Jeweling metals, need info

[mklotz]

The rubber rods filled with abrasive you mention probably refers to Cratex products, examples of which are shown here...

https://www.amazon.com/s/ref=nb_sb_s...=1PG71K5J1ET9R

As an alternative to Cratex, I've had some success using sections of wooden dowel with a patch of leather glued on the end. Smeared with lapping paste and rotated in the drill press, they leave a nice circular swirl.

An attractive jeweling job requires two things. First the spacing of the circles must be consistent; spacing errors will stand out and look bad. Arrange some method of mechanically stepping the work between swirls. Don't try to space by eye. Second, the pressure with which the tool is applied to the work should be consistent. While this is slightly less of a concern than the spacing, it's still important.

Be sure to experiment on some scrap before working on the amplifier. Undoing a bad jeweling job is very difficult.