Lapidaryforum.net
Gadgets, Gizmos, and Dohickeys => Cutting, Grinding, Polishing => Topic started by: R.U. Sirius on June 11, 2022, 06:22:53 PM
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I found this considerable chunk of copper ore, with native copper apparent in some areas of the green matrix. I thought slabbing it and then coating to slow down tarnishing would make a decent display piece, so I put it into the 12'' slab saw with a regular continuous rim lapidary blade. I watched it closely, and sure enough within the first two minutes the blade stalled, the oil was smoking, and the rock and the blade were quite hot.
I guess ideally I should be using a blade designed for cuttings meteorites, as this is also mostly metallic...? I don't know anyone with such a blade, though. Would cutting by hand on a water-cooled trim saw make (a little bit) more sense?
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You might get better results using a hand-fed saw. I've never slabbed any copper on a power feed saw, but have done enough by hand to know the copper really drags on the blade. When I hit chunks of copper I use less pressure until the blade chews through it.
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Even metal cutting blades struggle with copper. The best I've done is with a bandsaw but that won't cut the rest of the matrix.
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Are you sure the rock did not come loose and start pinching the blade?
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Are you sure the rock did not come loose and start pinching the blade?
That's a good point. I did check before and after each of the two attempts, and it felt solid in the vise every time.
Now you got me thinking, though - perhaps it did rotate a bit? There are no signs of saw marks on the visible portion of the cut. But there are signs of copper creeping in the direction of the blade rotation, like chewing gum.