I have been researching cement options for my new bamboo dome, I wanted something lightweight to cover it, and having something cheap would also help.
I quickly found a lot of information on using a small amount of cement slurry mixed with a very thick soap foam could create a product called aircrete.
Aircrete has been known and used as an expensive specialty product for nearly 100 years, but a recently a couple of innovators have build (and sell plans and parts) to make DIY foam guns for the small builder.
Basically you need an air compressor, a reservoir and a “gun”. The gun is simple a place where the soap mixture is sprayed and air is mixed in at a 90 degree angle to aerate the soap/water mix. Additionally stainless steel scrubber pads or some other material is stuffed into the tube so that the soap is forced into smaller areas to make it more dense.
My DIY foam gun was built without plans, and I made a few modifications to make it cheaper. I have learned a lot on it, and have a couple of attempts at showing the “first use” but each time my poor plumbing skills resulted in blowouts – its quite comical (at least from my wife’s viewpoint) to see high pressure soap foam squirting out of a line and spraying me instead of the cement bucket but I don’t want to waste the foam so I took some time to have a “foam war” with the boy.