As a concrete worker I would suggest using a 10mm pea shingle instead of 20mm stone in your concrete and make your mix slightly wetter (a higher slump) using the micro fibres you used is still absolutely fine but you will need to vibrate your mix in the mould to get a full coverage and release all of the trapped pockets this can be done by tapping with a rubber mallet or a back massager if you don't mind it getting dirty. As for the letters cut them out of polystyrene or high impact foam and then it can be dissolved out using some acetone for that crisp look
doing something similar very soon and am amazed that i was suggested this. I bought my lettering from a craft store and will be making a ~1cubic foot cube, letting it cure for like a month before i unwrap, then filling the letters with a colored caulk. I love the idea of transferring the letters to foam and dissolving them out.
Yeah I was going to say that, I'm in school for engineering, and I was like... uh just use concrete with a higher slump. My recommendation also would be to put the block in water if possible for as long as possible after it sets, soaking it in water helps the concrete become stronger once it's shape has set, so if he just let it set in say a 5gal bucket of water for a month that thing would be very strong. I agree with the polystyrene idea though that is a very good idea.
“life time” I see it as a bit ambitious. My grandfather had made planters that started to burst and crack and crumble with time and frost (France). 35 or 40 years old
I watched a guy on YT use a Sawzall without a blade to get the air bubbles out of his concrete. His turned out crisp and clean without any air bubbles.
When it comes to vibrating your mold to release air bubbles, a great DIY method that can work for a lot of hobbyists would be to use a reciprocating saw or a sawzall with the blade removed. Press the shoe against your mold and squeeze the trigger. The reciprocating saw can create much more intense vibrations vs an orbital sander. Diesel fuel also works as a good mold release agent. Its oily texture and low viscosity allow it to be sprayed on using a squirt bottle or garden chemical sprayer. This helps ensure a good even coat. I have poured concrete foundations, sidewalks, pads, stairs, and various other things. Often we used diesel fuel as an inexpensive, readily available mold release. Thank you for your time putting these types of videos together.
i work with concrete molds i do ornamental plastering for a living . your best bet for a nice finish is to give you mold a coat of raw cement & water mix to a slurry and coat your mold with a large paint brush then fill away your mix was a small bit too stiff. great videos
My final year project whilst doing a degree in civil engineering was investigating/evaluating different board products and release agents. The results were very mixed, with the best outcome when using Phenolic Resin Treated plywood + release agent. My advice for crisp lettering would be to add a rich cement mortar mix as a bottom layer, and then introduce concrete, vibrated in, and some reinforcement half way up. When you strike the shuttering, immediately 'rub in' cement grout to any voids. An excellent video - nothing wrong with your methodology in making the moulds. Most enjoyable watching.
When I cast garden statuary, I mix a slurry of cement and sand (about like a heavy cream) that I roll around in the mold until all surfaces are coated before putting in concrete (mixed with pea gravel (not large stone aggregate) and any reinforcing wire. I agree that the 7° draft won't be enough for those deep letters and would do more shallow letters or greater draft. I use cooking oil (Pam) in a spray can as release but I'm usually using rubber molds. I'd suggest waxing the wooden letters with a paste wax before applying your release. Thanks for showing your concrete casting work on TH-cam.
Don't know that I mentioned acetone but that'd be another option in your casting. I did a whole walkway by drawing shapes on 4' by 8' by2" sheets of styrofoam, cutting them out (but not removing them) then staking the panels to the ground. I then pulled out one piece at a time and poured concrete into the space. I ended up with an intricate walkway of concrete pieces with a meandering divider of styrofoam which I "removed" by pouring in acetone to melt the styrofoam. (This process could also be used to do your markers where you could use styrofoam letters and melt them out with acetone.)
One thought: If you have a 3D printer at hand, it's easy to print the characters with it. I would make holes for threaded inserts (in the back) so that they can be easily removed with a screw and reused. I would choose PETG as the material - concrete can get warm during curing (heat of hydration).
Expanding on this: Why remove them at all. Pick a good contrast color and print the letters with the intention of leaving them. If you want a reveal use a trim router.
I'd recommend you apply a very fine face coat first, with finer aggregate before vibrating. Typically this is done with a sprayer, but can be done by hand. Then backfill with you more traditional mix. Secondly, superplasticiser will significantly increase the flowability of the mix without adding additional water (which weakens the mix), this will give you a stronger concrete but alsp help reduce air bubbles.
@@travisash8180Using Fairy Liquid in concrete is a bad idea. The foaming agent entrains a lot of air so has a plasticising effect by adding air not by pushing cement particles apart, although the main problem is that the detergent interferes with the formation of the calcium aluminate hydrates and calcium silicate hydrates. Far better just to use a proper plasticiser/superplasticiser.
@@vinced2514 I suspect there's many things that could be called self levelling concrete and occasionally it's used interchangeably with self levelling compound and there are many different applications. Some of those will be limited in depth (because some SL concrete doesn't contain much, if any aggregate and so is relying on a substrate underneath it for most of its strength). As it's a grey area, I'd look at the manufacturers recommendations for usage. My personal preference, when casting concrete countertops is to design the mix myself (CCI - Concrete Countertop Institute has all the info you need for this) based on what's locally available and adding the superplasticiser myself.
I'm impressed with your finish product. I cast a lot of concrete sleepers and I used the cheapest spray cooking oil as the release agent and it worked very well, and being a spray bottle it was quick to apply.
Excellent advice on getting the bubbles out. Personally I use a reciprocating saw without the blade in it. Run it along your forms and it works pretty well. You can always borrow your wife's personal massager also.
I'm assuming by now someone has mentioned that a Sawzall ® is a common Trade name of the reciprocating saw? Like how everyone calls facial tissue Kleenex® and most all of us call cotton swabs Q-tips®!* Just throwing that bit of info out there. Help clear up any confusion. Or create more, IDK. 🤷🤷♀️🤷♂️😊 *This info is America based. These items may have different common Trade names/different common names in your part of the world 🌍👍🤟
Excellent! I use a reciprocating saw without the blade to vibrate the forms on sidewalks. They turn out great. Use a reciprocating (DEWALT, Milwaukee, Porter Cable) saw. Place the shoe of the saw against the form. Squeeze the trigger, the shaft minus the blade moves back and forth causing waves in the concrete. If you you have a variable or orbital speed option you can increase or change the action to suit your needs. I usually move it around the form watching the waves in the concrete. It helps level the concrete as well. Remember, don’t vibrate to much. It will cause your aggregate to sink and weaken your project. The purpose and what you are looking for is bringing the cream to edges and top, eliminating the air pockets.
