Tumbling - types of shot

**TeeDee** · 31-03-2014, 01:04 PM

Also had same problems with my first purchase of shot form UKGE due to excess of pins.
Bought some Cousins UK mix which is an improvement but not perfect for smooth finishes https://www.cousinsuk.com/catalog/co...el-popular-mix
If you don't fancy picking out the pins I guess the ultimate is to mix your own but it ain't cheap. Cousins/Suttons etc should all do different grades you can buy separately.

I still use my old pin rich mix for some textured surfaces such as reticulated or heavily frosted as it seems to work well for me
Tim

**memattaylor** · 31-03-2014, 01:20 PM

Thanks Tim and Carole, i think finding the right shot mix is key, advice much appreciated.

**Binraker** · 31-03-2014, 04:41 PM

I have had very mixed results with tumbling. I use the UKGS mixed shot too and have been contemplating how to get a better finish. Industrial tumbling and vibration polishing can give you and almost mirror finish and I have often wondered what mix of water/surfactants/media/abrasives they use since every shiny metal thing these days is polished in this way and you only have to look at things like Victorinox pen knives to see what can be achieved. I imagine there a different mixtures or different alloys, finishes and states. I would assume that the majority of the "high street" (H. Samuel to Argos) jewellery is finished like this.

Another thing that I have been wondering about is that the tumbling process also peens the surface making it hard again after annealing. So that's a bonus. Also if you anneal and pickle several times to bring the silver to the surface before tumbling that surface must be slightly porous and tumbling will randomly compressing this surface so will you get the best finish or more a "micro hammered" finish? It could well be something one doesn't need to worry about.

That said, I have usually found that any imperfections in the tumbled finish can be removed with a brass brush and/or a quick wipe with a cloth with some brasso (from an old can where most of the stuff has settled out)

**Patstone** · 31-03-2014, 05:09 PM

I have used my tumbler with mixed stainless steel shot and never had a pitting problem, I got mine from Manchester Minerals, all shapes including long bits.

**josef1** · 31-03-2014, 06:33 PM

not sure if this applies to tumblers but I guess it would,When I got new pins for my magnetic polisher the finish was almost frosted ,the longer I ran the pins the better the finish I got (up to a point I still need to be polish on the buffer) I think maybe the pins smooth themselves off with time and that would explain why schools are better as they have been used more only a theory though

**Didi** · 01-04-2014, 08:02 AM

I had horrible pitting the first time I used the mixed shot. Sat for an hour or so in the sun picking out the needles and haven't had a problem since. Nice to know you can buy the individual bits from suttons though. I'd say, pick out the needles, time consuming but worth it.
Didi

**memattaylor** · 02-04-2014, 11:48 AM

Thanks all, I guess the hour or so sorting should be classed as therapeutic and not a waste of time - especially if it works for me!

Thanks again.

Mat

**FloWolF** · 03-04-2014, 09:50 AM

I got my tumbler late last year having already read a lot of such tales, and sure enough I put a flat piece of sterling in for a test and it came out with trillions of tiny micro-scratches giving a slightly 'milky' finish - the pins have been cut from wire with standard pinch cut and each had 2 sharp corners and a razor edge each end.

I considered removing all the pins but felt daunted by the tedium of that, so figured I'd just save for some more of the other (round balls and planets) shot and keep 2 lots, but in the mean time I just set the tumbler running with just the shot, water and soap alone for about 12 hours total over 3 days and now it gives a vastly improved finish not too far off 'mirror'.

Shaun.