Thanks guys, I appreciate the advice and will test silicone next week before moving forward.
Rolf, used Benjamin Moore acrylic latex.
Lex, we have made from single sheet stock and it's Ok to do but painting for us becomes so many isolated paint/dry/paint processes plus the edge detail is difficult to achieve and takes 2 to3 x as long to complete but it's certainly one way to do it. of course thats basically the way sandblasters do it.
Tom & Lex, I'll start the hunt for 5200 caulk and west marine adhesives.
Thanks again for the ideas and help.