ejs
spending too much on rocks
Member since July 2008
Posts: 478
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Post by ejs on Jul 30, 2008 19:48:14 GMT -5
Greetings. I have been successfully tumbling rough cut rock in my Lortone 3lb. rotary tumbler. I am progressing one more step down the path by purchasing bulk rock (generally 1-2 pound large chunks, rather than already broken rough). I have some lapis lazuli, sodalite, tigereye, and watermelon serpentine, all purchased from Mama's Minerals.
Can anyone provide any tips on breaking up the rock in the best manner to tumble? I have a nice rock hammer (Estwing rock pick in both 22 and 14 ounce sizes), a chisel, and a hand-sized sledgehammer. I believe the general guideline is to wear safety goggles, cover the rock (towel etc.) and break it up into appropriate size pieces. Do I have the right equipment? Any suggestions for getting the most tumbler-appropriate size/shape pieces and the least waste? Should I just whack it, or use the chisel and/or rock hammer?
Any and all comments appreciated. Thanks!
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rollingstone
starting to spend too much on rocks
Member since July 2009
Posts: 236
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Post by rollingstone on Jul 30, 2008 20:11:29 GMT -5
Only whack the rock with the sledge or hammer as a last resort, ie, if it's just so tough that you can't break it smaller any other way... to much wastage and fracturing. With 1-2 lb rocks you should be able to bust them up pretty easily with a chisel and hand-sledge.
Get a good solid surface, I use a large cement "decorative" type rock like is used to make garden edges, then use the chisel and sledge to bust up the rock to any size you want. No towel, you want to see exactly what you're doing. Hit the chisel hard, soft hits tend to make the rock spall and flake, hard hits break it where you want it. Very quickly you will learn how that particular type of rock breaks, and you can then use that to your advantage to bust it up exactly how you want it. Every type of rock reacts a bit differently.
Safety glasses a must. Long pants probably advisable, I've taken lots of cuts on the knees from flying rock pieces.
Have fun!
Don
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rallyrocks
fully equipped rock polisher
Member since November 2005
Posts: 1,507
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Post by rallyrocks on Jul 30, 2008 21:46:30 GMT -5
You'll get some folks around here riled up pretty good by even the mention of going after gemstone material with a hammer and/or chisel.
For field prospecting and occasionally busting up found stuff, in my opinion, the use of a hammer is acceptable practice, but when it comes to dealing with higher quality materials, more controlled and less damaging methods really should come into play.
Lapis is one material that I would not want to smack with a hammer in just about any circumstance, it doesn't tend to work too well in tumbling either. Tigereye tumbles up nice but I'd much prefer to cut it on a saw rather than risk destroying it with a hammer
Have you given any thought to investing in a tile saw? I understand the $89 workforce model is no longer carried at Home Depot, but several other companies have low-cost equivalent models of wet 7" portable tile saws that give you a lot more control over how your stones get made smaller, and eliminate the problems of unwanted cracks and such.
Just something to consider before you go and spend too much money on fine materials....
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Sabre52
Cave Dweller 
Me and my gal, Rosie
Member since August 2005
Posts: 20,494
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Post by Sabre52 on Jul 30, 2008 22:06:38 GMT -5
I think Don and Rally have pretty much covered it. Like Rally says, I'd prefer not to hammer up expensive or hard to get material but on common stuff, I whack up the larger stuff fairly often. Serpentine might be the exception from the materials you've mentioned. It tends to be fibrous and multi-hardness making it a prime candidate for splintering or cleaving into unusable junk when whacked and a very difficult material to tumble too.....Mel
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catskillrocks
fully equipped rock polisher
Member since July 2008
Posts: 1,270
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Post by catskillrocks on Jul 30, 2008 22:49:39 GMT -5
For what it's worth, the $89 tile saw is still available at the Home Depot in our area. I don't think that it is going away any time soon. I might be wrong. But I work at the Kingston Home Depot in New York. Awhile ago I had read posts about it being discontinued. I checked it out at our location but it is still active & is a good seller.
At any rate, I would agree with the others. Some rock can be hammered, but in doing so can actually cause fracturing. The tumbled piece will be fine but will have these "cracks" in them. If you can get your hands on one of the popular HD Workforce Tile Saws you would be able to cut most of the size rocks you mention ( 1-2 pound) into tumbling stock. Good Luck.