I think your concrete could have been a little wetter and runnier. I use my battery-powered Sawzall (without the blade) to remove the bubbles. Works great. The beveled edges were a nice touch too! Your projects were good ideas! Cheers.
I think the consistence is about right, especially for the power for the poker! There would certainly be full compaction with this consistence/poker combination. The issue is the surface tension of the entrapped air against the form. Interestingly, the less permeable the form, the more likely the appearance of blow-holes. Wax sealer on ply or controlled permeability formwork liner can give wonderful results.
Additionally if you give the wood a wash with diesel with a paint brush the wood and letters you will find that the concrete will not stick to the wood. Old farmers tip fram my dad.
The least water that you can add and vibrate the fines around the aggregate will maintain the most strength of the concrete. The wetter the concrete the lower the strength and more likely to crack.
Neither my skills nor my equipment are anything close to yours. But I do enjoy watching your videos and see how many of your tips I can retain and possibly use later on.
A lot of work, specially the handmade letters. I know, I'm a signwriter. Very well made. As the name says, you did it properly, or applied your knowledge properly so next time a few tweaks will be needed
20 years ago I bought a fitness machine that worked (well…) by you standing on it doing some exercise and it shaking the platform you stood on. Works perfectly for getting those bubbles out, I guess. 😊
A lot of concreters use diesel to spray their formwork with. Good release agent and in the case of metal forms or moulds, helps prevent corrosion. Nice work. 👍
Great job! You are right about thinner letters and numbers, plus, they would leave less of a void for water/snow to gather during freeze/thaw cycles outdoors.
Depending on the application, you could also fill the letters with either resin or a different color of concrete to make them stand out well. You don't have to fill them in fully, so you could get a measure of "3d" still. Use a thinner concrete or resin that will self-level.
This looms like a fun project. MANY steps to create a one'off mold, but what a nice result! I have used parrafin to lubricate long screws that hold deck boards, which w/o it were twisting in two in the treated joists. I wondered if dipping the letters in melted candle wax would work well to create a good mold-release surface on them. It could work for all of it, if you made the form from bare wood, then heated it some, and brushed on melted parrafin. The mold would have to be just above the melting poi t oof the parrafin, I would think. Anyway, it could crwatw a frm surfacs suitable for multiple uses. Thank you for sharing so clearly the way you made this mold, and the explanation of why you performed each step the way you did. Nicely done.
Fiber reinforced self leveling compound will just be ok to that depth, give a much finer and crisper edge and be more likely to be bubble free. It can also be mixed by drill and paddle and pours in the mould.
Really enjoying your channel. I've used disc sanders hundreds of times, and yet never took rim speed into account as it relates to sanding speed. Top notch content.
This has given me an idea. I've only just bought myself a compressor and in the middle of setting myself up with a couple nail/staple guns and I think my next two purchases will be a band/scroll saw and a big vibrator for concrete. Late father-in-law made his own bricks for the front of the property many years ago and I've been watching some other videos on making things with concrete which has given me thoughts on projects for the garden. Thanks for another of your amazing videos.
for the lettering finishing. could fill up those letters with melted brass or similar. you can just polish them. to make sure the brass doesn't come out, drill in some steel screws. so when the brass gets around the screw heads It will lock the poured brass in place
I use an old cheap orbital sander to remove the bubbles. I glued a piece of non-slip toolbox liner to the pad for extra grip...it works very well for all.but the largest moulds.
i make concrete plaques and will be sending a cease and desist lol just kidding very cool, interesting to see your method, with my plaques, the design protrudes out instead of being engraved inwards. Concrete Plaques NI - if you want want to see them. Keep up the good work, love the channel 👍
Put a plasticizer in the mix before you pour and it will make the concrete run like water. Okay, maybe not water but it does make it flow. Then, when you vibrate, the concrete will easily get into all the little nooks and crannies and the bubbles will also have a better chance of releasing.
When I used rein fibres rendering my koi pond, I ran over the surface with a blowtorch after it dried to remove any fibres that were sticking out so the fish didn’t damage themselves. Worked a treat.
Alternate lettering that works perfectly for these types of concrete signs are foam letters used by kids to learn the alphabet. They are available in a variety of sizes and fonts ….. (but not as varied as your use of computer printed font followed by cutting each letter out.). The foam letters are compliant enough that very little damage is done to the concrete during de-molding. I E6000 glue to attach each reversed letter to the bottom of the mold. After de-molding, my mold was in good enough shape that I could have used it again. My end product was a beautiful grave marker for my beloved dog, Patches.
A few years ago I cast a large number of faux stones (about 800 in all) in plastic molds. To help remove bubbles and settle the concrete mix, I took an old metal shelf unit, and attached my hand held saber saw to the underside of it. (with the blade removed) Turning on the saw provided ample vibration, settling the concrete is a matter of seconds.The shelf unit was large enough that I could fill a mold, and have 2-3 previously filled molds continuing to settle at the same time. I hope this idea is helpful to someone.
As a relatively new subscriber, I just want to say , A Big Thank You. Although I'm quite confident at most D.I.Y. on occasion there has been the odd forgot about aspect of a project, your videos have invariably shown a comprehensive how-to-do error free way. Love your channel, so, Thanks again👍. Proper is as Proper does.
Another tip. When making small concrete objects like this use pea ballast. The aggregate being smaller is better for smaller castings. When we used to cast cills in situ we had one shot and they used to come out perfect. Using 20mm ballast the aggregate is just too big.
16:03 I love the custom music with voice over bit 😆 At first I thought you found the perfect track and then after the 3-4th comment I realized, "oh he's actually done this all himself! Now that's Proper DIY!"
We've made boundary markers for years on the farm here in upstate New York doing something similar. We just made a new one with the twist that we 3D print the lettering now and put mold-release on the letters (vaseline jelly). Cheers!
