Testing home-made cellular concrete to see how well it carves. Foam-making machine based on these designs: • How to Build a Simple ... • Air Crete Machine for ...
How To Keep Bubbles Small Keep track of your total desired volume, and add foam to the wet mix to reach that level. You can pump the foam under pressure. Inject the foam into the bottom of the wet mix with a stirring motion until the desired total volume is reached, then stir to homogenize. *Fresh air becomes captured if you stir too fast.* Use a vibration tool. Plunge it into the aircrete so that the largest bubbles rise to the surface. _Viscosity will keep the smallest bubbles in suspension, which are the only ones you want anyway._ Add more foam to restore desired total volume, stir and vibrate again. Pouring is another stage when air can be entrained. Avoid large drops where the aircrete can accelerate into the mold, pulling fresh air inside. Pour onto a shovel or hoe held at the surface.
I just use a paddle mixer with stainless steel scrubby pads wrapped up on the end with a piece of window screen to whip up my foam. To make the foam a certain density, say around 3 oz per quart, I just put 1/2 gallon of water in a 5 gallon bucket and add soap until it will whip up to a full 5 gallons. That gives me 4 lbs of water (1 gallon of water is 8 lbs) or 64 oz and with my soap ( I just use cheap car wash soap since it's made to foam a lot) it's just 3 Tablespoons so around 3 oz and 5 gallons is 20 quarts, so 67 ounces / 20 quarts is 3.35 oz per qt. I use this method to ensure that no matter what soap I'm using I can always bring it to the proper density and I don't have to play around with air pressure settings. It's also faster, cheaper, easier and I can use the same paddle mixer to stir the cement slurry and do the final mixing without removing the scrub pads. You can increase the quality of the bubbles by adding simple syrup (table sugar dissolved in an equal amount of water by volume) or glycerin to stabilize them. I'm also planning to evaluate the use of elmer's glue and titebond III exterior glue. For reinforcement you can use dog hair from a local groomer or people hair from a barber shop. The fuzz that protrudes from the surface can be burned off. You can also use straw but it's better to use that with a lime based cement since the lime will petrify the cellulose. It's fine to throw it in a portland mix and see if you like the results though. I've considered other ways to produce foam that may have beneficial effects in the final aircrete such as peroxide and simple sugar (elephant toothpaste style with sugar as the organic compound source, the reaction fills all the tiny bubbles with oxygen), vinegar and baking soda foam (the bubbles will be filled with carbon dioxide), I'm not sure if glygerin and pot perm will create foam but they will catch fire when exposed to one another so I plan on testing to see if it will produce a fast curing foamcrete by increasing the internal temperature. For this same effect I'm considering using quicklime with clay as the binder rather than portland cement.
This is absolutely brilliant! Do you have any videos showing off the process? How does the dog hair effect the quality of aircrete when you're carving it, scraping it, etc? What are you using your aircrete for? What's "pot perm"?
Thanks. I don't have any videos of any processes. I may shoot some when I get some down time, but I'm not a RU-vid content creator myself. The hair in the mix does make it more difficult to carve smoothly unless it's cured and dried, but then it's better to use electric carving tools on it. Once the cement is set firmly the hair is shored up enough to snap through more cleanly with a carving tool. Any fuzziness can be burned off but I'd just use a basic aircrete block for carving, carve it while it's still softset, let it cure, polish it, seal it, create a glove mold of the carving, then use the glove mold to cast finished copies with reinforced aircrete. I'm using aircrete for making walk-in coolers, rocket stoves, kilns, garden bed rafts/bed toppers, exterior window shutters, siding, decking slabs (cast over wood grain textured forms), yard ornaments and anything else I can think to do with it. For some of those mixes I'm using shredded styrofoam waste as an aggregate. I'm using sieved charcoal bits from my charcoal kiln waste and using the ashes as a hydraulic cement component as well, and I'm also working on different proportions of native clay soil mixed with the cement and without cement just to test different refractory and durability properties. My next project is mixing just clay with foam, drying it, cutting it into half inch cubes and firing it in the kiln to see if it will make a good lightweight stone for flood and drain garden beds. Pot perm is potassium permanganate. It has various uses but it's sold most cheaply in bulk as a water purifying agent. I've also seen how people make hypertufa as a lightweight concrete mix in which they just mix equal volumes of portland, peat moss and perlite and add water until it has a cottage cheese consistency. It's a formula mostly used for flower pots. I'm going to try it with aircrete by mixing an additional equal volume of foam into the mix and subbing shredded styrofoam in for the perlite, and shredded pine needles in for the peat moss. I have too many ideas to get to all of them quickly, so if you want to try some and make videos on them I'd enjoy watching them.
@@christophersmith8014 Wow thats great info Christopher - I have made hypertufa with sand, portland cement, perlite, vermiculite, hay and peat and its quite strong for small items such as pots for plants, just made the mixture up as I went along - well before the internet existed! I am looking at making aircrete to do totem poles but just wondered if you had seen anyone else do it and how I could reinforce something 12 feet tall and only a foot or so wide - would just a rebar around the outside do it - any ideas?
