|
Post by toiv0 on Dec 1, 2016 6:40:53 GMT -5
Going to get my windshield replaced tomorrow. Does anyone use tempered glass for filler material in their tumbles. I did a search and couldn't find any posts. The glass shop said they had a few side glass panels they could break up for me.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,179
|
Post by jamesp on Dec 1, 2016 7:31:44 GMT -5
Going to get my windshield replaced tomorrow. Does anyone use tempered glass for filler material in their tumbles. I did a search and couldn't find any posts. The glass shop said they had a few side glass panels they could break up for me. I have used it Billy. I find the pieces were too small. It depends on the thickness of the glass. Window glass for a house is too thin. Some car glass may approach pea size. 1/2" and 5/8" and 3/4" table glass is way to big when crushed up. Broken booze bottles are crushed at recyclers to a perfect 3/8"(pea size). Would guess that 1/4" tempered would do about perfect. Just keep in mind when you use glass for media you may have a lot of gas in a rotary. And if you use glass in the coarse grind you will get a lot of slurry. some tempered glass is real soft. Some not. No problem having gas in a vibe since they are rarely sealed. Do yourself a favor and use quartz pea gravel instead. Good quartz, like from an aquarium shop.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Dec 1, 2016 17:39:47 GMT -5
Windshields aren't tempered. They are laminated glass. That with a layer of plastic between the glass layers.
I tried the cubes. Made too much gas for my liking.
|
|
|
Post by toiv0 on Dec 1, 2016 17:49:06 GMT -5
Windshields aren't tempered. They are laminated glass. That with a layer of plastic between the glass layers. I tried the cubes. Made too much gas for my liking. Beans have the same affect on me, but I still eat them. I will probably use them in a vibratory. Why do they produce gas? Is it in the glass and released when broken down?
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,179
|
Post by jamesp on Dec 1, 2016 17:53:14 GMT -5
Glass has bubbles. Apparently the bubbles have compressed gas that releases when breeched by grinding.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Dec 1, 2016 19:34:27 GMT -5
Glass has bubbles. Apparently the bubbles have compressed gas that releases when breeched by grinding. It seems that atmospheric gases are dissolved in glass during production. The cutting and grinding releases them. Googling gas dissolved in glass produced a lot of good science. Weird.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,179
|
Post by jamesp on Dec 2, 2016 10:12:38 GMT -5
Glass has bubbles. Apparently the bubbles have compressed gas that releases when breeched by grinding. It seems that atmospheric gases are dissolved in glass during production. The cutting and grinding releases them. Googling gas dissolved in glass produced a lot of good science. Weird. Your cost goes way up on a camera with 'fine glass'. Bubbles are optical glass killers. Glass totally complicated. Glass is believed to be the strongest material on earth IF it has no scratches on it's surface in a non-impact bending test. Rubbing a dirty finger across the surface reduces it's strength in such a bending test exponentially. Due to scratching. Microscopic scratches that propagates fractures therefore weakening it. Think glass cutter. Glass and obsidian (same thing) not conducive to tumbling due to impact associated w/tumbling process. And lots of different kinds of glass. I think borosilicate is lens glass; it might be one of the softest glasses.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Dec 2, 2016 10:18:24 GMT -5
Study camera lenses and you will find that the high end ones use minerals to provide specific properties. An entirely different animal.
Fluorite glass is one of them.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,179
|
Post by jamesp on Dec 2, 2016 11:53:26 GMT -5
3000 psi oxygen cylinders. I think the formula is p1 X v1 = p2 X v2 at room temp. So if cylinder is 2 cubic feet, 3000psi X 2 ft cubed = 14.7 X volume cubed 6000 = 15 x X X = 400 cubic feet of oxygen at room temp. at room pressure
So 2 cubic feet of air @ 3000 psi becomes 400 cubic feet of air at room pressure. If calculation was done correctly. so the gas pressure build up in a tumbler.
Yes, minerals change the 'index of refraction' in glass. Like shooting a fish underwater from above.
|
|
Deleted
Deleted Member
Member since January 1970
Posts: 0
|
Post by Deleted on Dec 2, 2016 13:56:27 GMT -5
You calculation correct.
Your calculation seems tortuous though.
Pressure ÷ 14.7 • volume = volume at normal pressures. Maybe that's what you said? **
However, at 1500° (or whatever) of a glass furnace not much air is present. Its expanded and very thin at such temps. Still, what is present is apparently highly soluble in the glass.
