Post by jamesp on Jul 14, 2016 10:32:43 GMT -5
I use SiC for grinding really coarse and chunky stuff, but I got a box of AO 80 from Harbor Freight for really cheap and I have been using that for course stuff that does not need much shaping, like river rock that needs a good grinding but not serious shaping. I run it with soap in one of my larger rolling tumblers for 10 days w/o adding any more AO, and it gives me interesting results. Some stuff does not work so well and needs another round of coarse AO or even SiC in the large 12# or 15# rotary. Other stuff winds up ready for 220 SiC, and some stuff is near polished and I move it up to 600 SiC, both of which I run in my one of my Mini-sonic vibes for 2-3 days w/o any soap or rubber bumpers(soap tends to foam up too much and the rubber bumpers are pushed to the top and out of the spin cycle by the virbator). Then I run them with 1200 AO polish in the smaller roller tumblers for a week with soap and rubber buffers that I made from cutting roofing rubber into 1/4" pieces. Then I burnish them with soap/bumpers for a few hours. Slag glass and obsidian I then run in micron AO for a finer polish.
I also use high quality quartz sand as a pre-clean to cut off the crud and dirt from rocks before I decide whether I want to tumble them or not. I got a 5 gallon bucket of sand from Carmel beach last year that works well for that. There used to be what was called the "sand plant: at Pebble Beach where the Spanish Bay resort and golf coarse are now. They used to get the sand there to use for making high quality glass, as well as missile heads at Lockheed. "They" say not to tumble with sand, but I have had good results using it as a pre-tumble media.
Question for the OP, why the sugar added in some of your runs? I never tried that. Simple syrup?
I wore out one Mini-Sonic tumbler barrel using coarse SiC, and they are not cheap. So I do not use coarse in the vibe tumblers any more. The vibes also push too much polish into the cracks and voids for me so I prefer to polish using roller tumblers with soap to reduce the polish push-in and the bumpers to reduce the rock impact.
i have greatly simplified my tumbling method oregonborn.
Getting great polish.
But only tumble agates and hard rocks.
Mostly use SiC 30 in rotary, Ao 500 and 14,000 in vibe. Not so particular cleaning other than good wash with water.
call it lazy, but it is working.
Tumbling breaks grit down well enough to skip a lot of intermediate grits, my findings.
Using extended cycles at last coarse grit run is converting SiC 30 to 500-800. Vibe ready.
Yes, vibe do pack crap in the crevices, especially Borax when on the dry side. that does irk me.
Sugar does dissolve far better than Borax, nice feature.