Christopher Smith I wish I had thought of the paddle mixer before I bought my foaming gun. I know that creating content has got to be time consuming, but I think we'd all love to see what you come up with. If you do come up with a magical recipe can you email me - annasorakim@yahoo.com
Heh, you brought out the sawsall, and I thought 'oh here we go, someone's gonna lose an eye! ' but no. It was surprizing to see how well it worked. Glad you didn't lose an eye, you just keep on with that. Thanks! :-)
Increase psi decreases foam weight. Decrease psi increases foam weight . I guess the more psi the more air in the foam. Foam should weight somewhere around 80grams/Liter of foam.
I used a blender to approximate a foam slurry and it does not set up very quickly... in theory it should work without air compressors. But having very limited success.
well done. I think they make a microfine fine cement with very fine sand. wold be easier to polish and create, preserve fine details. and they have polymer cement for strength and water proofing. gives me ideas. still...very well done!
Cool video! I greatly think you If I would be allowed... concrete gets strength from it's aggregates. I would suggest sand, concrete, and concrete bonding agent for final resurfacing. Will produce a stronger but sandy finish. Spray da adhesive + water on sculpture plus add a glue of adhesive to topping mix. I've tried ot without the sand, the Portland fluffs off, little staying strength.
Your not going to be able to change the brittleness, however you can make it less susceptible to cracking and breaking by adding fibers, PVA, Glass, basalt, or even paper [AKA papercrete]. Since your looking to carve I'd suggest the paper or PVA fibers as they would be much smaller and less obtrusive to your carving.
higher psi makes smaller bubbles making better aircrete. that is why you have bubbles that are not nice. increase your psi to 90 and yur bubles will be better.
Really Good nice video and you are certainly talented thank you for sharing your gifts to the World. I want to make one of these Foaming Machines for a Large Quantity of Air Crete. God Bless you Brother.
Make sure the foaming agent you use must contain SLSA or SLSE , manufacturerey stop using it most shampoos and detergents . SLSA or E is a stable foaming agent but the others not. I wish you have consistent air bubbles in the future.
you can use a solution of copper sulfate to make it turn a kind of bluish color or an iron oxide and water to stain it the brownish orangish colors or a mix of the two it comes out real well on any concrete usually that hasn't been sealed 😎
your air pressure control is the primary consideration for the bubble distribution in your product; the secondary consideration is the steel wool substrate (is it uniform, stepped, or uncontrolled ?) and the third is the brand (formulation) of soap (assuming you are using at least a decent foaming soap).
How about adding "Thinset" or "Flex Bond". I need a substance to strengthen the waffle floor in a Costco shed, so not to collapse the material. Any ideas? Thx
Have you tried to use liquid egg whites, it can be bought at the grocery store. I whipped up some on my first try and the bubbles are very consistent but after it drys it is fragile. The second batch I added water to and it has very consistent bubbles, but I am waiting for it to cure to make a strength test. For a sculpture medium it will be very consistent. I also need to put a plasticiser and a strenthener in it. I am not sure that the egg whites are cheaper than the soap but bubble consistence is great. Make some follow up vids dude.
Brian O'Bryan, I would be happy to share, but there are already 2 videos on RU-vid that show off the foam generator and how to build it. Check out the links in my description. My foam generator is the same as theirs except that I use a larger (4" diameter) ABS pipe for the reservoir tank. After you watch those two videos, let me know if you have any questions.
Yeah I bought the one on another channel, but makes very little foam, this looks like great idea and sort of the direction I want to use it for;) I do need to make some straits and pavers, (hopefully not too brittle) but mainly art! I will stay connected if I come up with good mixes.
I just had only found the dome gaia 600 buck one at the time, so his looked awesome. its nice so I don't feel bummed. Why do you say its a shame? Because i could have made it?
I use to used perlite in my wall design. I wish I knew about this back then. You can add the cement hardener in a gallon sold or try adding Elmer glue to the mix it should make it stronger or cut fiber and add or try perlite .
Rural King stores have Drexel, but they don't ship it. You have to walk into one. stonebrothers.com/shop/drexel-aircrete-fm-160/ will ship out a gallon for $40 delivered.
Yeah but it's a lot more expensive than Suave. It's not entirely as bad as it looks at first glance, though, because it takes less Drexel to make the same weight of foam as Suave, Dawn, etc. I believe that "Drexel-160" is so named because a gallon of it makes 160 gallons of foam. It's used by exterminators, who add insecticide to it. There are other foaming agents used the same, which would probably work as well as Drexel, but their advertising is geared toward exterminators rather than aircrete manufacture. I thinkl the big thing is that Drexel recognized a growing market and slanted their advertising that direction. They actually market it as an aircrete foaming agent.
thanks for the video ,how's the frog holding up a year or so later? I wonder, do you think aircrete would be a good building material for something like a house? or is it too brittle and would be hard to trust ? I'd like to know what you think.
JUST A MIXER WITH SOME SCREEN ON IT TO MAKE THE FOAM, DUMP MORTAR INTO THAT WITH A BIB MIXER, AND A BIG, FAST MOTOR, AND BLOW IT UP A TUBE WITH A LAWN BLOWER.....
