06-21-2011, 10:28 AM
To be "ferrocement" the design would need to fit certain criteria. A dense aggregate is one of those requirements. Cinders are too soft to meet the standards of real ferrocement but would probably make a fine ferrocement-like material that would be suitable for the project that you have in mind. The lava rock that Glovers turns into sand would be a much better choice and would be a lot easier to work with. I've made ferrocement fences using diamond lath for the reinforcing and then troweling onto it a mixture of 2) parts #4 sand, 1) part mortar sand, 1) part cement and 1/10th) part hydrated lime. That will give you a very strong and workable mix.
Let's try that recipe again if my description isn't clear. If you're going to mix a small batch in your wheelbarrow: 50lb. #4 sand, 25lb. mortar sand, 25lb. Hawaiian cement and 2.5lb. lime. Add enough water to make it workable so that it's easy to trowel and will stick to a vertical wall. Remember that the more water you add, the weaker the final product will be.
www.pacificgunite.com
Let's try that recipe again if my description isn't clear. If you're going to mix a small batch in your wheelbarrow: 50lb. #4 sand, 25lb. mortar sand, 25lb. Hawaiian cement and 2.5lb. lime. Add enough water to make it workable so that it's easy to trowel and will stick to a vertical wall. Remember that the more water you add, the weaker the final product will be.
www.pacificgunite.com