Hi All - I know that when you refire a piece (say a tack fuse on first firing and a full fuse on second firing) you should slow down the initial heating period and extend the annealing time, but is there any rule of thumb as to how much slower to go on subsequent firings or how much longer to anneal?
Thanks for any help,
Jaye
Ramp up and annealing on second firing
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Barbara Muth
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Cynthia
Re: Ramp up and annealing on second firing
Your firing schedule will vary according to the glass you are using, the dimensions and particularly the thickness. Many folks slow their schedules down if they are using lots of different colors of glass, or as a rule of thumb for a second firing. You can get away with a fast ramp on a first firing but the glass isn't so forgiving once it's laminated.Jaye wrote:Hi All - I know that when you refire a piece (say a tack fuse on first firing and a full fuse on second firing) you should slow down the initial heating period and extend the annealing time, but is there any rule of thumb as to how much slower to go on subsequent firings or how much longer to anneal?
Thanks for any help,
Jaye
Look up schedules for thicknesses...I believe BE has a firing schedule posted according to the thickness and diameter of glass.
IF you have a specific situation that isn't covered by these posted schedules, give us the specifics and I bet you'll get a less generalized answer.
Hi again-
My process (in this instance) is a tack fusing of several pieces on top of a blank so that I can put frit between pieces (without having the frit run under the glass - sort of like a fused glass mosaic). My question is, once I have successfully tack fused or even fused based on available schedules (as I already do), by how much do you slow the kiln on the second firing. For instance, I usually ramp up at 350 degrees per hour to 1000. On my second firing should I slow it down to 300 or even less? I guess that I have been told a number of times that each subsequent firing should be slower than the previous one (even a slump firing). How much slower is slow enough?
My process (in this instance) is a tack fusing of several pieces on top of a blank so that I can put frit between pieces (without having the frit run under the glass - sort of like a fused glass mosaic). My question is, once I have successfully tack fused or even fused based on available schedules (as I already do), by how much do you slow the kiln on the second firing. For instance, I usually ramp up at 350 degrees per hour to 1000. On my second firing should I slow it down to 300 or even less? I guess that I have been told a number of times that each subsequent firing should be slower than the previous one (even a slump firing). How much slower is slow enough?
i'd probably use some sort of glue rather than having to wait for a firing just to stick the glass down. i've heard of using hot gun glue to do so.Jaye wrote:Hi again-
My process (in this instance) is a tack fusing of several pieces on top of a blank so that I can put frit between pieces (without having the frit run under the glass - sort of like a fused glass mosaic). My question is, once I have successfully tack fused or even fused based on available schedules (as I already do), by how much do you slow the kiln on the second firing. For instance, I usually ramp up at 350 degrees per hour to 1000. On my second firing should I slow it down to 300 or even less? I guess that I have been told a number of times that each subsequent firing should be slower than the previous one (even a slump firing). How much slower is slow enough?
in answer to your question: there's not a specific rate that's good for all applications. you'll have to develop one. there are people on both sides of the camp: some slow down more for each subsequent firing, some only slow down only after the first. in all cases it's highly dependant upon what the maximum thickness is.
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LesleyNolan
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Hi Jaye
Lesley here, I usually glue the glass down so that it won't move. You get very little frit under the glass that way. (Remember, it only takes a tiny bit) However, in some instances, I glue, tack fuse, and flip the piece over and full fuse again to get really tight pieces.
I find that my schedule changes for fiber shelves and ceramic shelves. Fiber tends to allow more speed. I think that is because of the more equalized temperature. 300 is more than slow enough! ( Especially since I know how big your kiln is!) If you are having a problem, give me a call
Lesley
Lesley here, I usually glue the glass down so that it won't move. You get very little frit under the glass that way. (Remember, it only takes a tiny bit) However, in some instances, I glue, tack fuse, and flip the piece over and full fuse again to get really tight pieces.
I find that my schedule changes for fiber shelves and ceramic shelves. Fiber tends to allow more speed. I think that is because of the more equalized temperature. 300 is more than slow enough! ( Especially since I know how big your kiln is!) If you are having a problem, give me a call
Lesley
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Cynthia
I ramp up at 300 dph after the initial fuse for this very type of firing. This is in a top firing fiber kiln with the shelf being 10" below the elements. The piece is 20 inches in diameter.
I was tack fusing first, and for a pristine, no frit except for in between the tiles, that's your best move. I use non aerosol hairspray now and skip the tack fuse on occasion. I don't really want it to be pristine, so a few stray bits of frit are alright by me. Spray your base, just a few square inches at a time, lay down your mosaic tiles and they set up rather quickly. Once they're set up, you can grout with your powder or frit. The hairspray burns off cleanly and without problems.
The downside is that it can be difficult to get the powder off of the surface of your tiles if they are a bit sticky when you apply it.