For the past six months I've been asking around for a "For Sure" hard coat with EPS foam. I currently have a couple of signs, in the shop, and need to get working on them.
To save time, let me go over what I've previously done. Styrospray was my first attempt and I may return to it. It's main problem was it's too flexable. I need a coating that's truly hard. Hard enough a baseball will bounce off of it with any damage shown. I've built several which are now showing some faults.They were sprayed with exterior succo/cement. They are now showing joint cracks. Concrete and stucco end up being heavy when applied to a crack proof thicknes. Although they're definately hard enough, details are quickly hidden, and they are way too heavy.
It looks as if I'm going to need two different topcoats. The first as a hardner folowed up by a more flexable texturing coat.
The latest test was with good old Durhams Rock Hard Putty. That stuff is a dream to work with and may be the winner for my first coat.
These signs aren't cheap and should get the best of materials. Suggestions would be appreciated.
Where is Bill P. when I need him?