If you wrap them the letters with clingfilm, it will allow the letter forms to be easily removed from the clingfilm before peeling the clingfilm from the concrete. Also, for simplicity, use children's wooden letter and number sets, unless you want serif letters. If you're going to reuse the letters, drill and tap (wood) or glue in (plastic) threads into the letters for removal, fill them with grub screws topped with putty during forming. One thing I've done before, for a better finish, is to build a bottomless inner form out of 1mm sheet metal that is 2cm shorter and 2cm narrower on each edge than your large form. Use cement to fill the first 2cm of the main form, then hang the inner metal form inside the main form, keeping the spacing even on all sides. Fill the 2cm space between the inner form and the main form with cement before filling the remaining space with concrete. When the form is filled, remove the metal form and use your vibrating tool to bind the concrete to the cement and to remove the bubbles before setting. This will prevent the concrete aggregates from marring the surface or filling the voids in the letters. Also, concrete takes 11 days per cm of thickness to fully cure. You can also do lines and flourishes, and if you want the words to require little to no maintenance, fill them with silicone. Excellent video, its very nearly as easy as you made it look (unless you're me and can't cut a line straight)!!!
The air voids actually increase the ability of the concrete to withstand the temperature variations in exterior use. We intentionally add “air” (essentially a soda that creates bubbles ) in exterior mixes to increase strength and decrease the air in interior slab pours to decrease bubbles in the finish process of a hard troweled floor. You can always sack the finish with cement while green to fill the exterior small pin holes from the air.
Nice work, looks good. I've made concrete signs before but went at it a bit differently. I router a piece of wood with the words making a negative mold, spray with release agent, install some sides then pour in some plaster paris. Take that and use it as the bottom in my concrete mold with more release agent then pour concrete. Also I just use a palm sander as a vibrator on the outside of the box......kind of the same I guess.
Very interesting as usual. If you make any more I'd suggest compacting the concert as I did and I'm sure you did in days gone by when making concert test cubes. Fill a third at a time and use a 25mm square tamper as your moulds are a similar height to the test cubes. That method was always very successful in removing air bubbles from the sides and interior as could be seen when they were crushed. Always look forward to your weekly video with expectation. Regards Alan 6:47
Great stuff! Try a damp mix similar to the way concrete blocks are made. I used to make ornamental precast stone for buildings in NYC. We would make a shell of damp mix and fill it with wet mix. The surface look more authentic this way.
I find using childrens plastic magnetic fridge letters work well. Ideal for small garden signs. I understand its not the same and as satisfying as making your own letters.
I make concrete molds for a living you did everything spot on except pull the piece the next day all imperfections can be filled with a thin slurry and rubbed to a uniform finish mild acid wash also great presentation though 👍
Back when i did building construction in school (1985-ish) we used to make up a paint on slurry of concrete powder, fine sand and water. First we'd oil the mould then paint all the surfaces of the mould with the slurry, then half fill, add reinforcement, then fill up to the top. Back then our only option was as you rightly pointed out, hit it lots with a hammer 🤪🤪 and then strike off. Lastly tap in any required strips of beading for a drip channel ( window sills etc) Made them pretty much perfectly smooth 👍🇮🇪👍🇮🇪👍🇮🇪👍🇮🇪👍
The air gaps look good to me but it's a personal thing. Regarding the reinforcement fibres, if you blast them with a heat gun they shrivel to nothing and the concrete no longer looks 'hairy'. It's a weirdly satisfying job. The ones I have used in the past have been some sort of plastic and not actually glass fibres, hence the heat gun shrivelling them up. On the vibration point, I woder if anybosy has tried a multitool as they are quite violent at the business end. I haven't tried but was intending to on my next pour, whenever that may be. Anyway, super fun projects and thanks for the vt.
Great video! Love your saying about you live and you learn. I learned that using a concrete sprayer to do the first face coat gets you near perfectly smooth surfaces.
I use 2 inch or 5cm pink foam board insulation to make my molds. I use a 4' x 4' or 120cm x 120cm CNC router to in the lettering and or shapes into the foam. I've always brushed on a mold release and let it dry before pouring the concrete into the mold. I need to try your mineral oil as it would be less expansive. I use the bag concrete and use a sifter to remove the larger pebbles that are in the concrete. I would mix my own concrete, but I haven't run into an issue yet to persuade me to change. I did have a mixer but really didn't need it, so I got rid of it because I never see me make large runs of anything concrete. I learned hand batching in a plastic concrete tub is much better and cleanup is faster. I have a vibrating table and some of my projects still end up with bubbles. I liked your video as it shows the craftsman ship you have.
Love the concept ... great result. You could fill the letter voids with bright day glo epoxy resin ... really make them pop rather than just using the cut in. 3D print the letters in PLA and then just hit them with a heat gun at 90C and they will soften up enough to come out easily with no damage to the surrounding concrete ... Also a slight draft on the molds and you may get the concrete to release without pulling apart the mold.
To reduce the voids from bubbles I would try adding plasticizer to your concrete mix. It makes the mix behave like you added more water without adding more water. The bubbles will float to the top much easier.
I've used the fibres in rending mix, I got better distribution adding them to water first in the mixer until they had evenly spread out then add the dry ingredients, adding them later they seem to clump together.
If you use granolithic concrete ballast rather than the standard stuff you get from the builders merchant, you'll find the detail comes out a lot cleaner. It goes from dust to 5mm rather than to 20mm. Also you can fill any small voids left by the bubbles with slurry of straight cement.
I’m a lettering artist and I would still probably just get my letters lasercut from either foam or mdf for this. Ideally something that doesn’t absorb moisture. Smaller aggregate too and a bit lighter reinforcing metal. You’re not making a lintel afterall. But good stuff. Your videos are great.
I saw TH-cam video of some guy making concrete thombstone for people who can't afford granite tombstones for their dead family members. that was around 10 years ago. used mostly similar technique, but he made the letter using hard sponge material, which can hold shape, but still flexible enough to be removed easily.
Try Cementall, it is the most expensive but cures really hard and smooth as glass as it does not require an aggregate. Also, try raised letters instead of recessed. To achieve raised letters/designs on your final product you need to recess them into your mold and also make sure they are backwards so they reflect on the final product properly. I use foam board and a Shaper Origin to route out the design in the foam, a router or traditional cnc would work as well. You can build a standard mold around the foam or router/cut the mold into the foam. These are really fun projects.
One thing you could try is buying silicone mould with letters (or even making your own, but that is another project on its own), then casting them from paraffin wax mixed with sand. They will be almost rock hard, yet easy to remove from concrete with heat gun. You will be able to reuse sand and wax too, if you heat it above container to drip out (wax may need some replenishing).
