Aircrete is collapsing
I have had difficulty creating long-lasting foam using the seventh generation dish soap. The aircrete mixes well and pours with a light velvety texture, however after about 20 minutes in the mold, it starts to rapidly collapse, within a minute or two, down to half of its poured volume.
I am using the ratios found on the website:
Little Dragon 5-gallon Bucket
Aircrete 5-gallon Bucket (added in this order)
-10.5 lb portland "low alkalai type II/V" cement
-6.3 lb water
Concrete Slurry is mixed thoroughly
-rich hearty foam @~60 psi is added to fill up the rest of the 5-gallon bucket
Aircrete Slurry is mixed thoroughly
This mixture is about 1/3 concrete slurry and 2/3 foam, per one of domegaia's videos.
This same mix and procedure had worked out for one batch in the past and it hasn't worked since. Maybe because that was on a somewhat hot day (85 degF), it is colder now (60 degF), do you think that temperature difference would create such a drastic change in aircrete formation? I cant think of anything else that would be different..
Any advice is appreciated. Thank you!
^^some examples of aircrete collapsing. that aircrete shown in the cardboard box was filled to the brim. and it collapsed more than half the height! any tips come to mind?
I doubt it has anything to do with the temp. When it collapse like you discribe it is almost always caused by the wrong foam density. Do you have a good scale? The foam should weight between 80 - 100 gram/lt
or 3 oz/qt.
Make sure the foam density is correct and please let us know how it worksout.
Make sure the foam density is 80 - 100 gr/lt (3oz/qt) then let us know how it works.
leroy last edited by leroy
Thank you for the feedback, I just confirmed the weight of a liter of foam on my kitchen scale to be 92 grams per liter which is in the range you mentioned. Again we are using the seventh generation soap as a foaming agent while running the little dragon at 55 psi. The aircrete is still collapsing, same as before.
Please advise. Perhaps a new foaming agent is in order? Or perhaps the well water we are using might contain minerals that react with the soap or perhaps the concrete?
Thank you for your help. Very excited to get our aircrete operation dialed and start building!
ARE your plans for a homebuilt "Little Dragon" still available? They were available a few months back but I don't see plans listed on the home page unless I'm looking in the wrong place; only the full blown Dragon.
Thank you Hajjar,
Dr. Greg Green
San Miguel de Allende Mexico
PS are you having another seminar in San Miguel? 'Missed the last one.
Something is obviously not right with your mixture. Without being there it's hard for me to analyze. I suggest making smaller batches until you get a mixture that works.
AirCrete was new to me up until a few months ago. Have searched around to get better educated about this building methodology. Struggled with investing in the equipment to make some test blocks. Think others have similar struggles. Have recently moved through that struggle and wanted to share a simple way for anyone to make test blocks too. Am new at making AirCrete blocks but did have an idea for those who do not have the equipment and wanted to get started right away making sample AirCrete blocks and gain confidence in this great technique you have shared with us.
Being able to make blocks on a budget to gain a better understanding of how AirCrete mixes up, looks, feels, durability, strength, playing with different fibers, weight of a block wet, weight of a block dry, floats, etc is easy to do once you look at this step by step PDF instruction guide:
Easily making these test blocks has really opened up my understanding of the incredible possibilities we can achieve with this building methodology you have shared with us!
There is so much more we can express with this and be of assistance to helping many people around the planet build affordable shelters to live and work in that are LOW COST, ECOLOGICAL, FIREPROOF, WATERPROOF, PEST PROOF, SAFE, ELEGANT & EASE OF CONSTRUCTION as you define here:
Thanks so much to you and your team, the world is now a much better place!
Thanks, that's a great intro to making AirCrete!
leroy last edited by leroy
Great PDF! Thank you FoamAir for the walkthru. We are equally excited about this material and its potential for long-lasting, economical, and beautiful housing. Seems like we are using the proper ratios based on what you mentioned in the PDF which matches up with what is described through Domegaia's videos and website. I suspect the issue might be with our well water source so we are going to try again using the Seventh Generation dishsoap with Reverse Osmosis filtered water from our food co-op in the little dragon.
Also! In addition to that test, we ordered a bottle of the Drexel Foam Concentrate from RuralKing.com as recommended on Domegaia's Foaming Agents page. We are very exctied to see how this performs as it is highly recommended on Domegaia's Foaming Agents page.
The volumetric ratio between (Water):(Seventh Generation Soap) is 35:1 as posted on Domegaia.com.
For the (Water):(Drexel Foam Concentrate) it seems that the ratio might be 160:1?
What ratio would you recommend for the (Water):(Drexel Foam Concentrate) to make AirCrete?
Thank you for your support, it is greatly appreciated.
We finally have our Little Dragon supplying beautiful aircrete. Turns out the issue was the water quality. We were using well water which for whatever reason was reacting with the foaming agent (seventh generation soap) and causing a reaction which collapsed the bubbles.
I went to our co-op and filled up a 5-gallon jug with their reverse osmosis water station and voila! The collapsing weak aircrete we had known from previous testing became an entirely different material altogether, thick, viscous, holding its shape. Beautiful. Just like the videos.
I would like to mention that I had a hard time finding any information regarding water quality and its effect on aircrete. I think that this should be mentioned on the front page of the little dragon, it took us a few months of testing to overcome this obstacle and it would be nice to save others the trouble!
Thanks Levi, I didn't realize that water quality is so important. I guess we've been lucky with our city water supply. I wonder what it is about the water that makes a difference? I haven't found it mentioned as an issue in my research. If any one has information about the importance of water quality, please let us know. Thanks!
@FoamAir Thank you so much for posting this!
@hajjargibran Look into "structuring"- meaning- erasing the memory of the water. Dr. Emoto did research on the quality of the water. He found that all water has a memory to it, so what if structuring it would fix any issues with the water? Or just use a reverse osmosis system. Here are a couple links about structured water.
I personally have a small water structurer. I have found it to work fantastically for me.
If you "NEED" me to come to Washington in August, seriously, please let me know. ;o). I'm sad there are no more spots for the workshop.
@hajjargibran While Leroy gives no clue to the water composition, but even type V cement will react to high concentrations of sulfur/sulfates in the water
We have hard well water. If/when we begin using aircrete, we'll let you know if we experience the same.
Water chemistry has a lot to do with concrete! Ignoring your water chemistry when mixing any concrete is an invitation for disaster. Sulfates in your water or aggregates in any portland cement mixture are really bad. Here's a link to more information on concrete and sulfates: https://www.understanding-cement.com/sulfate.html#
@FoamAir I followed this recipe with my own foam that weighs 85g / ltr made with reverse osmosis water and 7th gen foam. My slurry seems thinner and runnier than yours but maybe that is the pictures not showing up well. Also, there is sand sitting in the bottom of the mix. The cement mixes but there is sand at the bottom in the slurry and after the foam is added as well. Did you have a bit of sand sitting at the bottom too?
I have formed it and can hear my foam reacting one in the form, it is gassing off and collapsing. I will go buy a small foamer and try. I have Drexel on the way. This is all with reverse osmosis water, foam and slurry. Thoughts?