Our rock tumbling activities have been running at full tilt for the last 7 days, as we have had 9 barrels on the go. Something of a record for us I think, we even had to press an old machine that was given to us a long time ago into service.
Before I go on, a quick update on the new motor I fitted into one of the CR2 machines. It’s been a complete success, the motor has been running for over 7 days continuously without a glitch. I have noticed the motor does run “warmer” than the original, but aside from that nothing to be concerned about. You can read more about this in these two posts Post describing motor problems on CR2 and Fixing the CR2 rock tumbler with a new motor
As you can see in the video, we have 3 good sized piles of stones. Those on the right had completed the 80 grit stage. Those in the centre had just had 7 days in 220 grit while those on the left had just done 7 days in 400 grit.
Time to decide which tumbled stones are going onto the next stage.
As always, after giving the rocks a thorough wash to remove any residual grit, we have to sort them out. This means going through each pile carefully to decide which ones can go onto the next stage and which need another week back in the same grit again. Then load up the barrels with grit and water, seal them and set them tumbling for another week.
A little Rock Tumbling experiment!
Also in the video I tall you about a little experiment I am doing with a largish lump of flint. I am trying to see if the the 80 grit silicon carbide can be used to remove the chalk layer from the flint. As you will see, after the first 5 days or so the chalk has started to be eaten away, but I envisage this might take a while to completely remove it. My aim is to completely remove the chalk, then take the flint through the whole rock tumbling process. I hope it will take a good polish in the tumblers, it certainly does on the diamond wheels.
Finally we have a brief look at the pile that’s now completed the whole process and have just finished the polishing phase. We use cerium oxide as out polish and find it works well on most stones. Next these polished stones will be washed in clean water in ultra sonic bath and left to dry.
So there you have it, another week of rock tumbling completed, one that has borne quite a few fine fruits.