel for smithing, low impurities, low ash, but has a short burn time.
But if you want to see moths being drawn away from halide lamps and into an open flame, coking coal can do that. It's dense enough that the high airflow won't blow it away.
Incredible work!
If you could find a way to use the exhaust to preheat the blast air a high percentage of that preheat temperature should get added to the furnace temp.
Very well made video great content like your tig helpers ,thanks for making it very talented man
What about a secondary air intake at the base of the chimney, where the flames start swirling? Ideally, that air would have been heated along your burn chamber.
30:11 Difference between Foundry and Forge...
A foundry melts metals in special furnaces to be cast into molds. A forge is a furnace or hearth where metals are heated prior to hammering them into shape. The act of forging is heating and hammering metal into a shape.
Whole thing is so cool 😳 980 degrees, you need some proper tongs though I could see the Au going everywhere
Great vid stuff the termites
Cheers
Did i say Au thats gold. Should be AL sorry anyhow i guess gold wouldn't need 980C
Cheers
Might add a burnt motor oil drip to it to bring up the temperature
Try putting valves on your air pipes so you can vary the flow to each pipe.
cool amazing job sir
Feed corn could be a good source of fuel aswell, I use it in my forge alot but it does stick together when its burning
put in a flow control for the air intake. it is running very oxygen rich. you probably only need about half that air flow but start by 10% reduction and test temps.
tyo much air cools it down faster than it can generate heat
Your thermostat should be in the crucible area there is More combustion happening after that first reading point. Is hotter in the chamber and you can always load char to boost temp. Run a blend of fuels.
Looked like the exhaust hole in the lid needs a spark arrester - it will have to be the same size as the lid and fairly tall as to not melt itself with the extreme heat [and sometimes fire] coming from the exhaust hole, might also function as a radiant heater as I assume it will glow red/orange from the heat
Very interesting indeed, my goal would be a 1200 Celsius for bronze and copper as well, butt you’ll figure that out too I suppose
look at getting a see through tig cup. itill help your welds greatly.
You don't actually need any extra air supply. The easiest way to get a hogh air volume draft is... adding a draft. On the exhaust side, add a 2m pipe, and it'll just suck air in from the bottom by itself. And really lots of air too.
I don't know if it'll equal the amount of air a forced air system delivers, but it's inexpensive and probably very effective.
Have you tried using a old diesel turbocharger. Taking a part of the exhaust and injecting into the intake. Using a high speed motor. You have to fab up a oil lub system . This should get the temperature up much higher.
Who knew nuts could melt metal.
Great Content my friend!
I'm will make an above ground pool(8500gal) heater. Trying to figure out the best way to transfer the heat from wood to the pool.
My plan is to fire a water filled 55gal steel drum with protruding angle iron nubs inside and out on bottom with a forced air rocket stove. Plan to use 2, 3 or 4 - 2.5ft length 3/4" copper pipe radiators coupled to a pvc manifold both sides of the drum , in the heated water drum to transfer the heat to the pool - using 1 1/4" pvc pipe with pool pump. High volume is key here, aprox 3000gph, looking to heat the output water to about 100f max or less.
Would it be better to heat the copper pipe in a direct flame?
I did play around with direct fire heating with my smokeless firepit but the cold coil copper extracted way to much heat from the fire causing terrible burn quality.
Thanks,
The lid blow outs may be due to moisture in the perlite and vermiculite not being able to evaporite quick enough due to the heat of the flame.
small thing I would consider is to insulate the fire box. If the heat doesn't radiate out to ambient air (glowing tube) then the hot air will maintain more energy. It would be cool if the foot lever for the lid also opened blow-off caps or actioned baffles to redirect the intake flow so that it wouldn't be blowing into the firebox when you're more than likely working right above it.
Oh and you could get more cfm from your vacuum if you take out the filter :)
Oh pt2: I looked into your vacuum and it may have a universal motor, which means you can wire up a 10000W SCR voltage regulator to throttle the motor speed
I actually had to reduce the airflow by venting off 1/3 of the air with a 3D printed part. The full power of the vacuum cleaner basically blew the fire out.
