Scratches on the drive bands of a cast bullet

[kevin c]

Not the same problem but I had very stubborn galling on a brass sizing carbide ring. It took diamond paste on an oversized bore pellet spun VERY BRIEFLY on an electric drill to remove, and a second application of a finer grit paste to polish the matte surface to a mirror finish without any hogging out (as determined by the diameter of subsequently sized brass).

[WashingMike]

Well I think I had a similar issue but I discovered “How to hone a size die” by Buckshot here. https://castboolits.gunloads.com/sho...t-a-sizing-die

At the end it talked about using 400 grit wet\dry wrapped around a metal rod with plenty of oil and a piece of cloth stapled to a board. You roll it back and forth pressing down and holding either end of the rod. I found that it really polished up the inside of the die if you did it carefully. It got rid of all the sizing marks on my boolits. I did both Star and regular lyman sizing dies that were in need.

WashingMike

[Kennibear]

You can get wet/dry sandpaper in VERY fine grits. I have 5000 grit (not a miss print, five thousand) and it is blue colored. I use it to polish epoxy that my wife casts and the epoxy is clear when done. Steel shines like a mirror. Usually I start no more coarse than 400 for really bad scratches and progress through 800, 2000 and then 5000. I use a wood dowel smaller than the hole and split with a saw to feed the paper in. I use a drill first but finish each grit by hand, going back and forth while rotating the hole. Any oil will work but I have five gallon pails of inactive sulfur and active sulfur cutting fluid so why not! Leaves a mirror shine and those scratches are not deep enough to materially change the sizing diameter.
Besides, larger diameter rarely hurts the group size.

KB


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[dondiego]

You can get wet/dry sandpaper in VERY fine grits. I have 5000 grit (not a miss print, five thousand) and it is blue colored. I use it to polish epoxy that my wife casts and the epoxy is clear when done. Steel shines like a mirror. Usually I start no more coarse than 400 for really bad scratches and progress through 800, 2000 and then 5000. I use a wood dowel smaller than the hole and split with a saw to feed the paper in. I use a drill first but finish each grit by hand, going back and forth while rotating the hole. Any oil will work but I have five gallon pails of inactive sulfur and active sulfur cutting fluid so why not! Leaves a mirror shine and those scratches are not deep enough to materially change the sizing diameter.
Besides, larger diameter rarely hurts the group size.

KB


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Could I use that 5000 grit to polish the lenses of my scratched, old, polarized, sunglasses?

[country gent]

You can but if they are prescription lenses polishing changing the shape will change the prescription slightly. It will also remove or lighten the polarizing. A fine polishing paste on a cotton ball might be better. Also any polishing will lower the "safety" of them.

[dondiego]

You can but if they are prescription lenses polishing changing the shape will change the prescription slightly. It will also remove or lighten the polarizing. A fine polishing paste on a cotton ball might be better. Also any polishing will lower the "safety" of them.

5000 grit shouldn't change the script too much!

[Kennibear]

Yes it will. Unless you are good at it, it will add astigmatism. The 5000 will be clear but not optically clear. I finish with Turtle Wax Polishing Compound. Polishing not Rubbing compound. Your question is facetious me thinks.
But, on a lighter note, a 3" disk w/5000 grit is a good first pass on crazed headlamp covers followed by a foam polishing pad with Polishing Compound to finish the job. Use water or 50/50 water alcohol to keep the plastic wet while using 5000. You don't have to cut all the way down through the deeper scratches, you stop at about 90-95% gone.

KB

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[country gent]

I have polished lenses on old equipment with electric tooth brush ( the older one with the spinning head) and the ultra fine compounds. It works but can cause parallax and distortion.