Don
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Post by deb193redux on Jul 30, 2008 23:20:57 GMT -5
Even making a 1" deep cut with the tile saw and then putting the chisel in the cut can result in much more controlled production of tumble rough.
The collection yo have is sorta difficult to tumble material. Some tigereye has fibers pop out in tumbling, while other pieces do just fine. The serpentine is a little softer, but so is sodalite, so you may be OK. The lapis can have metal inclusions and these may unsercut when tumbling.
The best starter material is good hard agate and jasper. If you have already done a number of loads, then go for it. Just be aware you are describing a more challenging batch.
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lparker
fully equipped rock polisher
Still doing too much for being retired!
Member since March 2008
Posts: 1,202
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Post by lparker on Jul 31, 2008 9:13:23 GMT -5
The other plus in slabbing is you have better control over the final shape of the rock. I personally don't think I'd tumble lapis anyway, but you can get some nice wire-wrapping pieces if you pre-shape it, you won't waste as much material, and might even get a few extra bucks by selling it so you can buy more rock.
Whatever you do, and some will disagree, don't have any pieces larger than 1 1/2" (slabs) or 1" (chunks) in your 3 lb'er. Slabs will finish faster than rough because the edges are smoothed. If you have a lot of slabs, you will have to use a lot of smaller rock or pellets to carry the grit and keep the slabs separated while they tumble. So best have 3-4 slabs and different sized rough to make it work.
Lee
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ejs
spending too much on rocks
Member since July 2008
Posts: 478
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Post by ejs on Jul 31, 2008 10:53:44 GMT -5
Thank you for the advice! I am surprised to hear people say that lapis and tigereye don't tumble well. I've had good results tumbling both. Perhaps it is because I am very patient and vigilant with regard to quality control (taking out any with defects, etc.). I'll try to post some photos at some point to make my case.  Using a tile saw is an intriguing idea. I'm not one for powertools myself, but I bet I can find a neighbor who has one. I will try using a chisel and hammer to break some up and then tumble. Perhaps when I am done in several months I'll come back and post about the results. |
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lparker
fully equipped rock polisher
Still doing too much for being retired!
Member since March 2008
Posts: 1,202
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Post by lparker on Jul 31, 2008 12:12:29 GMT -5
Using a tile saw WILL take a week or two or more off your coarse tumble. Using one you can take off all the sharp edges, cracks and holes..any sharp concavities?? Whack it off with the saw. There is a Chinese video out on carving agate, I believe a lot of the work was done on a saw..using it as a grinder. If you're careful you can do some amazing things.. (I don't sell the darn things...just a happy user  |
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Post by deb193redux on Jul 31, 2008 16:03:10 GMT -5
BUT it must be a tile saw with a half-way decent blade. One rated for granite tile. The cheap ones can only cut terra cotta and clay tiles. You would get very frustrated.
Much tigereye does tumble well. But it is a more fiberous silicate than agate or jasper. Like jade (which can be the worst) these fibers can cause uneven surfaces in the tumbler.
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DeanW
has rocks in the head
Member since December 2007
Posts: 721
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Post by DeanW on Aug 1, 2008 1:33:12 GMT -5
Another option is some variation of the rock crusher. Basically a screw- or hydraulic- press or jack mounted in a frame with wedge shaped jaws. Place the rock in the jaws and turn/pump the handle to "split" the rock where you want it. Here again, a notch or groove can help get things lined up where you want.
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fanatic
starting to spend too much on rocks
Member since October 2007
Posts: 233
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Post by fanatic on Aug 1, 2008 5:31:28 GMT -5
Tons of great advice!! I also use 3 lb Lortones. I have a 33A and two 33B's. I have had good results with both the tiger eye and lapis, but the best results came from the 33B's that run a lower RPM. I always use my WF saw to preshape. I've tumbled flat ovals as large as 2 inches across with great results. However, flat surfaces take a very long time to polish in a tumbler so be patient.
The best luck I've had with lapis is if its tumbled with similar hardness materials. I've been mixing it with sodalite and/or rhodonite and gotten good results.
My Home Depot in Gang Mills NY had at least 6 WF saws on the shelf last Saturday when I stopped by. I also happened on a very dusty Hot Dog blade hidden on the back of a shelf. I'd heard they may be discontinuing them at Home Depot and I'm guessing someone set it aside and never came back for it. Sorry someone....its in my stash now!
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