The first thing I’ll say about tumblers is to get one! If you only work in gold fill and niobium, then maybe you don’t need one, but for any material that tarnishes (sterling silver, copper, and jewelry brass) a tumbler will be your best friend. There are many types of tumblers available, but the main difference you care about is the material of the barrel.
Rubber barrel tumblers are very common, and come in a range of capacities and barrel counts. I do not recommend using rubber barrels. The reason they exist is to tumble rocks. Rock tumbling requires a sequence of really serious grit in the water to abrade the surface of the stones. A hard barrel would also get abraded, so rock tumblers are made from rubber. But if there’s no grit, there’s no need for a rubber barrel. Avoid it if you can, because the rubber breaks down over time, eventually leaving a gentle grey skunge all over your pretty jewelry.
Important safety tip: never, ever use an ex-rock-tumbler for chainmail. It’s impossible to clean out all of the grit, and those tiny leftovers will wreak havoc on the surface of your metal.
Hard plastic barrel tumblers are a better choice for tumbling metal. It doesn’t matter whether the barrel is turned by a shaft or by spinning rods. What’s important is the hard plastic that won’t degrade over time. At present, I don’t sell any tumblers, but I can recommend AE Aubin as a maker of bullet-proof shaft-driven tumblers. These are the tumblers that I use in my shop. They’re a little more expensive, but I’ve been beating the stuffing out of mine for over a decade and haven’t managed to kill one yet. If you’re making chainmail just as a hobby, then you don’t need the industrial-strength version. You can check your local craft store for hobby tumblers, though they might not be very robust. Rio Grande sells a Dura-BULL rotary tumbler that ought to be long-lasting, though I don’t have personal experience with them.
You might encounter vibratory tumblers in your search. While there’s nothing wrong with using these for chainmail, it’s definitely overkill. Vibratory tumblers work faster than rotary tumblers, so a job that would normally take days can be completed in hours. But your chainmail only needs to tumble for minutes, not days. In my opinion, it’s not worth the extra expense for such a minor time savings.
Stainless steel shot is more expensive than regular steel shot, but it’s so worth it. Rust is not your friend. Stainless shot is available in a range of shapes – the shape isn’t crucial when tumbling chains. The shot acts like a zillion tiny hammers, planishing and smoothing the surface of your work, which can be helpful for minor scuffs. But the main reason that I tumble jump rings and jewelry is to degrease them and remove tarnish.
There are lots of specialty products to add to tumbler water, but I nearly always use just Simple Green and/or distilled vinegar. Simple Green is great for cutting grease, and I like that it’s environmentally friendly. Freshly cut rings are covered in cutting lubricant. Jewelry worn on a sunny day is covered in sunscreen. These are both jobs for Simple Green. You can use other soaps (I know that Dawn is a popular one) but if your tumbler has a rubber barrel it is important that your soap not contain any citrus (no lemon-scented dishsoap) because it will accelerate the deterioration of the rubber.
Vinegar is great for eliminating tarnish from copper, brass, and sterling silver. Just a few squirts in the water (it doesn’t take much) lowers the pH enough to eat away at the tarnish, and the polishing action of the stainless shot smooths the etched surface back to a mirror gleam.
In a perfect world, our rings would have no marks of any kind, and the ends would line up flawlessly. While focused practice will get you close to that ideal, “perfect” is only for fairy tales and math textbooks. Abrasive media is a handy tool to get your work a little bit closer to perfection. Unlike stainless shot, abrasive media actually removes material, lightly sanding the surface of your work. And just like regular sandpaper, you start with a coarse grit and move your way through finer and finer grit. The final step is to tumble your abraded piece with stainless shot to hammer it smooth again. Is abrasive media a necessary step? Absolutely not! And if you have any gold fill or niobium in your piece you shouldn’t abrade it. But it’s a fun option to play with, and the extra-silky feel that’s possible is very nice.
Important safety tip: Abrasive media is not a “magic fix.” Mis-closed rings and large dents will still be there after tumbling. Tumbling with abrasive media is only the final frosting after you bake a really good cake.
The bottom line? Get yourself a tumbler and some stainless shot. Ten minutes with a few squirts of vinegar in the water? Your jewelry will gleam!