jamesp
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Post by jamesp on Feb 2, 2024 22:57:29 GMT -5
It has to be ferro something, gotta be.
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jamesp
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Post by jamesp on Jan 27, 2024 8:46:51 GMT -5
I'm getting old. Thought I posted about Chromium Chloride here, must have forgotten to hit Post. It changes color with Moisture content in dyes and Paints, I wonder what it will do in glass? Cloth: Owl Paint: Why: Coloring agents for glass do tend to be metals Dave. Speaking of cobalt, when the glass blower heats up a load of clear glass say a 50 pound bag it only takes a dab of cobalt to turn it blue. The color travels across the molten mass rapidly which is unique(little to no mixing required). These same metals may also color agate in similar colors. Perhaps obsidian is shades of brown due to sulfur ? Red glass used to be expensive because gold was used to color it, technology has since replaced gold with a much more poisonous(at processing only) cadmium. The EPA was not fond of cadmium in process and forced glass makers to protect workers from it's fumes and rightfully so.
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jamesp
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Post by jamesp on Jan 27, 2024 8:33:41 GMT -5
No worries, Jim, I was just thinking that's a LOT of glass that can be hit or miss with. Expensive experimentation ! Patty Thankfully the glass was obtained at the cost of hauling it off from a warehouse Patty. Sometimes it pays to have a truck and a trailer and some spare time. One man's trash is another's...
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jamesp
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Post by jamesp on Jan 26, 2024 11:53:27 GMT -5
jamesp Good looking glass bricks, even the ones that did not quite come out. Also good to see you active and posting again, your posts with pictures are always a favorite of mine. Stay busy my friend. Henry I agree HankRocks and jamespThanks Dave. We had to add on to the house, that put a wrench in the glass melting. Add Covid... I took many photos of the 2018 melts, the tricks are coming back. Documentation helped. I did use up some key colors, trying to communicate with China to re-stock the used up colors. Communication with China is like doing a Rubik's Cube in total darkness lol. A single crack across the brick is common with pouring from a bowl yielding 2 halves of the brick. Certainly these are 'coefficient of expansion' behaviors. It is a miracle to see 1000 pound boulders of obsidian without fractures throughout. Obsidian must cool very slowly and be in self annealing conditions for it to remain in tact w/out fractures. This is a miracle of nature. Note top sawed section, note pour funnel at top(two notches). Note crack that ran down and across brick yielding two solid half bricks. It takes very little poor conditions to have cracks. Conditions must be perfect. No problem with small or thin pours/melts.
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jamesp
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Post by jamesp on Jan 26, 2024 11:32:41 GMT -5
Can you remelt the failures ? Hope so Patty For tumbling stock it can be re-melted Patty. Re-melt not strong enough for arrowheads. I will mail you out soon, have not forgot you
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jamesp
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Post by jamesp on Jan 26, 2024 11:30:42 GMT -5
Classic case of one glass color(the red in this case)trashing the whole project. There is some out-of-spec red glass in the batch no doubt. Irritating. see fractures when dry, it was the red that propagated all the fractures in the other colors: wet showing colors better, cracks still visible. Just goes to show that conditions have to be favorable for obsidian to not crack, it can be varying temp or chemical issues. It is actually a miracle obsidian can be formed without controlled conditions. Too bad. Those bottom ones are really nice. One single color Tela, the transparent red is a brick killer. One out of like 30 colors is all it takes. This is a shame because I must have 200 pounds of that desirable transparent red glass. It could be that one out of twenty 10 pound plates has defective composition. I will test the other 19 plates to see if they are defective. I did buy a COE 90 red plate from Wissmach(US made) at a high cost, it performs well with the Chinese glass. If buying US glass, a single brick would cost $150 just for the glass...
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jamesp
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Post by jamesp on Jan 26, 2024 11:16:55 GMT -5
"Those are all freakin amazing, but the center left one in the last pic....As far as me getting a kiln, you better not let my wife here you talking like that!" Thanks for compliment. You might be surprised rockbrain, the wives love glass fusing. Used glass kilns cheaper on EBAY hint hint. So it took 10 minutes to hammer break the pieces from plate glass.(i.e. easy pour). The opaque white turns opaque pink. The opaque yellow turns opaque orange. The clear yellow turns opaque yellow. The transparent wine turns transparent blood. The motif is blood-meat-guts-bone, appropriate for spear and arrowhead makers.(I worked way thru college as a butcher) Weigh out 13-14 pounds for 11x6x1.75 inch thick brick. Ready for heat Intriguing surface colors/patterns on top of brick(suggests turbulence mixing). Sawn, 'pattern size scale' small, perfect for arrowheads and cabs. One of my all time favorites. The transparent wine and opaque pink flows very well(reaches low viscosity at melt state).
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jamesp
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Post by jamesp on Jan 24, 2024 15:14:17 GMT -5
Classic case of one glass color(the red in this case)trashing the whole project. There is some out-of-spec red glass in the batch no doubt. Irritating. see fractures when dry, it was the red that propagated all the fractures in the other colors: wet showing colors better, cracks still visible. Just goes to show that conditions have to be favorable for obsidian to not crack, it can be varying temp or chemical issues. It is actually a miracle obsidian can be formed without controlled conditions.
