Buffing Raw Copper
Q. I have a question about how to get a high shine on raw copper. I was given some raw copper pieces to incorporate into an art installation, but they have a matte finish. I was wondering how to go about buffing or polishing them to a shine. Even if anyone has any links that apply I would appreciate it. I can only find information about removing tarnish from copper on the NET. I need to add a shine to the clean pieces I have.
Thanks in advance!Darren White
artist - Pittsburgh, Pennsylvania, USA
A. Buffing is buffing..all done near the same with whatever material your working..you take your work piece, find a grit polish or sandpaper a little bit finer than the finish on it already and work the material down to that grit...then you go a step finer and repeat...then a step finer..etc etc. the rougher the initial finish is the more coarse grit you have to start off with. for most of what I do 220grit-400grit-600grit to medium buff- fine buff (green jewelers compound) works well. But this may be too aggressive or not aggressive enough depending on your piece. There are of course tumblers, electropolishing etc that replace this process but this is how you do it by hand.
Make sure you remove all the previous grits scratches before moving onto the next grit..if possible with each grit work perpendicular to the previous grit (more uniform finish and lets you readily see if you are removing all the scratches) there are other little tricks to it but not knowing what shape/finish your working not sure if they apply to you. I'm sure if you do a search on this site you'll find several posts on buffing.Jason Aube
- Flint, Michigan
A. I would go from a 320 to 400 to 600 to 800 to 1,000 to 1,500 to 2,000 grit sandpaper [linked by editor to product info at Rockler] sanding back and forth then on the next grit sanding up and down then after 2,000 grit go to a 0000 steel wool [linked by editor to product info at Rockler]. Then if you can get it, fine Bronze Wool [linked by editor to product info at Amazon].
Then buff it with a tripoli [link to product info at Amazon by ed.] compound,
then a white rouge [linked by editor to product info at Amazon],
and finally a red or jeweler's rouge [linked by editor to product info at Amazon]
This may seem like the long way but you'll get almost flawless results.Simon Dupay
- Roseville, Minnesota
How to buff highlights without scratchesMarch 26, 2015 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. After patinating a piece of hammered copper, I would like to buff it to highlight the hammer marks. The finest grade steel wool still leaves noticeable scratches. How can I gently buff it?bob douglas
hobbyist - oakley, California, USA
March 2015 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
A. Hi Bob. Buffing challenges the patience of the most patient because you can't get mirror smoothness without using extremely fine-grained and gentle abrasives -- but such gentle abrasives have so little cutting power that they can't remove even tiny scratches in a reasonable length of time. So you're usually stuck with using several in sequence as described by Simon.
Ted Mooney, P.E. RET
Pine Beach, New Jersey