Great vid thanks. I have an elephant mould that has lots of curves. I was advised, when i bought it, to make it sloppy. I've had them outside for 20 years and they still look good.
Find a paint mixer such as used in paint stores, with a solid top. Cover the top with cork, add straps to hold the forms, and put the top the same height as your work surface. Put in a large can of paint, or water filled can, and shake away. You may, possibly, have to build higher sides to the forms, or cover them tightly when shaking.
I used 6mm laser cut MDF with no bevel as had them laying around the worked quite well, and you can soak them to get them out in a more gentle exit procedure. I also used varnish and WD40 as a releasing agent because that's what I had. For the molds I kept some of the better bits of old kitchen i had replaced which are perfect. There's always tons of that down the recycling centre, have a word with the staff. If you want screw you sign to a wall as i did a couple of dowels to go through will suffice for the screw holes or in bed something in the concrete like a hanger or hooks, or some bolts if you are think of a wooden plinth or similar
I like to use my oscillating tool to get rid of bubbles in cement. If you are pouring into a form, leave an extra lip large enough to set the oscillator on and clamp it to.
for the vibration portion and removing bubbles, perhaps consider using the table saw table. Fix the boxes to the table, turn on the saw, and let the vibration from that do the trick.
Yes..As Alastair below comments, I too thought your mix was too stiff for bubbles to rise through. I would use a very wet mix for the first pour then before it goes off a stiffer mix can be added for the bulk of it. Also, if using an aggregate you need a small grain in that first pour wet mix. This should give you a fine smooth surface finish with a more rugged matrix underneath. Of course it is all experiment to get the best result.
Interesting project! I would use a cement plasticiser on a job like this, to improve the slump without adding more water... I find it significantly reduces voids. Maybe try some cement dyes as well? Great that you kept your moulds reusable, to play with again!
For the size of these works you don't need any reinforcement. Fibre is detrimental to the finish of exposed concrete. If you're concerned about freeze-thaw cycles, 10 gauge wire is more than sufficient. The concrete mix is of more concern. Small pieces with fine details need smaller aggregates. Exposed to weather they also need a higher cement content and 6% air entrainment. The pencil vibrator may have contributed to the bugholes as it has a tendency to actually create bubbles on the surface resulting in an Aero bar concrete. I made cast concrete gutter slabs for my mum's garden patio 12 years ago. Each used a 30kg bag of premixed 27.5MPa (4,000 lb) concrete mix with a squirt of Fiery liquid to create the micro air bubbles. The form was made from 26 gauge galvanized sheet metal. There was no reinforcement. Each gutter was about 45cm long and 5cm thick thinning to 3cm. I used a hammer ( I tried an orbital sander for the vibration, but it was ineffective). The piece's were removed from the forms after 24 hours. One (of 13) broke because I was clumsy. The remainder are still in place without damage beyond scrapes and chips from the spade done to remove ice and snow. That 12 Canadian winters!
I think they came out great. What if you used a cheap HDPE cutting board for the letters? Be a bit more money, but they'd probably slide right out and you wouldn't have to sand or varnish them. You could pin nail them to the particle board to hold them in place.
This is the first guy that is watchable without being patronising condescending or American. I have my own property maintance company and don't want to be lectured to, like I'm an idiot. This guy is spot on with the level of information, his cheery approach and his obvious competence and great ideas. Trust me you never ever know it all, however long you've been a tradie and finding a TH-camr that is watchable and gives you good tips is RARE!
An interesting experiment Stuart, they came out pretty well I think, thanks for taking the time to make and share this with us all, your editing and use of different music etc was really good on this one - more great content - Cheers !
Keep the water content in spec and add a wetting agent and the slump will increase greatly (without loss of strength) allowing the escape of trapped air with vibrating. Quicken cure by wrapping in black plastic (to keep moisture content up) and put some heat into it, like in the sun>
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As a concrete worker I would suggest using a 10mm pea shingle instead of 20mm stone in your concrete and make your mix slightly wetter (a higher slump) using the micro fibres you used is still absolutely fine but you will need to vibrate your mix in the mould to get a full coverage and release all of the trapped pockets this can be done by tapping with a rubber mallet or a back massager if you don't mind it getting dirty. As for the letters cut them out of polystyrene or high impact foam and then it can be dissolved out using some acetone for that crisp look
doing something similar very soon and am amazed that i was suggested this. I bought my lettering from a craft store and will be making a ~1cubic foot cube, letting it cure for like a month before i unwrap, then filling the letters with a colored caulk. I love the idea of transferring the letters to foam and dissolving them out.
I was going to say that the concrete still looked pretty green for a week old. Maybe let it cure a bit longer.
Yeah I was going to say that, I'm in school for engineering, and I was like... uh just use concrete with a higher slump. My recommendation also would be to put the block in water if possible for as long as possible after it sets, soaking it in water helps the concrete become stronger once it's shape has set, so if he just let it set in say a 5gal bucket of water for a month that thing would be very strong. I agree with the polystyrene idea though that is a very good idea.
“life time” I see it as a bit ambitious.
My grandfather had made planters that started to burst and crack and crumble with time and frost (France). 35 or 40 years old
I watched a guy on YT use a Sawzall without a blade to get the air bubbles out of his concrete. His turned out crisp and clean without any air bubbles.
When it comes to vibrating your mold to release air bubbles, a great DIY method that can work for a lot of hobbyists would be to use a reciprocating saw or a sawzall with the blade removed. Press the shoe against your mold and squeeze the trigger. The reciprocating saw can create much more intense vibrations vs an orbital sander. Diesel fuel also works as a good mold release agent. Its oily texture and low viscosity allow it to be sprayed on using a squirt bottle or garden chemical sprayer. This helps ensure a good even coat. I have poured concrete foundations, sidewalks, pads, stairs, and various other things. Often we used diesel fuel as an inexpensive, readily available mold release. Thank you for your time putting these types of videos together.
i work with concrete molds i do ornamental plastering for a living . your best bet for a nice finish is to give you mold a coat of raw cement & water mix to a slurry and coat your mold with a large paint brush then fill away your mix was a small bit too stiff. great videos
I have no idea why this was recommended to me, but this was a fun watch. I love how helpful and positive the comments are below
My final year project whilst doing a degree in civil engineering was investigating/evaluating different board products and release agents.
The results were very mixed, with the best outcome when using Phenolic Resin Treated plywood + release agent.