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jamesp
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Post by jamesp on Jan 21, 2024 9:20:00 GMT -5
Great tumbling fodder, oh well. Or cab fodder if anyone wants to give it a go for a cab just say. I'm game to try to cab a piece of "Jimite". Pretty funky looking.
Patty
Patent Pending on the "Jimite"... lol, sure thing, I'll get it to you Patty.
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jamesp
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Post by jamesp on Jan 20, 2024 15:53:27 GMT -5
Will repeat above psych pour with following changes: 1) doubled the size of the pour hole to reduce mixing intensity 2) tripled/quadrupled the size of the glass chips to increase size of each color patch 3) went with brighter colors and avoided browns/blacks 13 pounds
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jamesp
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Post by jamesp on Jan 20, 2024 15:17:49 GMT -5
Melt above. Made a boo boo, forgot to put the 3/16" ceramic felt around the inside of brickmold. Well, glass expands when it solidifies, and it did just that requiring hammerized removal. NO other way to remove. Live/learn. Great tumbling fodder, oh well. Or cab fodder if anyone wants to give it a go for a cab just say. Used a bit too much dark glass. Brick, and the expansion sent fractures. Mold is strong/rigid/unbendable/etc: Hammered results, quite psycho. get back fordite !: Down the inverted volcano pour point: misc chips
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jamesp
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Post by jamesp on Jan 19, 2024 12:53:48 GMT -5
This one should be a wild thang. Even poured it thru a smaller hole to increase mixing. In anneal mode till tonight.
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jamesp
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Post by jamesp on Jan 19, 2024 12:44:55 GMT -5
Will be trying to repeat this 2018 pour. Used a smaller hope in the pour bowl and raised the bowl higher. Somehow the glass poured in thin stream that spiraled as it accumulated and piled in the mold, it also squashed outwardly. The complete dynamics remain a mystery. Note how glass color changes after fusion: Note how colors stayed in order down pontil pipe, but note spiral landing in mold: slabs slabs closer up, more complex up close: tumbled but wet: Trying to coax rockbrain to get a glass kiln...
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jamesp
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Post by jamesp on Jan 19, 2024 12:27:34 GMT -5
Doing a great job my friend! Thanks fossilman.
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jamesp
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Post by jamesp on Jan 19, 2024 12:26:51 GMT -5
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jamesp
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Post by jamesp on Jan 16, 2024 15:41:33 GMT -5
Another tribal pattern did as planned. A thinner arrowhead will reveal the translucent purple glass better than a 5/16" thick slab. backlit
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jamesp
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Post by jamesp on Jan 16, 2024 15:33:32 GMT -5
Knowing nothing about glass fusing, I am curious if the piece with the fractures couldn't be saved? Could you not reheat it slowly to the point where the glass melts enough to fuse together all the fractures? Or can you not get the glass fluid enough for the fractures to properly heal? Maybe the air in the fractures cant "bubble" out so there will still be defects? Inquiring minds what to know! To save energy two bowl/brick melts were performed simultaneously. Peak temp(1475F) dwell time was raised from 3 hours to 4 hours to assure kiln would not struggle to melt 25 pounds total glass. The above brick being brown and black glass could handle the extra heat. However the red glass in the other brick suffered from too much heat and fractured trashing 11 pounds of glass grrr. At raw glass cost of about $15/pound it is good that I acquired this glass very cheap. Has cracks throughout(trash): Herb this glass gets brittle when remelted. It casts one shot excellent. It is not a high quality fusing glass in that way, but it makes very strong glass that rarely fractures upon cooling in thick blocks. Analogy, large and powerful but not quick and nimble. Glass has many trade-offs too. Attempt to take obsidian to fuse/melt temps and most of it will convert to pumice, something in the composition makes it fizzle air bubbles intensely.
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jamesp
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Post by jamesp on Jan 14, 2024 14:20:28 GMT -5
Deep Purple pour brick in kiln today. I'm a sucker for that purple! LOL! You and me both Tela. Such royal purple tickles eyes. Dark purple glass is often used as black glass(you probably know having worked glass). If memory serves a form of cheap iron or perhaps manganese turns glass purple. The sand in NE Florida(manganese rich) makes clear glass that often turns purple when exposed to the elements. The China load came with lots of this near black purple glass. The arrowhead guys should like making some thin points that reveal the purple color depth. I'd prefer to find a giant vein of large amethyst crystals with such color !
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jamesp
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Post by jamesp on Jan 14, 2024 8:32:18 GMT -5
Deep Purple pour brick in kiln today.
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jamesp
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Post by jamesp on Jan 14, 2024 8:25:30 GMT -5
I'll be interested to see what you make with this. I hope this works out well for you. Thank you much rockbrain. This was about the only affordable choice. Shoulda added lavender and purple to complete the natural spectrum. This comes in 7mm-10mm rods, could get cheaper if bought in plates or bricks. Consider the rods offer a whole different dimension in patterns. Certain I will be tooting my horn by posting photos .
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