Cooling glass in home oven???
Moderators: Brad Walker, Tony Smith
Cooling glass in home oven???
Hi again everyone. My kiln is still a problem, as I have not had it fixed yet. (firebrick mortar has not yet arrived) I have, however, found a way to fuse glass that works for me. I have only lost ONE piece out of 6!!! I am slowly heating the glass with a torch, (on top of a brick) and manipulating it until I am happy with it. Then, I am leaving it under low torch heat for about 5 minutes or so, and then covering it with a small terra cotta pot set upside down over the glass directly on the brick. I try to make sure the pot has a drain hole, which will serve as a "vent" for the hot glass. ( I Assume this is necessary???) I am then putting the entire brick into my home over, preheated to about 500 degrees, and slowly ramping the temperature down from there. I know it sounds "primitive", but so far, it is working! I still have a couple of questions. Number one...being that I am melting the glass on a brick, the back comes out rather "lumpy". It is no big deal, but I am wondering what else I could heat the glass on that might give a smooth finish on the back? I tried my graphite soldering block, but it caused cracks in the graphite, which I DO NOT want. So, I moved to a brick. The brick also seems to hold heat, allowing me enough time to transfer the glass into my oven without damage. My second question is...If I were to go back to melting the glass in the kiln, could I carefully remove the glass at say, around 500 degrees, and then transfer it to my regular oven to ramp it down to room temperature? I LOVE the look of my glass melted in a kiln, but was getting cracks due to my kiln cooling too quickly. (see previous post.....cracks.....ARGH!) I am melting the glass in the kiln on small terra cotta drain pots, made to go under houseplants. They are just barely starting to crack. Is there something else I should use? I heard putting bricks in the kiln is a BAD IDEA....so I have not done it. Any further thoughts on any of my questions or methods here? I have only been learning how to fuse glass for a few days now, and need all the advice I can get. Thanks in advance, once again! Molly.
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BobB
smooth finish
Hi Molly, see what glassworking has done to you? It's addictive and everyone here understands your pain. Don't give up and keep trying new things.
I would consentrate on getting your kiln working or a replacement. There are lots of ceramics/pottery people out there who purchasede a kiln and it's been sitting in thier garage, basement or where ever and would love to sell it and some really cheap. Keep your eye open for a good deal on a used kiln. The reason I say this is in the long run you aren't going to get repeatable results from the method you are using. Yes you can play like this and learn a few things, but you are going to be limited in what you can do. You can try getting a smooth layer of kiln wash over the brick to get a smoother backside. Stainless steel is a good material to fuse on provided it's kiln washed or the glass will stick.
With your oven set at 500 and dropping the temp isn't giving you a good annealing cycle. Annealing should really begin at 980 to 1000 and slowly (200 dph) ramp down. I'm worried how fast you drop from 1000 to 500 but am amazed you've only had 1 of 6 pieces crack.
You can buy furnace/fireplace cement at Lowes or Home depot, but from what I know so far sealing your kiln isn't going to be the complete answer. You'll probably do better, but a good controller to drop your temp at a more even rate is what you need. Some of the glass kilns made of the soft firebricks are effecient enough you can just turn them off and they'll drop/cool off at a good annealing rate. I think someone had mentioned wrapping your kiln in frax. That is a very good idea and should help. Without a controller you're going to have to insulate, insulate and insulate until you get a good 200dph drop from 1000 down to room temp.
Good luck
BobB
I would consentrate on getting your kiln working or a replacement. There are lots of ceramics/pottery people out there who purchasede a kiln and it's been sitting in thier garage, basement or where ever and would love to sell it and some really cheap. Keep your eye open for a good deal on a used kiln. The reason I say this is in the long run you aren't going to get repeatable results from the method you are using. Yes you can play like this and learn a few things, but you are going to be limited in what you can do. You can try getting a smooth layer of kiln wash over the brick to get a smoother backside. Stainless steel is a good material to fuse on provided it's kiln washed or the glass will stick.
With your oven set at 500 and dropping the temp isn't giving you a good annealing cycle. Annealing should really begin at 980 to 1000 and slowly (200 dph) ramp down. I'm worried how fast you drop from 1000 to 500 but am amazed you've only had 1 of 6 pieces crack.
You can buy furnace/fireplace cement at Lowes or Home depot, but from what I know so far sealing your kiln isn't going to be the complete answer. You'll probably do better, but a good controller to drop your temp at a more even rate is what you need. Some of the glass kilns made of the soft firebricks are effecient enough you can just turn them off and they'll drop/cool off at a good annealing rate. I think someone had mentioned wrapping your kiln in frax. That is a very good idea and should help. Without a controller you're going to have to insulate, insulate and insulate until you get a good 200dph drop from 1000 down to room temp.
Good luck
BobB
Thanks for the advice. I am looking for another kiln, but $ is a big problem. We are going to TRY to fix mine, but I only hold a bit of hope for it. When I did my last fused glass in the kiln, it melted BEAUTIFULLY....all colors were fused into ONE "puddle" of glass. But when I let the kiln cool on it's own, and opened the kiln that night, the glass was completely cool, but cracked. One piece only cracked along one side. I was told the kiln does lovely pottery, but I have not tried that yet. I have some pottery pieces drying now. Can u tell I want to learn to do EVERYTHING I am interested in? LOL! I may try to do more fused galss in the kiln, and then transfer it to my home oven once the pyrometer reads about 550 F. Worth a try, anyway! Will fix the firebrick on the kiln too, but Fiance syas it is not a good idea to try and install a controller to this particualr kiln. There is NO indication of amperage, and nothing that gives a brand name or any information on it. I am beginning to wonder if it might be a "home made" kiln. It certainly reaches 1500 degrees, though. Fiance is afraid we might be causing more problems installing a controller without knowing the amperage of the kiln. I suppose there is no real way to tell??? (These things are HIS "area" of expertise...NOT MINE!) Anyway, thanks so much for all the help, and I will keep you posted as to what happens next! LOL! "Tune in for the ongoing saga of Molly and the broken glass"!!!.....
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Clifford Ross
- Posts: 68
- Joined: Sun Mar 09, 2003 10:08 pm
- Location: Myrtle Beach, So. Carolina
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Controller capability.
Look at the breaker panel. Get a controller that will switch the max amperage of the circuit breaker on the circuit where your kiln is plugged in. If the kiln drew more than that - the breaker would be popping all the time.
While not as clean as knowing the actual draw of the elements, it would at least get you going without the likelyhood of burning the controller.
If you are still concerned, get the controller and have it control a relay rated the same as the breaker on the circuit you are plugged into. The relay will only use a very very small amperage draw on the coil, and the load will be within the design of the relay.
JimV
While not as clean as knowing the actual draw of the elements, it would at least get you going without the likelyhood of burning the controller.
If you are still concerned, get the controller and have it control a relay rated the same as the breaker on the circuit you are plugged into. The relay will only use a very very small amperage draw on the coil, and the load will be within the design of the relay.
JimV