04-23-2011, 07:53 AM
Thanks everyone. 
The prototype surface is very small whitish-gray gravel. Awhile back I found a rural parking lot that had been surfaced with crushed concrete (The Houston area doesn't have alot of matural gravel or rock, we are mostly sand and clay. When they are redoing roads around here, they run the busted up concrete through a crusher and then use it as if it where gravel). There was alot of fine powder left in piles, and it was quite white colored, so I picked up some of that and took it home and sifted it. When glued down using the ballast method, it ends up being more gray than the prototype surface, but I'll live with that. Although, I am experimenting right now with a 50/50 mixture of concrete dust and plaster to make it whiter. I have a batch of that applied like ballast, I'm waiting for it to dry before moving on. Another thought is to use some white ceramic tile grout, I have heard of that but never tried it. Any thoughts?
One thing about the concrete dust is that it has a high surface tension. Even 91% alcohol wants to bead up on the surface, but it does soak in after 30 seconds or so. Once wetted, the diluted glue soaks in well.
The prototype surface is very small whitish-gray gravel. Awhile back I found a rural parking lot that had been surfaced with crushed concrete (The Houston area doesn't have alot of matural gravel or rock, we are mostly sand and clay. When they are redoing roads around here, they run the busted up concrete through a crusher and then use it as if it where gravel). There was alot of fine powder left in piles, and it was quite white colored, so I picked up some of that and took it home and sifted it. When glued down using the ballast method, it ends up being more gray than the prototype surface, but I'll live with that. Although, I am experimenting right now with a 50/50 mixture of concrete dust and plaster to make it whiter. I have a batch of that applied like ballast, I'm waiting for it to dry before moving on. Another thought is to use some white ceramic tile grout, I have heard of that but never tried it. Any thoughts?
One thing about the concrete dust is that it has a high surface tension. Even 91% alcohol wants to bead up on the surface, but it does soak in after 30 seconds or so. Once wetted, the diluted glue soaks in well.