Vera and the Black Scum : Adventures in barrel polishing

Now I must apologise in advance but I fear that this is going to become a rather technical post. You see, while I did spend a good three years at university being taught to be a silversmith I did very little in the way of machine maintenance while I was there. So, when my barrel polisher went arwy on Monday I didn’t have a clue what to do.

Firstly, let me introduce Vera to you all – she’s my barrel polisher. Technically (for anyone who wants to be picky) she’s a stone tumbler, for finishing gem stones, but in principle jewellery barrel polishers and stone tumblers are both just high speed tombola‘s – so it’s okay. Why did I buy a stone tumbler and not a barrel polisher? Because they’re a fraction of the cost of a proper barrel polisher and I’m a poor artisan. (Though in truth Vera was a Christmas gift from the lovely Mr W.)

Anyway, here she is:

She works by rotating a mixture of finished jewellery, steel shot (of many shapes) and polishing soap to give the jewellery a lovely, shiny finish that gets to the magpie in us all. Only, on Monday, this happened:

Hmm. My silver came out speckled with black and grey scum. I had no idea what caused it but it was decidedly ick. So I scrubbed it off with pumice, cleaned Vera out and tried again. Same result. Another clean of the jewellery later and there was no improvement. I did what anyone would do in my situation. I Googled it.

Underneath a lot of confusing internet madness about motorcycle parts and industrial manufacturing I found a handy article which seemed to describe my problem. 6 months of soap build up had left poor Vera all full of alkalines which were tarnishing the silver as they polished it, effectively oxidising it on the move. Even I knew that this was not good. And the solution? Vinegar.

Oh yes, pure and simple household cleaning vinegar has such an acidy pH that it neutralises alkaline build up and lets you start all over again with a happy, clean polisher. Unfortunately a small part of my studio now smells like a chip shop but it did solve my problem. Vera barrelled away for 20 minutes, full of vinegar, then I rinsed her, filled her with soap and ran her again. After that I braved putting in a test piece of jewellery and, ta-da! It came out shiny and beautiful.

Everything else was then barrelled and left sparkling ready for the show in Wirksworth. Vera is now anticipating a happy and restful weekend with me out of the county and hopes that another vinegar bath won’t be coming her way any time soon.

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6 thoughts on “Vera and the Black Scum : Adventures in barrel polishing

  1. Hello!
    I have the single drum version – works fine so far. I always drain the barrel as much as possible after I use it so hopefully I won’t have the same problem quite so soon.
    I use pickling vinegar (the stuff that’s used for pickled onions) as my jewellery pickle. It takes longer, but it’s easier to buy and I know how strong it is (says it on the bottle) so there’s no dangerous mixing process. Just smells like a chip shop, like you say…

  2. Pingback: The demise of the pickle « Becca Williams

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