Using a rock tumbler isn’t too difficult so anyone can figure out the basics. Nevertheless, even veteran users may run into problems from time to time. No one knows everything. Therefore, it is pertinent to continue working hard to learn how to use your tumbler as effectively as possible. Otherwise, you may end up with broken stones or stones that haven’t been adequately polished.
By taking specific steps, it is possible to avoid these problems and get the best results.
Breaking The Stones
First, some users are going to encounter broken stones. Caution has to be taken to avoid severely damaging the stones. Unfortunately, stones can be broken during any stage of the tumbling process. In some cases, it is impossible to avoid breakage because the stone may already have internal cracks. Those cracks will likely worsen as the tumbling continues and the rock will break.
However, some issues that can lead to broken stones can be rectified. First, the user needs to be very careful when picking the right speed. It is also vital to tumble for a perfect amount of time without under or overdoing it. The number of stones being tumbled at once can also lead to problems. In particular, there might not be enough stones in the container.
Instead, the rocks will have more room to move so they’ll hit each other with more force. Consider these things when preparing the tumbler to prevent your stones from getting damaged.
The Stones Aren’t Polished
Once the tumbler has finished running, you may notice that the stones aren’t polished. If the stones are hazy, this means that the tumbler didn’t polish them enough. Ultimately, this can be caused by a handful of issues. It is common for beginners to mistakenly use pre-polish grit which isn’t going to provide the desired results. The abrasive material might’ve been left from the prior stage of the tumbling process. Some rocks have pits, making it slightly harder to polish them using a tumbler.
Another reason that your stones aren’t polished is that you’ve tried to polish mixed stones. You might’ve mixed hard and soft stones in the tumbler. Make sure you’re tumbling the same type of stone and that you fill the barrel completely.
The Edges Are Polished
You may end up with stones that only have polished edges. While this is a good start, you’ll want the entire stone to be polished. Thankfully, you should be able to fix this problem easily by repeating the pre-polish tumbling stage again. However, you first need to identify the source of the problem. Usually, this happens when someone doesn’t fill the barrel enough.
Add more filler to ensure that the threshold is met. While you don’t want to overfill the barrel, it has to be filled enough to provide a satisfactory, uniform polish.
Centers Polished Only
On the other hand, the stones may only be polished in the center. It is common for this to happen because you didn’t use enough additives so the material wasn’t abrasive enough. Alternatively, the slurry should be thicker. Look at the edges of the stones to see if they’re chipping. If you see noticeable chipping, you’ll need to coarse-grind the stones again for at least two days.
Once you’ve done this, you can complete the other steps while using more additives and thickeners. If the edges are hazy or there is minor chipping, an intermediate grind is required.
Not Completely Polished
The tumbler may not have completely polished the stones. While it is shiny, the appearance isn’t satisfying. You might’ve rushed the intermediate grinding phase or the pre-polish tumbling stage. Otherwise, you might not have cleaned the stones and barrel thoroughly enough after the last stage was completed. Once you’ve cleaned these things again, try repeating the last step. It should be enough to provide a better finish.
Flat Spots
If something goes wrong, you might end up with flat spots. This happens when the stones are hitting the wall of the barrel instead of being tumbled and polished. If this is what you’re dealing with, consider using a faster tumbling speed. Otherwise, you can add more material to the barrel.
Scratched Stones
Stones can develop scratches if there are too many slabs. For the best finish, you should only use up to 20% of slabs in any tumbling barrel. Be sure to use a softer medium.
Developing Blisters
Fractures and blisters can develop when tumbling certain materials. This tends to happen more often on crystalline stones. The problem might be that the stones are hitting with too much force. You might not have added enough filler or the solution may not have enough viscosity. It may be possible to get rid of the blisters, but you must return to the rough grinding phase. Once the fractures are gone, be sure to handle the stones carefully.
Pieces Chipped Out Of The Center
A small piece might’ve been chipped out of the center of the stone. The most common cause is using a rotation speed that is too high. However, this can also happen when someone attempts to tumble a barrel full of large rocks. It is best to use rocks of different shapes and sizes. The problem tends to happen more when using a vibratory tumbler. The stones can be rough ground until the chips have been removed. Then, the next steps should be completed after increasing additives.
Switch to a slower speed if possible. If you’re using a vibrating tumbler, use the lowest setting so the process is gentler.
Overall
There is no guarantee that the tumbling process is going to go smoothly. Nevertheless, more problems can be avoided. First, it is important to find out what is wrong with the stones. Then you can find out why you’re experiencing that problem. Even veterans will run into these problems from time to time because they don’t fill the barrel enough or they’re not using enough media. The tumbling process can be completed again with the correct settings and materials. Just make sure that the parameters are perfect this time because tumbling too much can cause severe damage.