jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 2, 2018 6:36:04 GMT -5
I had strange results using the torch. One big problem was the cool down. cooling cracks galore The microwave kiln offers a fast cool down so it says. Similar to heat treating rocks, you about have to cool them as slow as you heat them. Heating glass in an electric kiln is similar, a half a day to heat up and cool down minimum. This device cuts that time way down. Perfect for tumbles. Electric kiln does much larger projects though. Just filled the oxy/acet. tanks. not even full size $148... If serious with kiln melting glass it would be wood fired, cheapest fuel at this zip code. It takes about 4 to 6 hours for an average heat schedule for 1/8 inch thick sheet, in the glass kiln, and about 8 hours for the annealing cool down to room temperature. The thicker the glass the longer the time you add. I would think a Microwave kiln would cool off way to fast to keep the glass from cracking, which would be from 900 degrees to room temperature.
As far as oxy and acetylene, have you considered propane and an Oxygen Concentrator?
I was looking at doing the volume of 4 marbles, hopefully 1" marbles in the microwave kiln. I will report back on that attempt toolnut. I hear where you are coming from regarding heat up and cool down times with glass. Just heat treating agate and chert is similar in that it takes 2 to 4 days to ramp up and ramp down at only a 600F heat treatment. With dry rock, wet rock longer. The concept of a large back woods masonry kiln is simple, use a longer than needed heat up and cool down. It is passive. Fire multiple projects in a large fire box that has a large thermal mass surrounding it. And simply ramp up and ramp down over a period of a week or longer. It requires filling the fire box with wood one, two three times a day. 1000 pounds of fire wood comes cheap in these parts and only takes about 2 hours to prepare. Basically a 16 foot oak log say 20 inches in diameter, a pick up truck load. May take 2 loads. Such a kiln should be able to fire 100 pounds of glass at a time in less than 1 inch thickness projects. Talking a kiln with 2 foot thick rock walls lined with fire brick, a beast. Field rock and fire brick. 2000 pounds of firewood has a massive supply of energy. Comparative cost in acetylene and propane substantial. It is not unusual to burn 20 to 30 such pick up truck loads of firewood in one Georgia winter heating the house. Fire wood is a way of life on the farm and a couple of acres of well forested land can supply most of a life time's worth of fire wood. Best build the kiln on or near the fire wood lot. I believe the potters of old fueled themselves with moonshine. They had a reputation for such. Sitting in a shed heated by the kiln. Not pretty
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 2, 2018 7:29:49 GMT -5
Here in the SE US pottery kilns were the norm for many years. Including glazing operations. With all the fine clay availability pottery goes way back. Probably requires intimate knowledge of your kiln. They are bulky. Not to big of a deal to build on a farm where space is available. Certainly albatrosses. The fuel is about free. Not sure how these kilns relate to glass kiln performance/requirments. Glass kilns are pretty precise today and are a real necessity if doing a lot of glass firing. Glass has firing schedules that ramp up heat in programmed increments, to keep it from cracking, and different glass and different thickness are a part of the schedule. A glass kiln saves all your own schedules and has a library of pre programmed schdules that you just pick and use in "Express" mode. It also operates the kiln on cool down, to keep the glass from cracking. The bigger the chunk of glass, the slower it needs to be cooled to room temperature. Have been running the kiln each day this week, making bent panels for an antique lamp. Have 4 more to make, since its a 8 panel lamp.
Soon as I am done with this project, will try a batch of melted color glass to see how it turns out as a cheap media source for tumbling. Any Ideas on size of ideal chunks or pieces that one would use for tumbling or breaking up, would be appreciated. The good thing is that making the chunks, you can pick your size and shape, unlike a rock.