@@LittleAussieRockets ok cool so the scr would allow you to reduce motor speed instead of a blowoff tube
Crucible Tongs
Thanks mate 👍
"He's gone to light speed, sir"
"Then we will go to LUDICROUS speed!"
First video = subscribed
Greeting from across the ditch..
Thanks mate
I'd be interested to know how redgum might go as a fuel. With lots of airflow, it can get seriously hot.
Yall need a b2 berverly shear
I wonder how much pre heating the air would help. I guess a lot of the energy is going to heat the vacuum blast.
He went plaid !
The temp inside the furnace may have been higher than the burn tube. The burn tube is closer to cold intake air and the furnace is able to retain and gain more heat as it is lined with refractory. Nice to see your journey. I must restart my own.
If he had insulated the combustion tube, the temperature sensor would be in the correct position. Everything in the forge can be heated to the maximum temperature of the flame. The flame temperature at the entrance would therefore represent a maximum temperature.
Great point! I have some gray cast-iron that melts at around 1200'C That would be a test for it.
Is the temperature where you're measuring it, not lower than in the furnace itself?
Hola amigo, muy buen diseño, crees que este diseño es eficaz para una estufa? o me aconsejas otro diseño? saludos desde Argentina!
Slight problem termite mounds are a bit 'thin on the ground' in my part of the Northern Hemisphere - suggestions? Ant hills?
Having talked with other people about this, all the termites have done is separate the clay and soil to create a very pure and clean clay mixture. The only thing the termites have added is tiny amounts of organic matter. I think you could replicate this by adding wheat husk or wheat bran, which would burn out and create tiny air pockets increasing the insulation value of the clay.
Would it be possible to take the exhaust heat and run it through a heat exchanger to heat up the input air?
1810 Amen to That Great Vid as Always
7:35 My Mum had a cake tin shaped like that.
Great furnace mate, I'm just wondering how much heat ironbark would generate ? Just a thought.
No more candles?
Ironbark was ok but required a fair bit of processing to get it to run. It needed to be chopped up into fine kindling to produce any decent heat.
I don't have exact figures on the ironbark temperature ranges as I didn't have the thermometer installed when I was testing it.
Sounds like I'll need to revisit this maybe with or without candles. We'll see 😉
@@LittleAussieRocketsGood on ya mate. LOL
Vermiculite and perlite are prone to hold moisture.
Best to dry out before this type of application
what would be the damage if I got you to build me one of these little rippers?
Would you be able to fire it on coal?
How hot does it get when using charcoal?
I bought some charcoal so I'll be finding out soon
Watch Jason @ Mount Baker Mining and Minerals. For your pouring tools
Charcoal
Myfordboy here on TH-cam has some interesting stuff regarding casting and related info as well as a crucible holder design
how hot will Charcole go?
I use a 12v fan,with a speed controller,far more primitive than your setup ,melts aluminium though.IB
Put iron wood in there that will get it real hot .. my grand pa put iron wood in his fire box and it got so hot it cracked the fore box
I'm going to have to do an in-depth video where I run all different fuels through it.
I intended on doing that with this video. I just ran out of time.
I used a two-stroke leaf blower.....
wait so when you're welding that pipe you're not using anything as a filler? just fusing the stainless steel to itself?
Yes, that's correct. That's pretty standard practice for low pressure applications, particularly around the food grade industry, which is what I do most of my work in.
just a constructive criticism because ive watched your vids for years.
you need to pay more attention to your audio levels when editing the videos, no matter what software you use there should be a VU/sound meter somewhere that shows the audio level, you need to keep it at least mostly in the green and sometimes in the yellow and if it only hits red once or twice quickly that is perfect. i had my tv turned up all the way and half of what you said i still couldnt hear.
Good feed back thankyou
@@LittleAussieRockets all the software ive ever used allows you to edit the individual clips audio level to normalise them, in fact if you wana get tricky you can do some pretty advanced fades and stuff to normalise audio but if you just keep the audio mostly in the yellow without is going too far into the red {otherwise called clipping] the audio will pretty much be perfect for your audience. keep up the great work.