“A friend suggested a product I was unfamiliar with, so I decided to research and do some testing. The chemical name is calcium hydroxide… ca(oh)2 (calcium carbide), a by-product created in the production of acetylene. I went into Managua to a place that manufactures acetylene for welding. I found a big pool of jade coloured water, which is how a pool of lime looks. Calcium carbide lime when mined and then fired becomes calcium oxide co2 or hydrated lime. These two substances have the same structure and are from the same family. The company asked me if I wanted the gel or liquid. I bought the liquid as my original intention was to use it for painting the polypropylene tubes. The super adobe tubes deteriorate in the sun, so you must cover with plastic while you are building, or paint them to protect. Painting is so much easier but more expensive. Carbide is stupid inexpensive — $10 for a huge drum. As it turns out, I discovered you can use it as plaster. It turned to a nice thick paste after several weeks. I did several mixes and test patches on the walls until I found the right mix of coarse sand and carbide. It was rock solid after 2 months. This is a natural product and still allows the walls to breath while having the ability to repel rain. It is affordable to use in construction and I want to pass this on to the local Nicaraguans to aid in affordable housing.
The fotos are of the carbide used between the bags initially to build out and level the voids between the rows of bags. (Note Rosita claims that it is necessary to wear Austrian crystal drop earrings when applying the mix. stylin´). You want to leave it rough so the next layer can key into it better. Next we cover with chicken wire and then a coat of lime mixed with coarse sand. The final plaster will be lime and a very fine sand from lake Nicaragua. I am testing some lime mixed with blue ochre but cannot get the colour I want. My earthbag buddy in San Juan del Sur has an interesting array of test panels using different mixes of lime wash. I hope to do the same and find the right colour to paint with next season. Much interest from all walks of life with the build. I have been approached by several people interested in me building for them and acting as a consultant. Quien sabes?”