Need help with my magnetic tumbler

[Jerwei]

Hello,

I have recently bought a magnetic tumbler (from OttoFrei.com) after reading about how good and efficient a polishing machine it is. The first item I polished was a 22k gold plain ring. After 30mins of tumbling, the ring was dull and had a frosted finish or what others call an orange-peel effect. I then noticed on the product page of the website that says: "Not a Final Polish May leave behind an orange peel effect on smooth broad surfaces.", so I tried to polish smaller items like a few pairs of gold and silver earrings. They too came out looking dull and frosty. Other items such as bracelet and necklace came out okay but I find the finishing quality inferior to that of a rotary tumbler.

I've tried using liquid and powdered burnishing compounds, experimenting on different amount of water used and extending the tumbling time but to no success. I have seen videos in youtube and read online articles showing how bright and shiny a seemingly plain ring (among other jewelry) can be after it has been tumbled in the magnetic tumbler.

The good thing about it is that it doesn't remove delicate designs on the jewelry during the tumbling process and produces a very even finish.

So what did I do wrong? Why am I struggling to get a bright and shiny finish as advertised? How should a magnetic tumbler be used in conjunction with other polishing tools? Also, should I polish my now frosty-looking ring with Tripoli then rouge or can I just skip it and apply rouge instead?

Any help is greatly appreciated!

I will upload photos my work and comparisons upon request. Thanks!

[mizgeorge]

Did you pre-polish your pins? I find that a new batch of pins need polishing on their own (or with a few bits of scrap) for several half hour sessions to just dull the ends a little, especially if they're the slightly larger size that seems to be supplied with a lot of machines. I use very small fine pins, and these seem to work best, though they can occasionally get stuck in pieces with very fine detail or chain.

I never need to do more than a quick final burnish with rouge equivalent, and usually just a jewellery cloth is enough to get a very high shine on pieces that have been through the mag.

[Dennis]

Are you still using the Bumblebee George, or have you upgraded now? Are the fine pins the original ones which came with the Bumblebee? Regards, Dennis.

[mizgeorge]

I have three bumblebees now Dennis. I looked at getting a single larger machine, but I use them such a lot that it made more sense at the time to have several on the go rather than having to wait between loads. I will get a bigger one sometime, but I don't mind hand finishing large pieces - it's the little fiddly stuff that works so well in the little magnetics, which will happily take up to bangle size. I have modified them a bit with sugru so that containers sit better on the base.

I don't like the pins that come with them though, and use the fine ones from Manchester Minerals - http://www.manchesterminerals.co.uk/...91.html#SID=26

[Dennis]

Thanks George.

[ShinyLauren]

I'm with George on running the pins with scrap a few times first - it produces a much better finish. I ran mine with brass castings, which took the sharpness off the ends really well.

[caroleallen]

I use one of those small locking plastic food containers on my bumblebee as I found that the lid on the container it comes with comes off when the contents warm up. I don't use it a great deal though as I can't always get the finish I'm looking for.

[Jerwei]

I did polish the pins for about 2 half-an-hour sessions, albeit without scraps. Solution became dark and replaced with a new batch of water until water ran clear. I'm using Best Built Mini Magnetic Tumbler with adjustable speed. I realized the original pins was heavily magnetized from sitting on top of the tumbler the whole time during shipping, which took more than a month to arrive, so I replaced them with new ones I bought separately. Did a pre-polish, then with the ring. Same result. The fresh batch of pins were magnetized too after just a session of pre-polish, but not as much as the first.

22k Gold Ring with a frosty look (which isn't that bad but not what I'm looking for)


Two identical bracelets. The one on the right was tumbled in a rotary tumbler and the other in a magnetic tumbler. There is a clear difference.




Tumbler I'm using


I haven't had any problems with the lid coming off and the container sits pretty well on the machine.

I would like to see your magnetically tumbled pieces, if you don't mind.

[ShinyLauren]

There's a before and after shot of some rough castings of mine on this thread: http://www.cooksongold.com/forum/sho...?t=5828&page=2

[Jerwei]

Ah yes, I see your pieces came out frosty looking too. But that was very impressive considering the pre-polish state of the pieces. A rotary tumbler would get them to a mirror finish. I should work on my pins to smooth the edges further.

Few more questions if you don't mind. Which is a better soap compound for magnetic tumbler, burnishing liquid or burnishing powder? The liquid soap I'm using turned the solution dark after 15 mins of pre-polish while the powdered solution remained clear. The powdered soap I have is an all purpose type.

The magnetic pins I'm using are of the same size (0.3mm x 5mm). The original pins that came with the tumbler was a mixture of 0.4mm and 0.5mm. Isn't the smaller the pins, the better? And is a mixture of sizes better than all of the same size?