doublet83
starting to spend too much on rocks
Member since March 2016
Posts: 118
|
Post by doublet83 on Mar 9, 2016 16:06:25 GMT -5
Hi, new to the forums but I have been searching and reading up on tumbling for the past few months.
I am wondering how necessary it is to use a decent amount of small material in the coarse grit stage? The material I have purchased online typically consistent of 1 to 1.5 inch stones. Am I just prolonging the stage 1 tumbling process by not using enough small material? Or is it that without the small material the tumbling process has a harder time smoothing out the nooks and crannies of the stones?
|
|
|
Post by Jugglerguy on Mar 9, 2016 16:34:16 GMT -5
Picture a room full of basketballs. They'd only touch in a few spots. If you added in some baseballs, golf balls, and marbles, there would be a lot more surfaces contacting. When tumbling, grinding can only happen when grit is sandwiched between two rocks. The more contact you have, the more grinding can take place.
If you have some small rocks that you want to tumble, those are perfect to throw in the mix. I don't usually have that many small rocks, so I use small pebbles I pick up on the beach. If you can't find free rocks, try some small pea gravel for landscaping or for use in an aquarium. Just be careful to buy something fairly hard. You don't want to use something like limestone that is so soft that it will wear away to quickly.
|
|
victor1941
fully equipped rock polisher
Member since November 2011
Posts: 1,979
|
Post by victor1941 on Mar 9, 2016 18:18:58 GMT -5
I think that smalls are extremely important in vibe tumbling. Smalls not only move the grit but also keep the material from banging together and causing other problems. I use trim saw scraps for fill and give them to schools after the final polish.
|
|
|
Post by johnjsgems on Mar 9, 2016 20:00:28 GMT -5
I love the ball analogy. I'll have to remember that when explaining to newbies at shows. I guess you have the answer. Not necessary but very helpful. Pea gravel is pretty cheap. Most people use ceramic media. Saw trimmings useful too and usually pretty when finished. Whatever smalls you use will speed up the process, act as filler, and cushion. Remember to keep barrel about 3/4 full throughout so some filler will likely be needed after round one. Unless you keep adding step one rocks until you have a full load ready for round two.
|
|
70karmann
starting to spend too much on rocks
Member since February 2011
Posts: 190
|
Post by 70karmann on Mar 9, 2016 21:12:45 GMT -5
I use all sizes in each tumble.
|
|
Fossilman
Cave Dweller
Member since January 2009
Posts: 20,681
|
Post by Fossilman on Mar 9, 2016 22:53:01 GMT -5
I use all sizes of rock material in each tumble-the smalls make all the difference in the world.........Pack them in with the bigs.............
|
|
doublet83
starting to spend too much on rocks
Member since March 2016
Posts: 118
|
Post by doublet83 on Mar 10, 2016 9:03:16 GMT -5
Ah, thanks for the responses. I think I've read somewhere that 20% of the material in stage one should be smalls? I felt my results have been pretty good without using that many, but I'll have to try using more.
|
|
|
Post by johnjsgems on Mar 10, 2016 10:56:01 GMT -5
When I first started tumbling I did several very successful loads with no filler. Then I read about using plastic filler to prevent chipping. I blew it off as a new "expert". Next batch was pigeon blood agate and it all got beat up very badly. Lesson learned. I hated the plastic and switched to ceramics. As far as how much, a good rule of thumb with ceramics anyway is fill barrel 2/3 full with rock and bring up to 3/4 with ceramics (or other small filler). You can adjust the ratio depending on what your rock mix is.
|
|
doublet83
starting to spend too much on rocks
Member since March 2016
Posts: 118
|
Post by doublet83 on Mar 13, 2016 10:30:05 GMT -5
Broke off some cheap mixed rock I got off of Ebay to create some smalls. For some reason, this jasper I broke with a hammer was literally 10 times easier to break than a Brazilian I had been trying to break before. Not sure if that rock was just inherently much more brittle, or maybe it had already been crushed and had more internal weaknesses.
|
|
|
Post by Starguy on Mar 15, 2016 19:28:25 GMT -5
doublet83watch for sales of small agates online, at Rock shops and when collecting yourself. I try to maintain a future tumbling supply of 50% smalls to 50% med-large. The smalls help smooth the larger stones in coarse and they are even more important in the finer stages. It sounds like you are working out a good recipe. I can't wait to see some photos. Later
|
|