A pot melt making a 3/4 to 1 inch slab would be perfect. Then break into tumbles with hammer. Or Yesterday a trip to a freight salvage store had glass work labeled Murano for 2 to 3 dollars per pound. Must have been 500 pounds worth. I doubt a kiln will be needed with the availability of art glass May be fake, may not. No matter. It will be hammered into tumbles. Purchased these for $20, 12 pounds of glass. Min. 1/2 inch thick. $100 dollars would keep the tumbler busy for a long time and provide many colors. Maybe someone knows if it is authentic Murano ? MsAli ?
|
|
|
Post by Garage Rocker on Jan 2, 2018 7:43:50 GMT -5
Nice score, jamesp. I'm half way through a glass tumble, but have it on hiatus until the temp gets out of the teens and single digits around here.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 2, 2018 8:32:20 GMT -5
Talk to me about your selection of glass and how you will tumble it in the vibe Garage Rocker. Ceramics ? Percent media ? Your secrets Like is the glass a mixed sort or all from one source ? 16F this morning with no wind chill. May have some frozen rotary action over in the greenhouse... The Vibrasonic gets hot with the motor mounted under the hopper, hard to freeze it.
|
|
|
Post by MsAli on Jan 2, 2018 8:37:31 GMT -5
Glass kilns are pretty precise today and are a real necessity if doing a lot of glass firing. Glass has firing schedules that ramp up heat in programmed increments, to keep it from cracking, and different glass and different thickness are a part of the schedule. A glass kiln saves all your own schedules and has a library of pre programmed schdules that you just pick and use in "Express" mode. It also operates the kiln on cool down, to keep the glass from cracking. The bigger the chunk of glass, the slower it needs to be cooled to room temperature. Have been running the kiln each day this week, making bent panels for an antique lamp. Have 4 more to make, since its a 8 panel lamp.
Soon as I am done with this project, will try a batch of melted color glass to see how it turns out as a cheap media source for tumbling. Any Ideas on size of ideal chunks or pieces that one would use for tumbling or breaking up, would be appreciated. The good thing is that making the chunks, you can pick your size and shape, unlike a rock.
A pot melt making a 3/4 to 1 inch slab would be perfect. Then break into tumbles with hammer. Or Yesterday a trip to a freight salvage store had glass work labeled Murano for 2 to 3 dollars per pound. Must have been 500 pounds worth. I doubt a kiln will be needed with the availability of art glass May be fake, may not. No matter. It will be hammered into tumbles. Purchased these for $20, 12 pounds of glass. Min. 1/2 inch thick. $100 dollars would keep the tumbler busy for a long time and provide many colors. Maybe someone knows if it is authentic Murano ? MsAli ? Need to see a better picture of the sticker and the bottom of the pieces. I am 99% positive that yes they are Murano pieces. The blue and clear would be a piece from the 70's. The green I need to see more of
|
|
|
Post by Garage Rocker on Jan 2, 2018 8:40:39 GMT -5
I've already completed about half of what I started, just waiting until the rest is done before taking pics. It's a mix of obsidian, slag glass and that color change neodymium glass from Billy. What I've finished so far is Lot O'riffic. About 50% mixed size ceramics and mix of glass types. The usual steps, plus AO 1,000. No problemo.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 2, 2018 8:59:13 GMT -5
|
|
|
Post by MsAli on Jan 2, 2018 9:02:05 GMT -5
The blue and white one is a fake. Although pretty. The green and blue is the one I'm more curious about. Does it have a sticker?
