jamesp
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Post by jamesp on Dec 30, 2016 10:51:11 GMT -5
I saw cobbles and larger rocks into 1" to 1.25" slabs Select piece of Texas pet wood 3.5" X 4.5". Pet wood can be frustrating to break into nice tumble shapes. Saw thinner, 3/4 to 1 inch slabs. With a small hammer strike sawn face at 45 degrees with gently rounded flat face 8 ounce small hammer. Slab laying on a 1 inch thick foam pad. Doing this allows rocks to easily separate from slab with minimum of impact and fractures. Flatter faces. Easier to tumble. Slab at left after being struck full circle. Sawn side being struck Last bit left
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Post by txrockhunter on Dec 30, 2016 11:02:23 GMT -5
1st off, that's some kick butt wood! Thanks for sharing the info. Now I just need to find wood big enough to try that out on!
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jamesp
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Post by jamesp on Dec 30, 2016 11:25:14 GMT -5
1st off, that's some kick butt wood! Thanks for sharing the info. Now I just need to find wood big enough to try that out on! The Georgia coral is found in big chunks. Same trick with it. It is about like glass so it is easy to hammer slabbed or not. Wood, grainy jasper, moss are much more curly or blocky when struck. Depends on replacement with wood. Some of the Texas palm would chip away across the tubes as well as with. Average wood on the Rio is fist sized, easy to do this method. The gravel bars on Jacinto may be feathered down to small sizes. But your Jacinto,s looked tumble ready as found.
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Post by HankRocks on Dec 30, 2016 13:36:46 GMT -5
I have been breaking up most of the end cuts I have. In my case I use a dishpan with sand covered with a couple of dishrags(Not to worry, they are kitchen rejects from the wife, I do have some sense left!) as my breaking zone. Saving the bigger, nicer end cuts for future lapping.
That is a very nice piece of wood in the pictures.
H
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jamesp
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Post by jamesp on Dec 30, 2016 14:30:40 GMT -5
I have been breaking up most of the end cuts I have. In my case I use a dishpan with sand covered with a couple of dishrags(Not to worry, they are kitchen rejects from the wife, I do have some sense left!) as my breaking zone. Saving the bigger, nicer end cuts for future lapping. That is a very nice piece of wood in the pictures. H Dangerous activity for any dish rag, the Ms.'s may have a change of heart and decide she wanted that particular dishrag. The wood was about the size of a half a brick. Are you using the sand as a base to crack the rock on ?
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Post by HankRocks on Dec 30, 2016 15:40:19 GMT -5
Hey, sometimes you just live life on the edge! She has learned that anything that goes to me in the garage has a good chance of being ruined.
Yes the sand below the dishrags absorbs some of the shock and the rocks tends to fracture a bit better, also seems to reduce the shrapnel a bit. I originally put this together for trimming the bad material off of Quartz clusters. Of course I do loose a decent cluster now and then as the break goes right thru the nice points. One of the keys whether it's Quartz, Agate or Petrified wood is to try and locate any natural fractures or weak zones. Sometimes they are just not there.
H
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jamesp
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Post by jamesp on Dec 30, 2016 16:24:15 GMT -5
Hey, sometimes you just live life on the edge! She has learned that anything that goes to me in the garage has a good chance of being ruined. Yes the sand below the dishrags absorbs some of the shock and the rocks tends to fracture a bit better, also seems to reduce the shrapnel a bit. I originally put this together for trimming the bad material off of Quartz clusters. Of course I do loose a decent cluster now and then as the break goes right thru the nice points. One of the keys whether it's Quartz, Agate or Petrified wood is to try and locate any natural fractures or weak zones. Sometimes they are just not there. H "anything that goes to me in the garage" Did you mean "anything she allows you to take to the garage" I like a soft base to break rock on. Fractures can originate from the bottom of the rock when sitting on a steel plate.
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spiritstone
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Post by spiritstone on Dec 31, 2016 10:05:28 GMT -5
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jamesp
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Post by jamesp on Dec 31, 2016 10:27:52 GMT -5
OMG spirit. Quick tumbles no doubt. Could send unwanted fractures... Not sure the reason, but there used to be a lot of small rock crushers. Perhaps for crushing ore. Many much smaller than this one:
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spiritstone
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Post by spiritstone on Dec 31, 2016 11:00:58 GMT -5
OMG spirit. Quick tumbles no doubt. Could send unwanted fractures... Not sure the reason, but there used to be a lot of small rock crushers. Perhaps for crushing ore. Many much smaller than this one: It would be fun to find out. I'm just guessing fracturing might go either way. A lot of stress on them to pop leading to a clean result maybe? Ore or Coal? The belt driven vintage rock crusher reminded me of the old balers rusting away on the farm I used to play on. Cool pic!
