It was interesting to see Meevis’ tutorial…I hadn’t thought of pushing the prongs over and THEN cutting them to height. Other authors cut the prongs to correct length first, then notch them and push over the tips rather than just leaning the long length of the prong over the stone and cutting off the length that’s left. Just another illustration of how there isn’t one right way to do things. In Meevis’ method, the cup burr rounds the top of the prong and there isn’t a need to take the cup burr down to where it might contact the stone. Note that in his example the prongs are round in cross section. If the prongs are square or rectangular, there can be a problem with transitioning one shape to another and maybe this is why you’re feeling like the burr needs to come down to the stone?
Interestingly, when I consulted two old books on setting, Wooding’s on diamond setting and Wykoff’s, which treats both diamonds and colored stones, their approach was different. Maybe because it’s less likely to mar a diamond with a burr, Wooding rounds prongs with a burr after they are pushed down. Wykoff, maybe because of his experience with colored stones (he was a faceter as well as a jeweler), says you should prepare the prong completely, including notching it, thinning the back if needed, and shaping it with a burr BEFORE pushing it down over the stone.
If you’re going to use a burr after pushing down the prong, you should make sure the edge of it is smoothed and polished, which will make any scratching or marring less likely. Then rotate the cup burr as needed as you spin it, but don’t come down to the level of the stone. Clean up any flakes or metal burrs with a barette file or graver and polish with a wheel (eek! careful!) or pieces of very fine sand papers or even a scotch stone and burnisher…any method you can think of that doesn’t use an abrasive surface against the stone.
Me, I’m going to prepare my prong as much as possible before pushing it over. Realistically, there may be some smoothing of the edge of the prong to be done so that it doesn’t snag on clothes. I have a very fine cut barette file to use for this and then the surface filed is actually on the bottom surface of the prong, where you don’t really see it. you can use some kind of very fine sandpaper (crocus cloth) or hand buff there if needed. Or use a knife graver…diff’rent strokes for diff’rent folks, I guess. -royjohn