Used Rock Tumblers
Should I Buy a Used Rock Tumbler?
Lots of people think about purchasing a used rock tumbler to save money. A used machine can be an intelligent purchase if you get a fair price and know how to determine if the tumbler is in good running condition.
|Avoid tumblers that are “no longer manufactured.” If you buy an obsolete tumbler and need a belt, or a bearing, or a motor you will be out of luck. Lots of people contact us looking for ancient tumbler parts. We don’t have them. We don’t know where you can get them.|
What Type of Tumbler Do You Need?
It is very important to purchase a tumbler that is matched to your budget and to the number of rocks that you have to tumble. If you don’t need an extra large tumbler it is probably not a good idea to buy one – even if you get a fantastic deal on a used machine. Large tumblers are expensive to operate. For example, a 12-pound capacity tumbler uses one pound of grit for each grinding step. That large tumbler will cost a few dollars a week to operate – just for the grit. You will also have an expense for rough and electricity. (See our article on the costs of running a rock tumbler.)
If you have lots of rough to tumble, a tiny tumbler is going to frustrate you. If you have twenty pounds of rough, a tiny tumbler that processes two pounds will take nearly a year to work through your rough.
Examine the Cord and Motor
First check the electrical cord and motor case to make sure that they are in good condition. Any burn marks, melting, cuts or splices are a sign that there might be a problem. I would not buy a tumbler that might have an electrical problem. I would also reject a motor that has rusty metal parts or is full of dirt.
If a used tumbler needs a new motor, I would buy a new tumbler instead. A new motor will cost between $40 and $100. I would rather apply that money toward a new machine.
How Well Does it Run?
When buying a used tumbler it is very important to see if it runs well. Place the machine on the floor, plug it in and let it run until the motor becomes hot to the touch (this is normal – most tumbler motors run hot to the touch). Potential problem signs are: excessive noise, squeaks, grinding sounds or a burning smell coming from the motor. Look for the source of the noise to see if the machine simply needs lubrication or if new parts are required. (See our article on rock tumbler noise.)
Place a barrel full of rocks on the machine. The motor should not strain and the barrel should turn smoothly. Problems here might signal a bad motor, bad barrel, poor alignment, or bad bearings. Some of these are easy to fix. Some can cost a lot of money.
Examine the Rubber/Plastic Parts
Rubber and some plastic parts deteriorate with age or with storage in hot or cold environments. Are the rollers in good condition? Are the bearings clean, smooth-working and free from cracks?
Is the rubber barrel in good condition? Remove the lid and squeeze the barrel. When you squeeze it do you see cracks opening up in the rubber? If the rubber is stiff or cracked it might be old. Examine the walls, bottom and lid to see if they are wearing thin. Carefully check the rubber where the lid seats and seals. You don’t want a barrel that leaks!
Be Careful of “Vintage” Tumblers!
Lots of people buy vintage rock tumblers at yard sales or online auctions. They think that they will clean them up, replace a couple of parts and have a brand new machine. Then they learn that it is impossible or very difficult to get replacement barrels, bearings, belts, motors and other essential parts.
If you buy a tumbler that is not currently being sold in new condition, expect to have trouble buying replacement parts.
Tumblers made in the early 1970s or older usually have barrels made from a paint can or molded plastic. These make an enormous amount of noise and usually don’t last very long. New, rubber tumbler barrels may not fit these machines or fit them poorly.
Used Tumbler Supplies
If your used tumbler comes with some rough rocks or ceramic pellets they will probably work fine. However, if the tumbler comes with a package of fine grit or polish that has been opened you should assume that they are contaminated. Trying to get a good polish when your fine grit or polish is contaminated is a waste of time. I would throw them out, or be willing to waste a couple of weeks testing them on low-value rough.
Toy Tumblers Have a Very Short Life
Finally, rotary rock tumblers that have a plastic barrel are toy tumblers. These tumblers might survive tumbling a few batches of rocks. If you buy one in used condition, don’t expect it to last very long. (We don’t sell toy tumblers in new condition because they get lots of bad customer reviews and they don’t last very long. The tumblers that we sell are hobbyist or commercial quality.)
All of the rotary tumblers on the market today that are worth buying in used condition have barrels made from rubber or metal. Tumblers made by the following companies are hobbyist or commercial models that might be worth buying in used condition: Lortone, Thumler’s, Lot-O-Tumbler, Covington and Diamond Pacific. These tumblers are quality machines and you can usually get replacement parts for models that are currently manufactured.
Where to Buy a Used Rock Tumbler
Our highest recommendation for a place to buy a used rock tumbler would be a rock shop where new rock tumblers are sold. Sometimes these shops accept used tumblers as trade-ins on new tumblers. Here you will probably be buying from a person who knows about rock tumblers and is not trying to dump a lemon on you. Another good place might be a rock and mineral club swap meet where members sell and trade their excess items. Here you will likely be buying from someone interested in the hobby who is selling a machine that has been taken care of.
Places to be very careful when buying a used rock tumbler are yard sales, flea markets and online auctions. At these places it can be very difficult to get information about the machine – it was yanked out of an attic last week and now it is for sale. It can also be impossible to examine and test it properly.
Don’t Pay Too Much!
We see lots of people paying too much for used rock tumblers. We collect vintage tumblers and see the prices that they are sold for in used condition. Buyers often bid the price up to an amount that is more than what an equivalent new tumbler would cost. Sometimes they pay a lower price, but then the cost of replacement parts will drive their total cost to higher than a new tumbler.
If you are buying a used machine you should be paying way less than the cost of an equivalent new machine. These machines have a limited life and if the machine that you are buying is 1/2 worn out you should be paying way less than 1/2 current retail.
Finally, we would not purchase a used tumbler that is no longer made. If you buy one you will quickly find that replacement parts are no longer available. The first time you need a lid, a bearing, a belt or a barrel your tumbler will be inoperable.
Good luck if you are buying a used rock tumbler. We hope you get a great machine and a great deal.