Tumbling pmc silver jewellery.

[ljewell]

Afternoon,

Help please !!! I make pmc fingerprint, hand print jewellery and have always hand finished the pieces using polishing papers. My work load has increased so I have just purchased a 3lb tumbler from cookson with mixed steal shot and burnishing powder. I put a batch of items that had been fired and wire brushed into the tumbler, I checked the items every hour and they didn't ever reach that super mirror finish I was expecting. I tumbled them for 8 hours in total and then gave up. The finish was almost pitted and wondered if the pins from the shot caused this. I would really appricate advice on this and recommendations of timings and processes etc.
Many Thanks
Lucy.

[DaisyDaisy]

I don't do fingerprint jewellery but I do work with metal clay (I make discs and washers which I then handstamp). I'm not sure you're going to get the finish you're looking for with no hand polishing at all. I fire mine, wire brush them, part polish them with my Dremel and then tumble them for around 2 hours. I think you need to be careful tumbling impression jewellery for too long because you can start to lose the detail of the print.

Edited to add - the pieces could well be pitted because they've been tumbled too long.

[LydiaNiz]

It is the pins. The pointed ones. Use different shot (balls, satellites, even blunt pins) and it would be ok.

[Melanie]

I had the same problem and got rid of the pins... problem went away

[ljewell]

Thank you for you advice, im now going to spend the evening picking all the pins out my shot!!