My advice for crisp lettering would be to add a rich cement mortar mix as a bottom layer, and then introduce concrete, vibrated in, and some reinforcement half way up.
When you strike the shuttering, immediately 'rub in' cement grout to any voids.
An excellent video - nothing wrong with your methodology in making the moulds. Most enjoyable watching.
When I cast garden statuary, I mix a slurry of cement and sand (about like a heavy cream) that I roll around in the mold until all surfaces are coated before putting in concrete (mixed with pea gravel (not large stone aggregate) and any reinforcing wire. I agree that the 7° draft won't be enough for those deep letters and would do more shallow letters or greater draft. I use cooking oil (Pam) in a spray can as release but I'm usually using rubber molds. I'd suggest waxing the wooden letters with a paste wax before applying your release. Thanks for showing your concrete casting work on TH-cam.
The slurry idea is very good. I need to try the acetone idea. Also sounds very useful.
Don't know that I mentioned acetone but that'd be another option in your casting. I did a whole walkway by drawing shapes on 4' by 8' by2" sheets of styrofoam, cutting them out (but not removing them) then staking the panels to the ground. I then pulled out one piece at a time and poured concrete into the space. I ended up with an intricate walkway of concrete pieces with a meandering divider of styrofoam which I "removed" by pouring in acetone to melt the styrofoam. (This process could also be used to do your markers where you could use styrofoam letters and melt them out with acetone.)
One thought: If you have a 3D printer at hand, it's easy to print the characters with it. I would make holes for threaded inserts (in the back) so that they can be easily removed with a screw and reused. I would choose PETG as the material - concrete can get warm during curing (heat of hydration).
I would also make the sides angle backwards slightly instead of being vertical to make them easier to remove.
@@mantis1au Stuart did, if i got it correctly.
@@mantis1au He already did that. Were you not paying attention?
@@piggybakkers Obviously not, I thought he cut and sanded them vertical. Looking back, he didn't.
Expanding on this: Why remove them at all. Pick a good contrast color and print the letters with the intention of leaving them. If you want a reveal use a trim router.
I'd recommend you apply a very fine face coat first, with finer aggregate before vibrating. Typically this is done with a sprayer, but can be done by hand. Then backfill with you more traditional mix.
Secondly, superplasticiser will significantly increase the flowability of the mix without adding additional water (which weakens the mix), this will give you a stronger concrete but alsp help reduce air bubbles.
You say a superplasticiser.
Could he use mild green fairy liquid instead ?
@@travisash8180Using Fairy Liquid in concrete is a bad idea. The foaming agent entrains a lot of air so has a plasticising effect by adding air not by pushing cement particles apart, although the main problem is that the detergent interferes with the formation of the calcium aluminate hydrates and calcium silicate hydrates. Far better just to use a proper plasticiser/superplasticiser.
What about PVA glue?@@Cannondale4321
BigDDunc - How about "self leveling" concrete? Or is that just regular concrete with superplasticiser already added?
@@vinced2514 I suspect there's many things that could be called self levelling concrete and occasionally it's used interchangeably with self levelling compound and there are many different applications. Some of those will be limited in depth (because some SL concrete doesn't contain much, if any aggregate and so is relying on a substrate underneath it for most of its strength).
As it's a grey area, I'd look at the manufacturers recommendations for usage.
My personal preference, when casting concrete countertops is to design the mix myself (CCI - Concrete Countertop Institute has all the info you need for this) based on what's locally available and adding the superplasticiser myself.
I'm impressed with your finish product. I cast a lot of concrete sleepers and I used the cheapest spray cooking oil as the release agent and it worked very well, and being a spray bottle it was quick to apply.
Excellent advice on getting the bubbles out. Personally I use a reciprocating saw without the blade in it. Run it along your forms and it works pretty well. You can always borrow your wife's personal massager also.
came for this. (phrasing?) sawzall or jig saw with no blade was my go to in the past, seemed to work fine for making stepping stones
I'm assuming by now someone has mentioned that a Sawzall ® is a common Trade name of the reciprocating saw? Like how everyone calls facial tissue Kleenex® and most all of us call cotton swabs Q-tips®!* Just throwing that bit of info out there. Help clear up any confusion. Or create more, IDK. 🤷🤷♀️🤷♂️😊
*This info is America based. These items may have different common Trade names/different common names in your part of the world 🌍👍🤟
@@jeremykendall-thomas7300 no because more and more people are using the recip term.
@@jeremykendall-thomas7300who gives a shit
Excellent! I use a reciprocating saw without the blade to vibrate the forms on sidewalks. They turn out great. Use a reciprocating (DEWALT, Milwaukee, Porter Cable) saw. Place the shoe of the saw against the form. Squeeze the trigger, the shaft minus the blade moves back and forth causing waves in the concrete. If you you have a variable or orbital speed option you can increase or change the action to suit your needs. I usually move it around the form watching the waves in the concrete. It helps level the concrete as well. Remember, don’t vibrate to much. It will cause your aggregate to sink and weaken your project. The purpose and what you are looking for is bringing the cream to edges and top, eliminating the air pockets.
Instructions unclear. Guy stuck Sawzall into concrete and now it don't work no more. Hahaha :P
@@lucash1980Read my reply again.
I think your concrete could have been a little wetter and runnier. I use my battery-powered Sawzall (without the blade) to remove the bubbles. Works great. The beveled edges were a nice touch too! Your projects were good ideas! Cheers.
I think the consistence is about right, especially for the power for the poker! There would certainly be full compaction with this consistence/poker combination. The issue is the surface tension of the entrapped air against the form. Interestingly, the less permeable the form, the more likely the appearance of blow-holes. Wax sealer on ply or controlled permeability formwork liner can give wonderful results.
Additionally if you give the wood a wash with diesel with a paint brush the wood and letters you will find that the concrete will not stick to the wood. Old farmers tip fram my dad.
The least water that you can add and vibrate the fines around the aggregate will maintain the most strength of the concrete. The wetter the concrete the lower the strength and more likely to crack.
Neither my skills nor my equipment are anything close to yours. But I do enjoy watching your videos and see how many of your tips I can retain and possibly use later on.
An interesting slant on what you can make with concrete Stuart, thanks for the video.👍👍
Slant?
Excellent comments from Concrete workers here.
Thank you all.
