Rotary Rock Tumbling: Get Rolling
Part 5 of 6 – It’s time to get rolling!
You’ve done it! You have made through our first four sections on getting started, choosing material, loading the barrel, and adding water and grit and not it’s time to fasten that barrel lid in place and start rolling. Before you do please make sure to read through this list of pro-tips, tricks and advice which starts off with a ‘generic’ four stage tumbling cycle packed with specific information from our expert rock tumbling community members.
Before we get to the “Get Rolling” list of pro-tips, tricks and advice, what follows is a description of a rotary rock tumbling cycle through which a batch of rocks comparable to agate or jasper can be reliably transformed into gorgeous polished rocks every time. Please consult a recipe specific to the size of your tumbler for the actual measurements of how much grit to add to your barrel at each step of the cycle.
- Stage 1 – Course grind with 60/90 SiC with no time limit.
Check the rocks and recharge the grit weekly until every rock in the barrel is ready to move on free from pits and major cracks that will be impossible to clean the grit out of. Don’t be afraid to cull out problematic rocks during this cycle. Much more is said about stage 1 rough grinding in the tips and advice below, so take the time to keep reading for now.
- Stage 2 – Medium 120/200 SiC for one week.
Check the rocks and remove any new problem rocks that have appeared. Medium tumbled rocks that are ready to move on should have a very finely abraded (dull) surface and they should feel very smooth but not look it. If you did a very careful job on stage 1 getting every rock in the batch ready to move on, you probably won’t need to keep rolling on stage 2 after one full week. That being said, with the amount of rock material lost on this step being substantially lower than on stage 1, don’t be afraid to recharge grit and keep going if you think it needs it.
- Stage 3 – Fine 500 SiC for one week.
Check the rocks again and remove any new problem rocks that have appeared. Fine tumbled rocks of a hard material like jasper or agate should be very smooth and starting to show a patchy shine. Again, never be afraid of recharge and go another week if you think they are not ready.
- Stage 4 – Polish with *AO powder for one week.
Check the rocks and if you have followed these steps carefully and patiently you should be looking at a beautifully polished rocks that have reached the full potential of the material.
*As a side note of caution, certain materials do not respond well to aluminum oxide (AO) polish so you might have to venture out of your comfort zone and experiment with other polishes such as tin oxide or tripoli for the final polish.
What follows next in no specific order is a bullet list of pro-tips, tricks and advice on the subject of getting your rotary rock tumbler rolling, contributed by the Rock Tumbling Hobby Forum community.
Now that your tumbler is happily rolling, lets take a look at the final Part 6 of the series, Rotary Rock Tumbling Cleaning Up, and start thinking ahead to what you will need to make your final cleanup efficient and maybe even enjoyable.
If you would like to offer feedback about your own experiences, pro-tips, tricks and advice, please post in this thread in the Rock Tumbling section of the RTH Forum, and they might eventually make it into the appropriate category in this article series.