Huertecilla wrote:In metal objects that presents a challenge.
´Removing´ scratches per example is only possible by fílling it. Not by removing the surrounding surface as that will alter shape/dimensions.
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Like Bruce, I have a tool & die background - I was a form grinder. Same situation - much tighter tolerances were being held, routinely. I believe on some watches you can [theoretically] remove some metal AND not dramatically alter the shape or dimernsions - tolerances are tolerances, any pieces originally machined to the high limit could certainly be taken down toward the low limit. Problem is most people don't have the tools, setup or skills to do the work. I
have everything necessary - surface grinder, radius dresser with extension to dress up to 15" radii, Harig Grind-All
http://www.harigmfg.com/grindall1g.html, surface plate, gauge blocks. gauge pins, and two large cabinets full of v-block, vises, planers gauges,etc(mine and late father's, also toolmaker). But it is hard to justify spending several hours setting up one piece so you can get the correct radii, correct angles,etc. And you need to make a holder to hold the piece very securely to even start on THAT, and to perform the work. No point in running a decent case under a grinding wheel and flinging it into the wall(exposing yourself and the equipment to danger also.)
Bruce does nice work on his rebrushing, a lot of us do nice brushing(particularly depending on mood, steadiness of hands, etc.

). But none of us can recreate the original factory finish on most of the pieces because we are not
grinding the surface in one smooth pass, as was obviously done at the factory.
Back to the tolerances. With glass/crystals we see a lot of variance on the thickness, seems to be .010-.015(.25-.38mm) on Pulsar glass. And the faceting seems to vary quite a bit too. A piece of PUlsar glass with minor scratches and some edge roughness can often be taken down a little on the face(making facet smaller too), then facet increased a small amount to bring back to size. Roughness gone, scratch gone, still totally within tolerances.