A lot of work, specially the handmade letters. I know, I'm a signwriter. Very well made. As the name says, you did it properly, or applied your knowledge properly so next time a few tweaks will be needed
20 years ago I bought a fitness machine that worked (well…) by you standing on it doing some exercise and it shaking the platform you stood on. Works perfectly for getting those bubbles out, I guess. 😊
A lot of concreters use diesel to spray their formwork with. Good release agent and in the case of metal forms or moulds, helps prevent corrosion. Nice work. 👍
Great job! You are right about thinner letters and numbers, plus, they would leave less of a void for water/snow to gather during freeze/thaw cycles outdoors.
Great video! Lots of old railway signs (for stations) used to be made like this and rail companies had their own casting yards. I must give it a go!
When I do concrete moulds for mow edging’s I simply paint the wood with vegetable oil, releases beautifully 👍 excellent as always Stuart 👍
Or you can use a diesel wash. A tip from my farmer dad.
Depending on the application, you could also fill the letters with either resin or a different color of concrete to make them stand out well. You don't have to fill them in fully, so you could get a measure of "3d" still. Use a thinner concrete or resin that will self-level.
I like the idea of using clear plastic letters , and set in concrete with LED Backlighting to enhance the whole project.
This looms like a fun project. MANY steps to create a one'off mold, but what a nice result!
I have used parrafin to lubricate long screws that hold deck boards, which w/o it were twisting in two in the treated joists. I wondered if dipping the letters in melted candle wax would work well to create a good mold-release surface on them. It could work for all of it, if you made the form from bare wood, then heated it some, and brushed on melted parrafin. The mold would have to be just above the melting poi t oof the parrafin, I would think. Anyway, it could crwatw a frm surfacs suitable for multiple uses.
Thank you for sharing so clearly the way you made this mold, and the explanation of why you performed each step the way you did. Nicely done.
What a great video, I watched most if not all of yours and I don’t think you’ve ever done a bad one. It’s inspired me to have a go!!!
Cool video. The negative letters has the nice effect of minimizing any bubbles visually.
Fiber reinforced self leveling compound will just be ok to that depth, give a much finer and crisper edge and be more likely to be bubble free. It can also be mixed by drill and paddle and pours in the mould.
Maybe you could part fill the lettering with a contrasting coloured epoxy to stop the concrete eroding when rain sits in there thru the winter
i was thinking the same, the voids will degrade - filling them with epoxy would be a great idea.
I've cut acrylic letters and just left them in the pour. They've been there for years now and still look great.
Super build, not only make the numbers and letters shallower but also increase the angle too. But super tutor
ial
Really enjoying your channel. I've used disc sanders hundreds of times, and yet never took rim speed into account as it relates to sanding speed. Top notch content.
Watchin from 3357 miles away. Proper job 👍
I have used my mains-powered drill with hammer function with just a large nail or screw in the chuck to knock the bubbles out.
Flippin’ heck, I’ve got enough damn projects to do, now it turns out there’s another to add to the list 😂
Great video fella
Sawzall reciprocating saw without a blade does a bang up job
This has given me an idea. I've only just bought myself a compressor and in the middle of setting myself up with a couple nail/staple guns and I think my next two purchases will be a band/scroll saw and a big vibrator for concrete. Late father-in-law made his own bricks for the front of the property many years ago and I've been watching some other videos on making things with concrete which has given me thoughts on projects for the garden.
Thanks for another of your amazing videos.
Great vid, Must give it a go. Maybe an oscillating multi-tool might be good for small projects to remove air bubbles...
for the lettering finishing. could fill up those letters with melted brass or similar. you can just polish them. to make sure the brass doesn't come out, drill in some steel screws. so when the brass gets around the screw heads It will lock the poured brass in place
Although I may not do this, I enjoy your videos because in the process I see things that may help in other projects.
Your results are pretty good but if you change your sand out for play sand and make your mix a bit wetter you will get better results. Hope this helps
It was fun watching you do that Stuart. Unfortunately I have too many ordinary things to fix, repair, maintain to do the crafty creative stuff.
I use an old cheap orbital sander to remove the bubbles. I glued a piece of non-slip toolbox liner to the pad for extra grip...it works very well for all.but the largest moulds.
Excellent, Stuart. I wonder if a 3D printer or laser cutter would give you more scope for creativity in terms of the design.
He could do a concrete frog and paint it.
That was my first thought too.
I have used 3d printed parts in concrete castings, oil them and they are quite easy to remove
i make concrete plaques and will be sending a cease and desist lol just kidding
very cool, interesting to see your method, with my plaques, the design protrudes out instead of being engraved inwards.
Concrete Plaques NI - if you want want to see them.
Keep up the good work, love the channel 👍
Put a plasticizer in the mix before you pour and it will make the concrete run like water. Okay, maybe not water but it does make it flow. Then, when you vibrate, the concrete will easily get into all the little nooks and crannies and the bubbles will also have a better chance of releasing.
When I used rein fibres rendering my koi pond, I ran over the surface with a blowtorch after it dried to remove any fibres that were sticking out so the fish didn’t damage themselves. Worked a treat.
Alternate lettering that works perfectly for these types of concrete signs are foam letters used by kids to learn the alphabet. They are available in a variety of sizes and fonts ….. (but not as varied as your use of computer printed font followed by cutting each letter out.). The foam letters are compliant enough that very little damage is done to the concrete during de-molding. I E6000 glue to attach each reversed letter to the bottom of the mold. After de-molding, my mold was in good enough shape that I could have used it again. My end product was a beautiful grave marker for my beloved dog, Patches.
A few years ago I cast a large number of faux stones (about 800 in all) in plastic molds. To help remove bubbles and settle the concrete mix, I took an old metal shelf unit, and attached my hand held saber saw to the underside of it. (with the blade removed) Turning on the saw provided ample vibration, settling the concrete is a matter of seconds.The shelf unit was large enough that I could fill a mold, and have 2-3 previously filled molds continuing to settle at the same time. I hope this idea is helpful to someone.
i put a bolt on the frame beneath and use my impact driver to create vibrations in the whole structure - works great
*Thats super cool. This can be used to pack all type of holiday decor, desk signage, or any outdoor signs. Thank you for sharing.*
As a relatively new subscriber, I just want to say , A Big Thank You.
Although I'm quite confident at most D.I.Y. on occasion there has been the odd forgot about aspect of a project, your videos have invariably shown a comprehensive how-to-do error free way. Love your channel, so, Thanks again👍.
Proper is as Proper does.
