Review on ArtMolds High-Grade Copper Powder: Effortless Cold Casting with Polyurethane Resin for Stunning Sculptures, Home & Office Decor - 1lb/350 Mesh by Tara Ford

One-time use: Dust a silicone mold with this copper powder and carefully pour in the fast-curing polyurethane (shelf life is a few minutes). After the polyurethane has hardened, wipe the surfaces and especially the cracks with solutions for aging patina and copper. After complete hardening: Lightly sand the surfaces with very fine steel wool or very fine sandpaper. The result is an aged copper appearance that can be very authentic and impressive in some cases and a bit disappointing in others. You can fix the result with wax or varnish to stop or slow down further changes. There are several videos of the whole process. As explained to me: The copper particles in the bag are dull brown, not shiny copper. After slight abrasion they look metallic.