Vibratory metal polishing- school me

I have a lot of bronze sand cast parts needing to be polished. I have sanded them smooth, and thought this would be an excuse to buy a vibratory polisher. I threw in a sample that I had already polished on one side so I could better see how much the abrasive was cutting. After 1.5 hours in 220 grit, there is no difference in either the sanded side or the polished side.


Do I need to let it go for many hours? Am I expecting too much? I thought this would make final polishing easier and also get into those cracks and crevices where it’s hard to reach. I wasn’t expecting to get them shiny- I was going to vibrate them through 1000 grit, then hand sand to 3200, then buff. My expectation was just to even out the scratch pattern a little more at each level of grit. I’m seeing nothing at all. I could go longer, but thought I would ask here because I thought after 1.5 hours there would be at least some difference.

Here is a similar unit to mine. I didn’t pay that much, but looks the same.

Attachment 402467

Machines like this are for deburring. Polishing requires tumbling with liquid and abrasive and only works for convex shapes. I do this kind of job with abrasive laden rag wheels on a pedestal grinder in increasing grades, then sisal wheels, and finally soft cloth wheels with polishing compound. This gets you a mirror finish to either leave as is, or go on to nickel and chrome plate or whatever other finish may be required. Cheers

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Originally Posted by Wayne Lomman

Machines like this are for deburring. Polishing requires tumbling with liquid and abrasive and only works for convex shapes. I do this kind of job with abrasive laden rag wheels on a pedestal grinder in increasing grades, then sisal wheels, and finally soft cloth wheels with polishing compound. This gets you a mirror finish to either leave as is, or go on to nickel and chrome plate or whatever other finish may be required. Cheers

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Thanks for the reply. That’s what I have always done, but was hoping this would help get into the areas that are hard to reach. Well- now I have a vibratory polisher for maybe cleaning things? It was a fairly cheap experiment. I will chalk it up as a learning experience!

I think that it depends on what you are polishing and the material that you polish with.
I do some reloading and use a vibratory polisher for the brass cases.
Now that you have one, you can experiment with different media and it may require several progressive stages.
Regardless, I would rather have a polisher do the work than sit there at a grinder if possible.

Chris

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Originally Posted by Chris Schoenthal

I think that it depends on what you are polishing and the material that you polish with.
I do some reloading and use a vibratory polisher for the brass cases.
Now that you have one, you can experiment with different media and it may require several progressive stages.
Regardless, I would rather have a polisher do the work than sit there at a grinder if possible.

Chris

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I'm not even sure what the media is, but I ordered 220, 500, and 1000. I'm polishing bronze. I was just hoping to get to the cracks and crevices more than anything, so no big deal to do it with a sander and buffer. I expected probably this wasn't going to have great results, but I didn't expect to see no visible change with the 220.