timloco
has rocks in the head
Member since April 2012
Posts: 545
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Post by timloco on Feb 4, 2014 9:56:32 GMT -5
So, I've been playing with labradorite. Awesome material. Frustrating material. It tends to fall apart along unseen fractures and yet something that looks like a heinous fracture is fine. I've seen mention of "stabilizing" it. What does that entail? Any other suggestions?
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Don
Cave Dweller
He wants you too, Malachi.
Member since December 2009
Posts: 2,616
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Post by Don on Feb 4, 2014 10:23:49 GMT -5
Back it a thin slice of something else to keep it from falling apart.
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timloco
has rocks in the head
Member since April 2012
Posts: 545
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Post by timloco on Feb 4, 2014 10:29:28 GMT -5
like a doublet? I have not tried that yet... Any kind of material in particular?
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Don
Cave Dweller
He wants you too, Malachi.
Member since December 2009
Posts: 2,616
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Post by Don on Feb 4, 2014 10:36:25 GMT -5
Yes, like a doublet. Basinite or black obsidian would be nice. the dark color would contrast with the labradorite and bring out the flash.
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SirRoxalot
freely admits to licking rocks
Member since October 2003
Posts: 790
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Post by SirRoxalot on Feb 4, 2014 10:40:36 GMT -5
There are various methods of fracture sealing. Generally messy and expensive-ish, or time-consuming at the least.
Combine a tube of epoxy 330 and a pint of acetone, mix well in a mason jar, add rock, seal and soak for a couple of weeks, giving it a shake or two daily. Let dry for two weeks. I have a batch of material treated this way but I've yet to cut it so I cannot personally attest to the effectiveness quite yet. Main thing is it has to be 330.
Then there's Opticon, I can vouch for its effectiveness, helps if you have a little toaster oven or other source of heat, and a lot of rocks to do. Follow the instructions on the can, it's basically painting the stuff on and heating it, then adding the second part, can't remember the details. Gotta do it outdoors.
Being a feldspar, the stuff has great cleavage. If you don't want to stabilize, simply don't cut pieces with cleavage lines, split them up, or they'll fail.
And remember, low or no dome, cut 'em flat to show the flash.
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timloco
has rocks in the head
Member since April 2012
Posts: 545
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Post by timloco on Feb 4, 2014 10:56:52 GMT -5
Low or no dome? Huh. I cut one with a pretty high dome and it turned out ok (apart from the scratches I missed lol):
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timloco
has rocks in the head
Member since April 2012
Posts: 545
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Post by timloco on Feb 4, 2014 11:15:58 GMT -5
I went to re-photograph this one and, alas... So, you see my frustrations ;-)
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Post by rockjunquie on Feb 4, 2014 14:16:32 GMT -5
Bummer I hate when that happens.
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Post by pghram on Feb 4, 2014 16:41:32 GMT -5
I can't help with the stablization question. I've only played w/ some tumbling quality. Looks like you have nice slabs so I hope you figure it out.
Rich
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juzwuz
has rocks in the head
Member since April 2010
Posts: 526
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Post by juzwuz on Feb 8, 2014 15:08:18 GMT -5
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timloco
has rocks in the head
Member since April 2012
Posts: 545
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Post by timloco on Feb 8, 2014 20:46:00 GMT -5
cheers thanks juzwuz that's a great page... Kinda wish I would have seen his cutting page before I slabbed that last one though oh well :-)
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Post by radio on Feb 8, 2014 21:04:51 GMT -5
If you don't want to bother stabilizing easily fractured material, before cutting, you can back it with plastic steel like a lot of thin Turquoise is done. I prefer Devcon two part plastic steel epoxy. www.tapplastics.com/product/repair_products/adhesives_glues_sealants/plastic_steel/279I have used J-B Weld and a couple of others, but the Devcon is the best I have found. Also available in convenient 1 pound containers and 5 gallon buckets It can be filed, sanded or cut on your diamond wheels or flat lap. If you form a dam around the base of the stone with tape, fill it with the steel and then place the still soft steel on a smooth plastic lid of some kind, you will get a very smooth, semi gloss bottom. Just try to press it down evenly and to the correct thickness so you don't have to grind it flat after it sets up
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carleton
spending too much on rocks
Member since April 2012
Posts: 277
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Post by carleton on Apr 16, 2014 11:27:03 GMT -5
Hello, Sorry I missed this post. I know this is an old post now, but in case anyone digs it up I thought I would reply. Commenting directly to the cleave issues, there are a few things you can do or look for in the rough, and especially the slabs to try and avoid disappointing breaks. When in rough form, if you ever observe a yellowish/brown coloring on the skin, or deeper, you can normally assume that area will crumble. Even if it does not, that discolored area will typically give your finished cabs very visible natural cleaves and plays havoc on flash... in the end it normally makes for un attractive finished pieces even when it does not fall apart. Its normally safe to cut those sections off. I should note, that natural cleaves do not always or even normally have that "yellowed" appearance, its more un common if anything, yet the yellowing is always a red flag. When in slab form, you get a very good look and idea of what will happen. The same rule from rough applies, but now that it is in slab form, you will really get a sense of what I previously spoke of, because that yellowed section will display perfectly parallel cleaves quite visible. I always cut around that. Don't rush to get your slab wet, when dry (but clean) "cracks" (not so much natural cleaves) will be 10x's more visible when dry. Cracks can simply be "cosmetic" but will be more of an eyesore in your finished piece than natural cleaves (for the most part, not including the "yellowish" ones) because they will normally slightly alter the flash. Yet when the crack is cosmetic and does NOT effect the flash... the flash of the finished stone will make the cracks invisible, yet when the flash is inert, the material will still show that crack quite well and you will get that love hate feeling for your cab as you move it around and watch the flash hide it, then not, then hide it... etc. Back to those natural cleaves. firstly you can always just give it a bit of pressure to see if it snaps, if it is an obvious cleave line. That's my first test, second test is one of the best I have come up with. Submerge the slab in water and gently flex the slab (the one you have already tried the snap test to). If you see little bubble form along the cleave, and especially if you see them appear then disappear with the flexing motion... you can be pretty certain there is a chance all the trauma from working the stone will eventually cause the piece to separate. Visually, you can also get a limited idea of how concerning the cleaves are. I have found more times than not, that anytime you see a nice natural cleave that appears to have a dark or black looking "vein" appearance to it... its going to come apart. Some Labradorite has nice black veins in it... but the ones I am referring to are linier and 100% straight. Some times the best way to see this is to get the slab wet and look at the cleave lines on an angle, and even back lit at times. These types of cleaves generally have a blackish (micca in appearance) inner wall, as in, if the cleave breaks and you observe the inside, (or side) you will see that characteristic. So that was my attempt to shorten it up Hope it helps. Carleton
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Post by 150FromFundy on Apr 16, 2014 15:58:53 GMT -5
As for the dome ... low dome, or bevelled flat. If you look at carelton's "killer" cab above, it is essentially a bevelled flat.
Once you find the plane of maximum flash, you want to maximize that plane in either a low dome, or a flat. A high dome may have some flash, but chances are you will loose the flash as you dome towards the edges.
Darryl.
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