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Everything I read says to fire shelf paper first. My supplier said no, because it reduces the amount of times you can use it. So, if I'm using it on the shelf, what do I do? And, if I'm using it to create a hole, as in a pendant for cord to pass through what do I do? Two different applications, so two different answers? What about burning off the icky stuff (technical term)?
Sandpiper

What kind of fiber paper? Assuming we're not talking about thinfire (which never needs to be pre-fired), but are talking about standard fiber paper formulations, then here are the guidelines I would use.

If I'm using a small amount, like for a hole in a bead or to line a dam, then I would not prefire. If I'm using the paper to line the kiln shelf, then I would prefire. You can get away without prefiring on the kiln shelf, but it has the potential to discolor the glass or cause devit like streaks -- that's a risk I'd prefer not to take.

As for not pre-firing in order to get more firings out of the paper, I doubt this very much for any paper other than thinfire and would love to see your supplier's proof. There are so many other factors that impact paper longevity (type of glass, type of paper, temperature fired to, etc.) that prefiring or not prefiring probably has no significant impact on longevity.

Sandpiper wrote:Everything I read says to fire shelf paper first. My supplier said no, because it reduces the amount of times you can use it. So, if I'm using it on the shelf, what do I do? And, if I'm using it to create a hole, as in a pendant for cord to pass through what do I do? Two different applications, so two different answers? What about burning off the icky stuff (technical term)?
Sandpiper

In my experience, the problems cone when you trap carbon under the glass and the gasses can't escape. It leaves a black scum. This only happens on large areas of glass. 12"-16" wide is usually OK for me. Wider than that has caused problems. It is a crap shoot. If you don't prefire and see black scum, you know what happened.

Thanks much. Well, here we go, Sandpiper's going to try again. Hope the kiln gods grant me a goodie. I need one.

I use fiber paper all the time (not thinfire) I long ago quit pre-firing but I do vent with door cracked up to 700 - 800 degrees. Never had any problem with black or devit. However, don't do many pieces over 14".

I handle my paper very gently, flip it over for each firing, and get a lot of firings per piece.

Diane A

Don't you find that the piece of glass leaves an indent in the fiber that shows up on the next piece? My 1/8" paper is good for at least 4 firings before it starts to rip up, but that indent is a problem. I even tried taking a rolling pin to it to smooth it out, but that didn't work either.

Sandpiper wrote:Everything I read says to fire shelf paper first. My supplier said no, because it reduces the amount of times you can use it. So, if I'm using it on the shelf, what do I do? And, if I'm using it to create a hole, as in a pendant for cord to pass through what do I do? Two different applications, so two different answers? What about burning off the icky stuff (technical term)?
Sandpiper

There usualy never is one answer

Utalising cunning U can take a lot of short cuts n still come out with good stuff

Pre fire at a low temp till smoke burn off vented



If U wanna do a once fire fire realy slow n vent

Once u got the hang of it it is possible U could soak at the burn off temp

Another thing is 2 use small bits of glass / string / wood 2 lift up the glass a little

U realy gotta kinda forget everthing then come back at the problem

I do not use this thin fire stuff

Lynne

I rarely get an indent - and almost always can get rid of it by flipping, rolling with a rolling pin, flipping again. But I vary my pieces, one side of paper for the texture on the back of the piece, then the next piece is on the smooth side.

Diane