Advice on Metal Polisher Tumbler for Rusty parts

TimePiloteer

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I just bought a small 5lb vibratory tumbler and also an ultrasonic cleaner from Harbor Freight. I'm wondering about the best way to utilize these for cleaning and polishing small metal parts.

I've tried rusty screws and bolts in the ultrasonic cleaner - does not remove rust and does not polish. I think the strength of the ultrasonic cleaner is to remove dirt and grime from metal and plastic, and it seems to work great to clean old plastic pinball posts, and to clean old EM metal pinball parts/reels that have been caked with old lube and grease.

For polishing metal parts like rusty screws, post caps, carriage bolts, ball gates, what is the best way to maximize the vibratory tumbler?

What I've tried:

1. Soaking rusted parts in Metal Rescue. This does remove rust, but darkens and discolors many screws, washers, etc, and I can't get them bright and shiny.
2. Running them unsoaked in the tumbler with ground walnut shells. This does not remove rust very well. It does polish already shiny surfaces, but if there is any darkening or discoloration of the metal, it does not make it bright and shiny again. Also does not remove metal rust pitting.
3. Tried adding a little brasso into the walnut shells and tumbled again. No difference.

What media/soaking regiment works best to get all screws nice and bright and shiny again?

Thanks a lot!
 
Well.. I soak the rusted metal in white vinegar for a day or so depending on the severity of the rust. Then put them in the tumbler with Rust-Cutting Resin Abrasive from there.. it's green little pyramids. Then you can use the walnuts to polish as a final step.
 
You need to add a more abrasive component to the media when you run the tumbler. Brasso was a good start, but you need something more aggressive. And make sure you use the proper sized crushed media. And tumble long enough. Like 3 days long enough.
 
I've had good luck with Oxalic acid - it's a component in wooden deck cleaning solutions and you can find it at home depot. You need to dilute it before soaking or it will discolor the metal.

There's a chemical reaction with the rust - the rust turns black after soaking and brushes right off. It doesn't harm paint or even stickers.
 
Trade in both of those for a rotary wet tumbler (i.e., rock tumbler). I have two Lortone tumblers, and love them.

Wet tumbling is far more effective for small rusty parts. The trick is soaking them in vinegar for 12-18 hours to loosen up the rust, then wet tumbling against themselves in the vinegar, to knock all of the rust off, and out of the crevices.

Then follow up with a dry tumble in walnut shells (which you can do in the same tumbler) with a dab of metal polish, which removes the black oxidation and really makes them shine.

I actually wrote up a couple of detailed posts recently about my setup and methods, in this thread:

https://forums.arcade-museum.com/showthread.php?t=399245


They're also great for tumbling dirty tokens, which I tumble in a mixture of water, walnut shells, and dish detergent. Rinse through a strainer (so the shells fall through), dry them on a towel in front of a fan, and they come out amazing. You don't even need to dry tumble them afterwards.
 
Anyone have any advice on what rock tumblers are any good? What to look for? Is the dual drum Harbor Freight unit any good vs say a dual drum Lotrone unit?
 
I can't speak for the Harbor Freight, but I have two Lortones and a Thumlers, and the Lortones are better, IMO. The drum design is superior, and doesn't leak like the Thumlers does.

In my opinion, the Lortones are pretty much perfect. Quiet, compact, they seal well, easy to clean, simple, and you can still get complete replacement parts for them. (Not that you should need much, but I did but a new drum for my 2nd one, which I got the base for for a buck at a yard sale, missing the drum, which was like $25.)

My only complaint is that I don't have more of them (and bigger ones, for bigger parts). :) However, they do make industrial ones that get pretty big, and go up to $700 or so. Oh, the fun I could have with one of those...
 
Looks like I'll try the rust cutting media in the dry tumbler first, and if not satisfied, I'll swap it for the rotary tumbler.

Harbor freight sells the ceramic media, medium sized ceramic triangles. Does anyone know if those work in the dry vibratory tumbler? On the media's label/package, it specifically lists compatibility with the model number of the 5lb tumbler, but in the manual for the tumbler it specifically states that it does not work with ceramic media.
 
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