I took a rare 1930s copper fog horn to a media blasting company for removal of the light copper oxide some old paint patches prior to polishing. I asked for very light soda and/or fine bead blasting, but they screwed up and blasted it all over with black silicon carbide, completely pitting the crap out of my rare collectible! It feels like220 grit sandpaper now. I ultimately want to buff the horn to a mirror finish as I have done with similar models in the past, but I'm now a lot farther from this goal than before the blasting incident, and I'm not sure where to start repairs. Because I'm seeking damages from the blasting company, I also need to come up with a plan so that I can give an estimate for the cost of repair. There are only 3 of these horns known to exist, so replacement is not an option, nor is there any known value for the item. Restoration is really the only option apart from fabrication of a replica from scratch.
I'm wondering what my best option is for resurfacing the horn to a state where it can once again be ready for buffing. Would bead blasting hammer the copper to a smooth finish again, or is my best bet to use scotch brite wheels to sand out the roughness? It's too deeply pitted to get anywhere with hand sanding or hand pads. The rolled copper sheet is fairly thick, perhaps 3/32" or so, but I'd still like to remove as little material as I can get away with so that integrity is preserved.
Any related advice is also welcome!
Adam adam AT airraidsirens D0T com