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jamesp
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Post by jamesp on Dec 31, 2016 11:32:37 GMT -5
Georgia produces mega tons of granite gravel spiritstone. They use spring loaded parallel plate crushers. Similar concept as the one you posted. I think the plates are 6 inches thick, 4' X 4', oscillating and in long rows so rocks enter at each step and are reduced a bit each step till the plates are 3/4 apart for pea gravel. Different sized gravels vented out midstream. They are a bit seismic machines, ground shakers. Be careful, that old farm machinery may date you. It would take a long time to rust this beasts away.
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Fossilman
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Post by Fossilman on Dec 31, 2016 15:00:47 GMT -5
Yuppers,I use my 14" to break down some of the larger tumblers (rocks) I want to use....
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jamesp
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Post by jamesp on Dec 31, 2016 15:19:31 GMT -5
Yuppers,I use my 14" to break down some of the larger tumblers (rocks) I want to use.... Makes life and tumbles way better. Hate to sink a hammer into a fine 4+ inch cobble of fine stone when it is whole.
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Post by toiv0 on Dec 31, 2016 16:24:37 GMT -5
OMG spirit. Quick tumbles no doubt. Could send unwanted fractures... Not sure the reason, but there used to be a lot of small rock crushers. Perhaps for crushing ore. Many much smaller than this one: Small rock crushers used to used a lot in labs. Could handle softball size rocks and adjust to finished size. I don't think a small jaw crusher could be made with a concentric shaft some hard plate and hard surface rod.
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Deleted
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Post by Deleted on Dec 31, 2016 18:05:43 GMT -5
OMG spirit. Quick tumbles no doubt. Could send unwanted fractures... Not sure the reason, but there used to be a lot of small rock crushers. Perhaps for crushing ore. Many much smaller than this one: Small rock crushers used to used a lot in labs. Could handle softball size rocks and adjust to finished size. I don't think a small jaw crusher could be made with a concentric shaft some hard plate and hard surface rod. Needs a cam of some sort. One I looked at used a round of steel sliced 3/4" think. How drilling off center to mount on a shaft. Then welded to said shaft.
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jamesp
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Post by jamesp on Jan 1, 2017 2:15:39 GMT -5
Keep in mind that the target to fine tumbles is minimal fracturing. Minimal impact on the edge of a flat mother rock allows a vent for the separated rock to release from the mother rock. Rock crushers don't think that way; they are designed to crush rocks. Striking a flat rock along the edge is Native man's method to make a spearpoint. Spearpoints can not have fractures and function. A flat striking surface allows control. A rough striking surface reduces control. Typical core from Native man's handy work Zero fracture chips for tumbling struck from thick sawn slabs. Intentionally struck thin as possible in this case. Thicker pieces easier. This is coral and easy to work with. Can saw 3 inch thick slabs and hammer tumbles away from it. Almost like obsidian.
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jamesp
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Post by jamesp on Jan 1, 2017 2:31:36 GMT -5
Another example. Dense grainy stone. Worst case, does not chip conchoidal whatsoever. Darn near like granite in terms of texture. No idea what this rock is. Collected at Rio, 3" X 4" X 4". Left rock sawn too thick at 1.5". Should have sawn at 1" thick like right slab. Too dense and grainy for 1.5". 1.5" slab had rejects, could not send fracture completely thru. 1" slab had about zero loss. Results ready for tumbler. Not the best but not bad. Note grainy and rough surface. Stubborn rock, required hard and fast blows. Some concave areas. About 30% of the pieces were rejected due to divots and concave areas. But these keepers will tumble quite well.
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jamesp
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Post by jamesp on Jan 1, 2017 2:57:21 GMT -5
Similar to a core, from 1" thick slab. Gnarly ass pet wood. Same scale, above core reduced, too small too strike further
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jamesp
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Post by jamesp on Jan 1, 2017 3:13:09 GMT -5
Extreme case. Not my doings. I guess these chips would be more like 3-4" long thin razor blades(for shaving?) Certainly too thin for tumbling. Note flat end for accurate percussion. Fine material, fractures travel full depth. Control to the max
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Post by Garage Rocker on Jan 1, 2017 17:27:30 GMT -5
Looks like you worked up a bunch of fine tumble material. The tile saw takes a bit longer, I think I'll try your hammer trick next time out.
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