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Post by Donnie's Rocky Treasures on May 24, 2010 19:40:56 GMT -5
Is there a best way to look at a rock or cut into it in order to get the full potential from it. I am looking at these rocks from Tony & can see some really neat stuff there. But how do I determine the best way to cut it? Some I can see I will have no choice others it's a toss up as to whether I cut it long way or across. Any hints or suggestions please? Donnie
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Post by stardiamond on May 24, 2010 20:09:20 GMT -5
Here's how I do it. If there is enough material and there is an exposed face, I cut a thin slice including the skin, at 90 degrees from the exposed face. This will give you a clue on which way to cut. If it picture jasper, it will also let you know how deep the picture is the exposed face. If after exposing two faces and nothing appears that you like expose another face at 90 degrees to the two previous faces. Here's a really nice piece of blue biggs that I have gnawed some slabs from. I will keep taking slabs from the preferred face until I know the pattern will disappear and then have to decide when to stop and leave a reasonable size on the 90 degree face.
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Sabre52
Cave Dweller
Me and my gal, Rosie
Member since August 2005
Posts: 20,466
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Post by Sabre52 on May 24, 2010 20:16:31 GMT -5
Hey Donnie: Mostly determining the right way to cut a stone takes a lot of study. Except in the case of some nodules which have full skins you can usually wet a rock in full sun and learn a lot about what patterns it may contain to give you some idea of what you're looking for and the direction you want to make your cuts. The next thing I do is check for visible fractures. If there are any, you want to cut perpendicular to them rather than parallel to minimize the chances of the rock blowing apart and destroying your blade. How the rock sets in the vice may limit your direction of cut too. Sometimes, it's necessary to make a few extra cuts to properly seat and orient the rock in your vise. Next it becomes sort of a personal choice. Some folks like to slab for maximum output ( largest number of slices). Myself, I prefer to sacrifice some rock to try to obtain the most desirable pattern, sometimes just searching for a particular single cut for a particular cab. If your cutting expensive stuff for resale or a maximum number of cabs, you may think differently. Folks who cut for polished specimens may choose differently too. Remember you always want to orient the workpiece is such a way that the stone approaches the blade perpendicular to the blade to avoid having the blade slide along the rock and start a cut with the blade canted to one side or the other. This will quickly dish your blade and maybe ruin it very quickly. Re: Your long way vs crossways question. If the rock is solid and homogeneous, choose whatever direction looks best for your uses. If there is any indication of grain that might show cleavage planes or fractures, cut across the grain to avoid breakage along those weaker planes. Patternwise it's just good to know your materials. Some are obvious, picture jaspers for instance. Lots of plume agates need a specific orientation to get a good display of plumes. Nodular types usually have to be cut open like biscuits because lots of plume is parallel to the top and bottom of the nodules, Vein type plumes like Graveyard Point are best cut perpendicular to the top and bottom as plume runs bottom to top.. You'll learn after you experiment a bit with the materials you find. The most important thing is to know what you're looking for from a particular type of stone...Mel
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Post by stonesthatrock on May 24, 2010 20:37:47 GMT -5
ok, i think mel has said it all and thats pretty much the samething we do. Wonderful answer mel, very helpful
mary ann
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Post by johnjsgems on May 24, 2010 21:32:24 GMT -5
As usual, once Mel answers there isn't a need to add more. When all that is second nature you will be there. If it wasn't clear, after you have the rock clamped properly gently slide the carriage until rock just touches the blade. If it deflects at all don't cut there. When I'm slabbing I'll turn the handle a 1/4 turn at a time until I get a good contact even if it means that slab is a little too thick or too thin. Better a bad slab than a bad blade.
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Post by frane on May 25, 2010 8:06:00 GMT -5
Great answers and great help from all! Fran
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