Timely video, I need to cast a replacement lintel to match some others, so this was full of useful information.
Another tip. When making small concrete objects like this use pea ballast. The aggregate being smaller is better for smaller castings. When we used to cast cills in situ we had one shot and they used to come out perfect. Using 20mm ballast the aggregate is just too big.
16:03 I love the custom music with voice over bit 😆 At first I thought you found the perfect track and then after the 3-4th comment I realized, "oh he's actually done this all himself! Now that's Proper DIY!"
We've made boundary markers for years on the farm here in upstate New York doing something similar.
We just made a new one with the twist that we 3D print the lettering now and put mold-release on the letters (vaseline jelly).
Cheers!
If you wrap them the letters with clingfilm, it will allow the letter forms to be easily removed from the clingfilm before peeling the clingfilm from the concrete. Also, for simplicity, use children's wooden letter and number sets, unless you want serif letters. If you're going to reuse the letters, drill and tap (wood) or glue in (plastic) threads into the letters for removal, fill them with grub screws topped with putty during forming. One thing I've done before, for a better finish, is to build a bottomless inner form out of 1mm sheet metal that is 2cm shorter and 2cm narrower on each edge than your large form. Use cement to fill the first 2cm of the main form, then hang the inner metal form inside the main form, keeping the spacing even on all sides. Fill the 2cm space between the inner form and the main form with cement before filling the remaining space with concrete. When the form is filled, remove the metal form and use your vibrating tool to bind the concrete to the cement and to remove the bubbles before setting. This will prevent the concrete aggregates from marring the surface or filling the voids in the letters. Also, concrete takes 11 days per cm of thickness to fully cure.
You can also do lines and flourishes, and if you want the words to require little to no maintenance, fill them with silicone.
Excellent video, its very nearly as easy as you made it look (unless you're me and can't cut a line straight)!!!
"children's wooden letter and number sets,"
Hi I think instead of useing a sander u can get rubber foot attachements for a SDS drill that heating engineers use to un clog rads
I just finished watching one of your other videos about SDS drills and just had the thought that could be a perfect tool to release bubbles.
The air voids actually increase the ability of the concrete to withstand the temperature variations in exterior use. We intentionally add “air” (essentially a soda that creates bubbles ) in exterior mixes to increase strength and decrease the air in interior slab pours to decrease bubbles in the finish process of a hard troweled floor.
You can always sack the finish with cement while green to fill the exterior small pin holes from the air.
Done it! Made a couple of grave stones for dogs. Laying flat you can move right over it.
Ann summers sells one of those pokers too
Nice work, looks good. I've made concrete signs before but went at it a bit differently. I router a piece of wood with the words making a negative mold, spray with release agent, install some sides then pour in some plaster paris. Take that and use it as the bottom in my concrete mold with more release agent then pour concrete. Also I just use a palm sander as a vibrator on the outside of the box......kind of the same I guess.
Well done and good work they need a cement sealer for them to stay for a long time
Very interesting as usual. If you make any more I'd suggest compacting the concert as I did and I'm sure you did in days gone by when making concert test cubes. Fill a third at a time and use a 25mm square tamper as your moulds are a similar height to the test cubes. That method was always very successful in removing air bubbles from the sides and interior as could be seen when they were crushed. Always look forward to your weekly video with expectation. Regards Alan 6:47
Great stuff!
Try a damp mix similar to the way concrete blocks are made. I used to make ornamental precast stone for buildings in NYC. We would make a shell of damp mix and fill it with wet mix. The surface look more authentic this way.
I find using childrens plastic magnetic fridge letters work well. Ideal for small garden signs.
I understand its not the same and as satisfying as making your own letters.
I make concrete molds for a living you did everything spot on except pull the piece the next day all imperfections can be filled with a thin slurry and rubbed to a uniform finish mild acid wash also great presentation though 👍
Back when i did building construction in school (1985-ish) we used to make up a paint on slurry of concrete powder, fine sand and water.
First we'd oil the mould then paint all the surfaces of the mould with the slurry, then half fill, add reinforcement, then fill up to the top.
Back then our only option was as you rightly pointed out, hit it lots with a hammer 🤪🤪 and then strike off.
Lastly tap in any required strips of beading for a drip channel ( window sills etc)
Made them pretty much perfectly smooth
👍🇮🇪👍🇮🇪👍🇮🇪👍🇮🇪👍
The air gaps look good to me but it's a personal thing. Regarding the reinforcement fibres, if you blast them with a heat gun they shrivel to nothing and the concrete no longer looks 'hairy'. It's a weirdly satisfying job. The ones I have used in the past have been some sort of plastic and not actually glass fibres, hence the heat gun shrivelling them up. On the vibration point, I woder if anybosy has tried a multitool as they are quite violent at the business end. I haven't tried but was intending to on my next pour, whenever that may be. Anyway, super fun projects and thanks for the vt.
Polypropylene
Great video! Love your saying about you live and you learn. I learned that using a concrete sprayer to do the first face coat gets you near perfectly smooth surfaces.
I use 2 inch or 5cm pink foam board insulation to make my molds. I use a 4' x 4' or 120cm x 120cm CNC router to in the lettering and or shapes into the foam. I've always brushed on a mold release and let it dry before pouring the concrete into the mold. I need to try your mineral oil as it would be less expansive. I use the bag concrete and use a sifter to remove the larger pebbles that are in the concrete. I would mix my own concrete, but I haven't run into an issue yet to persuade me to change. I did have a mixer but really didn't need it, so I got rid of it because I never see me make large runs of anything concrete. I learned hand batching in a plastic concrete tub is much better and cleanup is faster. I have a vibrating table and some of my projects still end up with bubbles. I liked your video as it shows the craftsman ship you have.
Love the concept ... great result. You could fill the letter voids with bright day glo epoxy resin ... really make them pop rather than just using the cut in. 3D print the letters in PLA and then just hit them with a heat gun at 90C and they will soften up enough to come out easily with no damage to the surrounding concrete ... Also a slight draft on the molds and you may get the concrete to release without pulling apart the mold.
I wonder if you get phosphorus epoxy, so the letters would glow at night
Void in the house number would enable slim line LED backlight - I’m sure would look good and flex those skills even more!! Love your vids, thanks
To reduce the voids from bubbles I would try adding plasticizer to your concrete mix. It makes the mix behave like you added more water without adding more water. The bubbles will float to the top much easier.
