Hi bro know that ppl in RC uses that but have you wonder what why they had added the marine paint later ?? Or they have switch to epoxy resin to create the rockscape ..
It because the form could not withstand the UV ray from the MH and it started to melt ?
Why i know because i am one of them using the form to stick LR together. But after 1yr the top part which is nearer to the surface of the water, the form and the rock started to fall apart. the form become a mashmellow soft soft and i have no choice but to tear down my rockscape.
Given a chance will not use that again but will go for the epoxy resin With marine paint.