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 2, 2018 9:02:54 GMT -5
A pot melt making a 3/4 to 1 inch slab would be perfect. Then break into tumbles with hammer. Or Yesterday a trip to a freight salvage store had glass work labeled Murano for 2 to 3 dollars per pound. Must have been 500 pounds worth. I doubt a kiln will be needed with the availability of art glass May be fake, may not. No matter. It will be hammered into tumbles. Purchased these for $20, 12 pounds of glass. Min. 1/2 inch thick. $100 dollars would keep the tumbler busy for a long time and provide many colors. Maybe someone knows if it is authentic Murano ? MsAli ? Need to see a better picture of the sticker and the bottom of the pieces. I am 99% positive that yes they are Murano pieces. The blue and clear would be a piece from the 70's. The green I need to see more of I should have taken some photos while in the store. The wall was about 50 feet long and shelved 5 feet up loaded with Italian and China glass. The ones with Italian labels had a quality look with bubbles. Not like the rooster. Hey, if I ever sit down long enough to make jewelry I could say they are tumbled Murano if that meant anything.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 2, 2018 9:06:11 GMT -5
The blue and white one is a fake. Although pretty. The green and blue is the one I'm more curious about. Does it have a sticker? Sorry, the green and blue one is labeled China w/about zero bubbles, it is the larger white and blue piece that seems hand made, some serious bubbles in it. I looked at Murano on Ebay and found some pieces that looked like some at the store. Does not mean a thing as they could easily be fakes.
|
|
|
Post by MsAli on Jan 2, 2018 10:17:45 GMT -5
The blue and white one is a fake. Although pretty. The green and blue is the one I'm more curious about. Does it have a sticker? Sorry, the green and blue one is labeled China w/about zero bubbles, it is the larger white and blue piece that seems hand made, some serious bubbles in it. I looked at Murano on Ebay and found some pieces that looked like some at the store. Does not mean a thing as they could easily be fakes. Some real pieces will not have stickers as they came off easily or people peeled them off. There is a catalog of all the houses marks. Murano will have very little to no bubbles or controlled bubbles. They tend to be heavier as well. Bottoms almost always the same. Flat and a perfect circle. Blenko is another to look out for. Some of these pieces are worth thousands.
|
|
|
Post by grumpybill on Jan 2, 2018 10:59:03 GMT -5
Does glass art have embossed Maker's Marks like the soda and beer bottles I collect?
|
|
|
Post by MsAli on Jan 2, 2018 11:23:29 GMT -5
Does glass art have embossed Maker's Marks like the soda and beer bottles I collect? Not a makers mark per se but sometimes a signature of the maker. Depends on the year and who the maker was. The stickers were mainly used to identify House, blower, and year. Stickers changed throughout the years and the new ones that started in 2006? are actually have a code to identify it as real. Blenko is another one that sometimes has a signature but again they used stickers in early pieces for identification purpose. Value increases on a piece if they have an intact sticker and or signature.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 3, 2018 18:32:36 GMT -5
Rooster breast day 6. Early in tumble so it is getting a few small divots from the high speed grind at 63 RPM in an 8 inch barrel w/bulk grit. Next clean out will move to 30 RPM and SiC 50 to remove damage.
|
|
|
Post by MsAli on Jan 3, 2018 18:38:22 GMT -5
Rooster breast day 6. Early in tumble so it is getting a few small divots from the high speed grind at 63 RPM in an 8 inch barrel w/bulk grit. Next clean out will move to 30 RPM and SiC 50 to remove damage. WOW-that is better than I thought it would be
|
|
|
Post by vegasjames on Jan 3, 2018 18:44:15 GMT -5
Really cool looking.
|
|
|
Post by Garage Rocker on Jan 3, 2018 20:01:20 GMT -5
Looking good. Can't wait to see them finished up. Interesting tumbles.
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 3, 2018 20:20:16 GMT -5
Thanks you guys. Been wanting to tumble glass forever. Hope it polishes.
|
|
|
Post by amygdule on Jan 3, 2018 20:36:43 GMT -5
Cock-A-Doodle-Too
|
|
jamesp
Cave Dweller
Member since October 2012
Posts: 36,165
|
Post by jamesp on Jan 4, 2018 6:34:32 GMT -5
The reality of glass. Same piece but dry. Note bruises from aggressive stage 1. Rotary shaping the glass in two stages. The second stage will be in a slow spinning rotary with SiC 60 to remove bruises and chips. May take 2 weeks to remove small chips and bruises in SiC 60.
|
|