bcgal
noticing nice landscape pebbles
Member since March 2016
Posts: 94
|
Post by bcgal on Aug 18, 2016 17:54:35 GMT -5
Could you not just use a few tablespoons of fine sand as a grit in stage one of a tumbler?
what is a 60/90 grit made of? looks like fine sand to me
Anyone tried this before?
|
|
|
Post by Drummond Island Rocks on Aug 18, 2016 18:14:15 GMT -5
Could you not just use a few tablespoons of fine sand as a grit in stage one of a tumbler? what is a 60/90 grit made of? looks like fine sand to me Anyone tried this before? Commercial tumbling grit is made of very hard silicon carbide with a MOHS hardness around 8-9 which is harder then most rocks we tumble. Beach sand is much softer than most rocks we tumble at around 4-5 so it has no real grinding power. I sure wish it were as easy and cheap as using sand. Chuck
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Aug 18, 2016 18:21:55 GMT -5
Even pure quartz sand is mohs 7 and would have little effect. Tumbling abrasives are about 3 times harder than most of the rocks people tumble.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Aug 18, 2016 18:29:54 GMT -5
Could you not just use a few tablespoons of fine sand as a grit in stage one of a tumbler? what is a 60/90 grit made of? looks like fine sand to me Anyone tried this before? To expand on what Chuck said above: Playsand from home depot is ~equal to the hardness of the stones we mostly tumble. It wont assist in grinding much at all. If it did, we could just add our rocks to the barrel and tumble. No need for grit at all. I suppose pea gravel made from quartz materials will act as "fines" giving us the increased touchpoints during the tumble, but even then, this wont replace grit. Jugglerguy Rob, I remember a fantastic visual description you made a while back that helped beginners understand why fines are useful. Would you be so kind as to re post that description? eTa: and what jamesp simul-posted!
|
|
bcgal
noticing nice landscape pebbles
Member since March 2016
Posts: 94
|
Post by bcgal on Aug 18, 2016 18:51:27 GMT -5
ah I was just sitting here pondering, you know, the stuff you ponder while the tumbler is grinding away on week 3 with a batch of ocean jasper and pet wood (that my husband found with his lawn mower....) good for me, not so good for the blades on the mower. I use grits in case I forgot to mention. I did notice that my stage one grit was getting low so thats what started my pondering...and also waiting for my treasures...Perhaps I should instead buy a second tumbler or a third one...hmmm, you see my dilemma...maybe I should go rock hounding while I wait for my rocks..yes more rocks, all ponderings are solved with more rocks...HAHA
|
|
|
Post by Jugglerguy on Aug 18, 2016 21:59:55 GMT -5
Could you not just use a few tablespoons of fine sand as a grit in stage one of a tumbler? what is a 60/90 grit made of? looks like fine sand to me Anyone tried this before? To expand on what Chuck said above: Playsand from home depot is ~equal to the hardness of the stones we mostly tumble. It wont assist in grinding much at all. If it did, we could just add our rocks to the barrel and tumble. No need for grit at all. I suppose pea gravel made from quartz materials will act as "fines" giving us the increased touchpoints during the tumble, but even then, this wont replace grit. Jugglerguy Rob, I remember a fantastic visual description you made a while back that helped beginners understand why fines are useful. Would you be so kind as to re post that description? eTa: and what jamesp simul-posted! Scott, you're talking about having some small stones in with your batch? I think I described it this way: Imagine a room filled with basketballs. They would only touch in a few places. There would be a lot of empty space between them. If you added some golf balls to the mix, they would fill in some of the empty space and there would be more points of contact. Adding in some marbles would fill it in even more with more surfaces touching. The only way to having grinding take place is to have grit sandwiched between two touching rocks. With all big rocks there will be less grinding taking place, so your rocks will shape slower.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Aug 18, 2016 23:52:06 GMT -5
|
|
agatemaggot
Cave Dweller
Member since August 2006
Posts: 2,195
|
Post by agatemaggot on Aug 19, 2016 0:45:45 GMT -5
Check with any local company using a water Jet cutting machine. They use Garnet sand in them and can only use it once. Most of them will give you a bucket or more free as they can not usually dump it in the local land fill and have a small mountain of it hanging around their neck's ! It may work on softer stone and the price is right.
|
|
dottyt
spending too much on rocks
Member since July 2016
Posts: 305
|
Post by dottyt on Aug 19, 2016 1:20:01 GMT -5
Okay, this has got me wondering and inclined to ask dumb questions again. How about using sand to give the grit more contact with the rocks? Would that make the slurry too thick for the rocks to tumble well? Or would it just be too messy to bother with? I suppose there must be something wrong with it or people would be doing it.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Aug 19, 2016 9:34:57 GMT -5
Okay, this has got me wondering and inclined to ask dumb questions again. How about using sand to give the grit more contact with the rocks? Would that make the slurry too thick for the rocks to tumble well? Or would it just be too messy to bother with? I suppose there must be something wrong with it or people would be doing it. Try it! Won't hurt to try it. One of the fun parts of tumbling is to try different ideas and see the results. No matter what, you won't ruin the rocks!
|
|