Post by jamesp on Sept 24, 2014 7:00:36 GMT -5
Hi all,
Got a question for you guys regarding the recharging process with a rotary tumbler.
Assuming you know that none of your rocks are ready for the next stage, Is there any value In doing a complete clean out with new water & grit as opposed To just adding grit and letting the tumble continue?
Thanks for all your input.
Sak
I have been tumbling coral over and over for a couple of years in the rotary. It became routine and predictable.
Rio Grande agate too, also predictable. About the same recipe over and over. Always like to see the dirty slurry.
checking every day till it started. Once dirty the grind seems to take off. Never let it get pasty. But learned to
start w/water well below the rocks, or the grit seemed to wash off. If started w/the water level w/the rocks little
grinding occurred and water stayed clear and no grinding was happening.I suppose the slurry should be sticky enough
to pick up the grit and keep it stuck to the rocks.
Edit not sticky enough to stick to the rocks
thick enough to keep the grit from settling
Dirty water with rock particles suspended is heavy and will float the grit better, more efficient for a rotary.
Vibs circulate grit more efficiently. Probably why they do not need much grit. Vibs just different. And do not need much water to serve as a carrier.
Vib has every rock coated w/grit in 5 minutes if proper amount of water added. Suspension not an issue.
Coarse grind in the rotary tip:
The coral is harder than about all the Rio Grande agate.
But has a lot of soft limestone coating that quickly wears off and dirties the water unlike the Rio agate.
It gives about a 2 day jump on the Rio Grande agate each coarse grit change.
Adding crushed dry clay to the Rio agate at coarse grit change helped dirty the water immediately solving the problem.
Fine grits about stay suspended even in clean water. They are easy.
Coarser grits like 16 and 30 grit really need thicker slurry, much worse about settling and distributing well. Especially in a slower turning rotary.
Non-abrasive additives like non petroleum based thickeners help suspend grit particles such as sugar. Spreading
them more consistently throughout the slurry and lubricating the cutting action. Great for finishing steps.
Rotaries all about grit suspension