Tumble and Polish

Are the double barrels not turning on your rock tumbler? Is the drive shaft turning, belt tension is fine but the barrels just won’t turn or turn a few cycles and then just stop? Keep reading to find the solution that worked for me!

I mentioned in a earlier post that thanks to a barter swap I’m the proud owner of a QT66 tumbler. A QT66 is essentially at QT12 but instead of one 12lb barrel it has two 6lb barrels! Unfortunately I experienced some difficulty with getting the barrels to turn. I tried everything from cleaning the drive shafts, oiling both shafts, changing the drive belt, tightening the drive belt but nothing solved the issue. I even swapped the barrels with my QT12 and even though the 12lb barrel would turn on BOTH tumblers, the 2x6lb barrels would not. Ugh! But at least that narrowed the issue down to the barrels! There wasn’t enough friction between the barrels and the shafts so I lightly sanded the barrels. Nope, not the solution. I lightly sanded the drive shaft and the other shaft. Nope, not the solution either. Ugh!

Temporary Solution

Thanks to my friend Google I found a reddit forum with the suggestion of using rubber bands around the barrels. Thankfully I had a couple of rather large rubber bands in the drawer. On they went and it worked!! Yay! However, the rubber bands eventually wore out and I was back to square one! While I searched again for a more permanent solution I kept using a rubber band around each 6lb barrel and kept a close eye on the wearing of the band. They usually lasted 2-3 days.

More Permanent Solution for Barrels not Turning

After more google searching I did find a more permanent solution on a rock tumbling hobby forum. First I thoroughly cleaned the tumbler with WD40 as suggested to remove all traces of oil. I do think that when I oiled the drive shafts when I first got the tumbler that some of the oil may have inadvertently drifted onto both shafts. I purchased some 3in1 oil from the local Mitre10 store and very carefully and sparingly applied a drop of oil on both ends of the shafts and on the outer bearings. Then I got out my dremel, used a sanding bit and gently sanded the rubber on both shafts. That worked a treat! No more rubber bands needed, no more non-turning 6lb barrels.

I do love using the 12lb barrel for Stage 1 (on repeat until smooth enough to make a batch of stones ready for Stage 2 – 220grit) but I don’t really like using it to take a batch of stones from start to finish. This is mainly because a 12lb barrel full of stones is really heavy, and there’s so many stones to deal with especially when it comes to weighing them! So I am very happy to have two working 6lb barrels now!

These stones are from a fossick at Gemstone Beach with my fellow rockhound and good friend JP during his visit down south earlier this year – 7 March 2024 to be exact.

Batch 71: 6lb Tumbler 1

I decided to add back in the stage that uses 600grit. The polish/shine finish of the last few batches of stones have not been that great and I know that I have been pedantic about only filling the barrel ⅔ full, filling the barrel with water to just below the top of the stones, adding cushioning material when needed and closely inspecting stones not allowing them to progress to Stage 2 until I’m completely satisfied with their smoothness, lack of pits/scratches etc.

By adding the extra stage back in, the lightness of the 600grit will ensure that the grit will take care of any composite stone surfaces that just need that extra bit of grinding and/or smoothing out without losing too much more of the stone itself. Apart from lengthening the amount of time, there’s nothing to lose by doing so and hopefully gaining a better polish and/or shine.

Ready to Polish

There was room for more stones in the barrel so Batch 70 hitched a ride for polishing. Three stones were removed from Batch 71 as they weren’t ready to go to the polish stage.

Polished Stones of Interest: Batch 71

There were lots of stunners to choose from in Batch 71 and I cheated a little by included 2-3 in one shot!

Batch 71 | 6lb Tumbler 1 | Gemstone Beach | 30 June – 23 August 2024