So after spraying about 6 inches of papercrete on my dome, the end result was a little more rough than I would like. I patted it down where I could reach and troweled it as smooth as I could but there were still lots of pits and grooves and it was really rough were I could not reach. I found that I could use papercrete like putty if I squeezed the majority of the water out by hand, so I packed all the large holes with this which helped a bit, but it was now looking kind of messy in a non-uniform kind of way.
Then I had the bright idea to mix pure cement powder with water until it made kind of a thick soupy slurry. I put this in a small pail and just threw it on the rough places, or brushed it on with a push broom, or paint brush. It soaks into all the small holes and makes a fairly smooth hard shell over the papercrete.
So far I am fairly pleased with the result. It seems strong, and more water resistant than the papercrete by itself, and it is less expensive than using paint for the same purpose. It does concern me that while I have read quite a bit about papercrete I never heard of anyone else doing this. They always used some kind of mixture but never just pure cement powder and water.
So my question is has anyone else tried this, and how did it turn out?