Ain't science grand?
**SCUBA class teaches this day one. Very important in SCUBA.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,179
|
Post by jamesp on Dec 2, 2016 19:58:34 GMT -5
Yes, scuba guys need to know Boyle's gas law. Life or death.
Heating to lower viscosity makes perfect sense.
Science nurds rule
|
|
|
Post by toiv0 on Dec 2, 2016 20:08:29 GMT -5
Pretty cool stuff guys, going to self medicate my brain now.
|
|
dottyt
spending too much on rocks
Member since July 2016
Posts: 305
|
Post by dottyt on Dec 3, 2016 2:46:32 GMT -5
The lady who does a lot of tumbling at my club brought in some tumbled car windshield glass when she gave a lecture. She tumbled it just to see how it would turn out when a friend's car was broken in to. She tumbled it to different degrees of polish and it looked pretty cool when put into glass bottles. The pieces retained their squarish shape, but were somewhat rounded. She always releases the gas from her barrels every 2-3 days. She didn't report any problems with it. She said it took much less time than rocks, but I forget how long she tumbled it for. She said it was ~Mohs 5.5, seems like it would be too soft to use as a filler, but it made a nice decorative item.
|
|
mishabear
off to a rocking start
Member since August 2018
Posts: 2
|
Post by mishabear on Aug 6, 2018 15:28:19 GMT -5
Getting back to the original question, I am totally new to this. I am doing mosaics and am seeking to tumble actual tempered glass (from a broken slider door) to liken it to sea glass if possible. I like the idea of tiny pieces to use as outlines and have gotten a cheap tumbler from Harbor Freight to start my experimentation.
Reading this thread, I have some questions.
1> What is the issue with gas? 2> Should I pre-heat the glass prior to tumbling to soften it some? If so, suggestions on how? Would 500 degrees in a household oven do enough? Or do I need to go the kiln route? 3> Using a mixture of sand, regular pea gravel, course grit, salt, and water. Suggestions for changes/ratios?
Thanks in advance all for your brain morsels!
|
|
Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,426
|
Post by Wooferhound on Aug 6, 2018 18:23:51 GMT -5
1> What is the issue with gas? 2> Should I pre-heat the glass prior to tumbling to soften it some? If so, suggestions on how? Would 500 degrees in a household oven do enough? Or do I need to go the kiln route? 3> Using a mixture of sand, regular pea gravel, course grit, salt, and water. Suggestions for changes/ratios? I thought the gas issue was discussed very well in this thread, complete with informative scientific links.
Glass is already plenty soft, in most cases, softer than rocks, no need to soften them up anymore.
Use Grit, Gravel and Water, Sand and salt won't help any
Are you just wanting to frost the surface of the glass or, are you wanting to round it off some ?
|
|
mishabear
off to a rocking start
Member since August 2018
Posts: 2
|
Post by mishabear on Aug 6, 2018 19:02:43 GMT -5
Like I said, I am new to all this. Trying to learn what I can from more experienced minds!
1> I guess I mean why is gas an issue? I see a lot about it ("I tried the cubes. Made too much gas for my liking.") but no indication why gas is a problem. 2> I didn't know if the temper of the glass was an issue compared to non-tempered bottle glass, etc. thus my "softening" question. 3> I am okay with just the frosting, not rounding although rounding would be welcome to a degree.
I will try gravel, grit, and water.
Thanks!
|
|
Wooferhound
Cave Dweller
Lortone QT66 and 3A
Member since December 2016
Posts: 1,426
|
Post by Wooferhound on Aug 6, 2018 20:47:44 GMT -5
When tumbling in a Rotary Tumbler, the barrels are sealed against leakage. If pressure builds up inside the barrel it can pop off the endcap dumping the contents and making a big mess. When tumbling glass you should break the seal and equalize the air pressure every couple of days or if you see the barrel bulging. I have been tumbling Pyrex from theatrical lighting fixtures and that stuff can be quite hard, but is still easy to frost-up and round the edges. Are you talking about the tempered glass that breaks into a zillian little diamond shaped pieces ? Different grits will give you different results, larger grits like 46 or 80 will give you very fast results and do the most rounding. Medium grits like 120 or 220 will be great at frosting but milder at rounding the edges. Fine grit like 500 or 600 will frost the glass shallowly and leave a sheen on the glass. Smaller grits greater than 1000 are generally used to make the surface shine.
|
|