Barrelling media

[cary1961]

Hi everyone,

I'm new to the forum and I have a problem. I've been trying to shine up some flat gold and silver pieces in my tumbler. I'm using a mixed fine s/s shot I bought from UKGE as it was far cheaper than Cooksons! It has two sizes of fine pins in it plus 2 sizes of balls, bicones and lozenges. The problem is that it is leaving a pin-prick effect on the flat pieces ie gold cufflinks, flat silver bracelet, flat silver dog-tag and a gold ring with flat surfaces. Am I using the wrong medium? It works fine on heavy curb chains. I have gone back to using my walnut shells for today until I can find out what to buy. Any advice will be much appreciated

[silken]

For larger, flat pieces it is not uncommon for the pin shaped media (designed to burnish all the little nooks and crannies in more complex designs) to mar the surface. I suppose you could (painstakingly) remove the pins and leave just the other shapes or (if you haven't already) you could try using radial discs. In my opinion, you can get a much better finish in much less time. Also, if you'd still like to tumble polish your pieces I find that adding a good handful of plastic shot (like plastic ball bearings) works great for practically every piece and reduces the likelihood of surface marks. Well, that's what I've found anyway. I always put some plastic shot in with my stainless steel mix.

Just out of interest, what burnishing compound are you using? Using a good one makes a massive difference to the overall finish.

[Dennis]

Large flat areas can also be polished using several grades of MicroMesh, available on line. These are grey rubbery sheets of graded abrasive, which can achieve a mirror finish. However in a professional workshop a jeweller would use a polishing lathe.

In the absence of a lathe a combination of radial disks as mentioned by silken, and MicroMeshh would work for you. Dennis.

[cary1961]

Thank you for both your responses. I used the barrelling method with s/s shot six years ago when I worked in a small jewellers shop with repair facility and I didn't have this problem then as far as I can remember. This is why I thought that the pins were the problem. However, I have today tried another flat silver dog tag with walnut shell and it looks even more pitted than the earlier pieces that I used the s/s shot on! I have my bench polisher so I think I'll use that with tripoli instead. Do you guys think that the s/s balls without the other shapes are better than the mixed shapes maybe? Emily; The plastic balls sound interesting - I haven't tried them before - thanks for that tip. I am using barrelbrite.