jamesp
Cave Dweller
Member since October 2012
Posts: 36,562
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Post by jamesp on Oct 5, 2013 9:14:31 GMT -5
I heat a lot of petrified coral to bring the color out. The outer layer is often brilliantly colored. Depending on the material. So if you heated a partially finished cab you could grind away a color layer. This coral was about the size of a golf ball when it was cooked. Then it was broken to what you see. The hot red was the area exposed to the heat before it was broken to pieces. So if you had a preform of exact finished shape and heated it, material could be removed so that the cab was perfectly bordered in the exposed color. As could be a fade to the top of the dome... Not just coral, a lot of materials have a hot color coating that could be ground back to another interior color. For effect. (Disregard the black and white layer. That was the original coating at formation.) These chips were cooked. They represent numerous pieces of coral. But they were heated as chips so that the ones w/a bright coating will change to the internal color as the tumble grinds sharp edges and high places. Leaving a cool color fade. Only about 1/4 of them have that outer color layer. Often the brighter materials. So if the slab was heated, you would have a color change at the surface and then cut a preform and have a fade on the dome alone.
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Tommy
Administrator
Member since January 2013
Posts: 12,905
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Post by Tommy on Oct 5, 2013 11:15:41 GMT -5
Outstanding idea James ... and your organizational skills are amazing :-)
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,562
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Post by jamesp on Oct 5, 2013 11:17:06 GMT -5
Lots of space and a nursery full of black pots sure helps!
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Post by Pat on Oct 5, 2013 13:31:25 GMT -5
Beautiful! For effect, I would also leave on the black and white edge to the color.
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kaldorlon
spending too much on rocks
Member since October 2013
Posts: 413
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Post by kaldorlon on Oct 5, 2013 15:54:51 GMT -5
Very nice job and good idea!
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grizman
freely admits to licking rocks
Member since July 2011
Posts: 878
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Post by grizman on Oct 5, 2013 20:24:41 GMT -5
That sounds like a great idea for both cabbing and maybe even some tumbling? Now we are waiting for someone to prove your idea correct! Of course, then we want to see them...
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,562
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Post by jamesp on Oct 5, 2013 20:28:27 GMT -5
Point made. Lets see what tumbling some of these does.
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Post by Pat on Oct 5, 2013 22:48:49 GMT -5
jamesp your photo of the buckets would make a neat picture to hang in your office/business.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,562
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Post by jamesp on Oct 5, 2013 23:35:55 GMT -5
I could do calendars if my wife would let me hire girls to model them. I would be worried about the focus going to the girls and my wife killing me. Serious compliment and i thank you.
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Fossilman
Cave Dweller
Member since January 2009
Posts: 20,711
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Post by Fossilman on Oct 6, 2013 14:53:34 GMT -5
Great idea James!
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Post by pghram on Oct 6, 2013 15:01:18 GMT -5
That is an intriguing idea. I have seen some batcave (I have never cabbed this material) that has that effect & it 's extraordinary. You should definately give it a try.
Rich
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,562
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Post by jamesp on Oct 6, 2013 15:41:56 GMT -5
I looked for info on heat treating bat cave and came up short. i see it is found in Prineville OR and is fine material. Many jsapers can be enhanced w/heat. I ill keep my eyes out for that one Rich.
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Post by pghram on Oct 7, 2013 9:10:53 GMT -5
James,
I don't know if it is heat treated, I was just talking about the visual effect of the gradation of color that cooking & then gringing of the coral would/might create. Sorry, I didn't mean to cause any confusion.
Rich
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,562
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Post by jamesp on Oct 7, 2013 11:18:44 GMT -5
I see. It is often difficult to saw a rock to get a laminated color effect. I have seen it done. This would be a lazy way of doing it..
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jgflutes
off to a rocking start
Member since January 2014
Posts: 4
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Post by jgflutes on Jan 17, 2014 20:47:57 GMT -5
You can use an old electric turkey roaster to heat treat material in. They can be purchased at Wal mart for about $45 new or you can usually find them in a flea market for about $30. You can get the material up to about 500 degrees with this method. I put a layer of sand on the bottom and then a layer of stones on top. Cover material with sand and then another layer of stones until the roaster is full. I usually have about 4 inches of sand on top. I also cover the top with fiberglass insulation. The glassier material should be toward the top and the lower quality on bottom. The temperature in the oven will be higher toward the top.Try to fill with material that is similar. Some material will change at 250 degrees and other at 500 degrees. Just try some and keep records so you know what works best. Bring temperature up at 50 degrees per hour ( just go by the dial on the oven temperature control) until you have reached the temperature you want and then leave it there about 2 to 3 hours. You can install a regular temperature gage in the side but it is not neccessary. I then turn off the oven and let it sit about 24 hours. Color changes will depend on what minerals are in the material. Do not try to heat treat any black or dark grey material because it has oil residue in it and it will blow up or crack. The glassier the material the less heat it takes. I am also a flint knapper and have been heat treating rocks for about 30 years. Chalcedony & paint rock agate takes about 500 degrees to get the best color change. I have had clear or milky chalcedony turn a beautiful pink when heat treated and at the same time it becomes like glass. Heat treating is not an exact since so experiment with small batches to determine what temperature you need to use. On some of the flint knapping forums you can get info on heat treating charts that tell the temperature to use for different material. You cane contact me at jgflutes@aol.com for any questions.
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jamesp
Cave Dweller
Member since October 2012
Posts: 36,562
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Post by jamesp on Jan 17, 2014 21:13:54 GMT -5
I use a n industrial furnace jg. Got it dialed in for coral. That is all i cook. No interest in other stuff except coastal plain chert.
I have a great time fooling w/it. Don't even knap. Just tumble.
I appreciate the tips and welcome you to the forum.
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