I've used the fibres in rending mix, I got better distribution adding them to water first in the mixer until they had evenly spread out then add the dry ingredients, adding them later they seem to clump together.
Add some SBR to your mix and you greatly increase MPA along with moisture resistance, perhaps not for this use but other projects
If you use granolithic concrete ballast rather than the standard stuff you get from the builders merchant, you'll find the detail comes out a lot cleaner. It goes from dust to 5mm rather than to 20mm. Also you can fill any small voids left by the bubbles with slurry of straight cement.
I’m a lettering artist and I would still probably just get my letters lasercut from either foam or mdf for this. Ideally something that doesn’t absorb moisture. Smaller aggregate too and a bit lighter reinforcing metal. You’re not making a lintel afterall. But good stuff. Your videos are great.
I saw TH-cam video of some guy making concrete thombstone for people who can't afford granite tombstones for their dead family members.
that was around 10 years ago.
used mostly similar technique, but he made the letter using hard sponge material, which can hold shape, but still flexible enough to be removed easily.
Try Cementall, it is the most expensive but cures really hard and smooth as glass as it does not require an aggregate. Also, try raised letters instead of recessed. To achieve raised letters/designs on your final product you need to recess them into your mold and also make sure they are backwards so they reflect on the final product properly. I use foam board and a Shaper Origin to route out the design in the foam, a router or traditional cnc would work as well. You can build a standard mold around the foam or router/cut the mold into the foam. These are really fun projects.
Coating the mould with cooking oil will prevent concrete sticking to it, tip from Tommy Walsh many years ago and it works 👍
One thing you could try is buying silicone mould with letters (or even making your own, but that is another project on its own), then casting them from paraffin wax mixed with sand. They will be almost rock hard, yet easy to remove from concrete with heat gun. You will be able to reuse sand and wax too, if you heat it above container to drip out (wax may need some replenishing).
Great vid thanks. I have an elephant mould that has lots of curves. I was advised, when i bought it, to make it sloppy. I've had them outside for 20 years and they still look good.
This was really a lovely video to watch,will try this,Thankyou so much Stuart, Timothy from South Africa
Mortar mix, sand 3 to 1 cement will have less bubbles. The finer the sand the better, plastering sand is rougher, can also use dye mixed in.
I know what im making now for the garden A 'GNOME OFFICE' sign.......BRILLIANT!
Find a paint mixer such as used in paint stores, with a solid top. Cover the top with cork, add straps to hold the forms, and put the top the same height as your work surface. Put in a large can of paint, or water filled can, and shake away. You may, possibly, have to build higher sides to the forms, or cover them tightly when shaking.
I used 6mm laser cut MDF with no bevel as had them laying around the worked quite well, and you can soak them to get them out in a more gentle exit procedure.
I also used varnish and WD40 as a releasing agent because that's what I had.
For the molds I kept some of the better bits of old kitchen i had replaced which are perfect. There's always tons of that down the recycling centre, have a word with the staff.
If you want screw you sign to a wall as i did a couple of dowels to go through will suffice for the screw holes or in bed something in the concrete like a hanger or hooks, or some bolts if you are think of a wooden plinth or similar
I like to use my oscillating tool to get rid of bubbles in cement. If you are pouring into a form, leave an extra lip large enough to set the oscillator on and clamp it to.
for the vibration portion and removing bubbles, perhaps consider using the table saw table. Fix the boxes to the table, turn on the saw, and let the vibration from that do the trick.
Excellent video illustrating why I would never do this kind of thing.....
loved the vocal effect, fitted nicely with the music, great channel
Yes..As Alastair below comments, I too thought your mix was too stiff for bubbles to rise through. I would use a very wet mix for the first pour then before it goes off a stiffer mix can be added for the bulk of it. Also, if using an aggregate you need a small grain in that first pour wet mix. This should give you a fine smooth surface finish with a more rugged matrix underneath. Of course it is all experiment to get the best result.
An outstanding instructional. Well done with lots of detail. Thanks!
Interesting project! I would use a cement plasticiser on a job like this, to improve the slump without adding more water... I find it significantly reduces voids.
Maybe try some cement dyes as well?
Great that you kept your moulds reusable, to play with again!
Stuart love your video… a scroll saw is a fantastic tool for the lettering. I got mine for £120. Brilliant bit of kit!!
For the size of these works you don't need any reinforcement. Fibre is detrimental to the finish of exposed concrete. If you're concerned about freeze-thaw cycles, 10 gauge wire is more than sufficient. The concrete mix is of more concern. Small pieces with fine details need smaller aggregates. Exposed to weather they also need a higher cement content and 6% air entrainment. The pencil vibrator may have contributed to the bugholes as it has a tendency to actually create bubbles on the surface resulting in an Aero bar concrete.
I made cast concrete gutter slabs for my mum's garden patio 12 years ago. Each used a 30kg bag of premixed 27.5MPa (4,000 lb) concrete mix with a squirt of Fiery liquid to create the micro air bubbles. The form was made from 26 gauge galvanized sheet metal. There was no reinforcement. Each gutter was about 45cm long and 5cm thick thinning to 3cm. I used a hammer ( I tried an orbital sander for the vibration, but it was ineffective). The piece's were removed from the forms after 24 hours. One (of 13) broke because I was clumsy. The remainder are still in place without damage beyond scrapes and chips from the spade done to remove ice and snow. That 12 Canadian winters!
I think they came out great. What if you used a cheap HDPE cutting board for the letters? Be a bit more money, but they'd probably slide right out and you wouldn't have to sand or varnish them. You could pin nail them to the particle board to hold them in place.
This is the first guy that is watchable without being patronising condescending or American. I have my own property maintance company and don't want to be lectured to, like I'm an idiot. This guy is spot on with the level of information, his cheery approach and his obvious competence and great ideas. Trust me you never ever know it all, however long you've been a tradie and finding a TH-camr that is watchable and gives you good tips is RARE!
"...without being patronising condescending or American..." 😶
An interesting experiment Stuart, they came out pretty well I think, thanks for taking the time to make and share this with us all, your editing and use of different music etc was really good on this one - more great content - Cheers !
Keep the water content in spec and add a wetting agent and the slump will increase greatly (without loss of strength) allowing the escape of trapped air with vibrating. Quicken cure by wrapping in black plastic (to keep moisture content up) and put some heat into it, like in the sun>
Nice! Letters are a hassle to make though. Wonder how insulation foam would hold up....