Mechanical plate stripping

[xiphmont]

Hello from a beginner...

I\'m prepping some antique woodwind castings for a replating job. I\'m actually going to try Copy-Chrome on these (not trying to be \'authentic\'... technological progress is a good thing in my book The base metal of some of the castings appears to be bronze or brass, the others are a white metal... possibly a nickel silver? It\'s quite soft.

Some of the old [apparently] nickel plate remains. As I have a good vibratory tumbler, I decided to try this first rather than a pickle (I\'m uncertain about the plate metal and base metal). I\'m not actually used to using the vibratory tumbler on metal, so humbly beg for some sanity checking.

After a five hour run with medium ceramic triangles, most of the plate is gone, but not nearly as much as I expected (the base metal is fairly soft), and the result is a little patchy. The parts involved are small (started on the posts first, about 3mm x 5mm). The triangles don\'t seen to be getting in to the tiny corners nearly as well as exposed surfaces.

Is this just an example of \'have patience and let it run longer\', or would you recommend an adjustment? In case it helps, the parts I\'m trying first are the posts from an old (1930-ish) Kohlert bassoon. It\'s a common practice today to case-harden posts, not sure if these are as well.

Monty

[xiphmont]

Re: Mechanical plate stripping

An update (of course I\'m playing with it. insomnia is a mixed curse, good for solving problems)....

Changing the flow pattern of the vibratory media seems to have improved things. I have all the posts strung on a loop of wire, and was using a small hopper which mostly kept the loop wrapped up in a ball.

A larger, longer hopper that lets them float long and strung out seems to improve things. The progress of an additional half-hour has nearly completed the job (of course, it was likely mostly along anyway).

Naturally, advice is still wanted and welcome!

Monty