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Yes, I searched the archives.......

Short story: We just fused a full kiln of tiles with the old style BE thin fire under each tile and all the corners have turned up slightly, like oriental shoes.

Long Story: We have been testing our kilns various temps extensively. We found a temp we like for tiles. Our Fiberfrax shelf was pitted so we took it out cleaned it off, put new BE kiln wash on it, fired it. Once this was done it looked like we needed to repeat the wash, but I was anxious to get some tiles done. So I put (old style) thinfire under each tile and fired on a schedule that I have had success with before (minus the thin fire).

This morn when I opened the kiln, every piece had cute (sarcasm) little upturned corners. We will re-fuse, but what! causes this?

Also why does opal BE stick to my Fiberfrax shelf and transparent BE does not? (That's what cause the pits in my shelf.)

Thanks.

Carla

[quote="Carla"]Yes, I searched the archives.......

Short story: We just fused a full kiln of tiles with the old style BE thin fire under each tile and all the corners have turned up slightly, like oriental shoes.


Was it the tiles or the thin fire that turned up its toes?

Jim

I'm making a gazillion pins and magnets and have observed this phenomenon. To increase production, I stopped grinding the base glass which is black, iridized side fired down. I noticed that the corners flipped up and folded over creating a tiny irridized triangle at each former point. Curious. I use BE kilnwash. On my pieces, the corners did flatten out again, but remember, these are smaller pieces than your tiles. Maybe a longer soak?

Just speculating,

Dani

>>This morn when I opened the kiln, every piece had cute (sarcasm) little upturned corners. We will re-fuse, but what! causes this?


Carla,

I use BE ThinFire under fritwafers, some small, some quite large (11" x 11" largest so far). These are fired to 1285*F. Unless I weight the edges of the ThinFire with strips of scrap glass, it will curl up, sometimes warping and curling up the wafer edges. I don't know why it does this (Lani and the BE crew may be able to address this with certainty), but the curling seems to be a function of ThinFire's capacity for shrinking when fired. Perhaps it has something to do with the organic binders and surface tension at certain temps?

Weighting the edges might work for you, but it is likely to eat up valuable shelf space given the expanded spacing.

Good luck,
Kris

Clarifying what turned-up.....the tile corners.

Each corner of the glass tiles is slighly turned up like the toes on oriental shoes.

The tiles ranged in sizes from 1" square to 8" x 6.5". There were 25 tiles total in the kiln.

My top temp was 1400 with a 8 min hold. Since I have done this before with no problem I can only conclude it was the thin fire under each tile. But! I want to make sure. This is indeed a funny look.

I am going to re-fuse em all, minus the thin fire.

It was just so weird. I'd never seen anything like it before. I have used thin fire under one or two tiles (those with opal on the bottom) but never an entire kiln full of tiles.

Oh well. Life is a learning experience.

Carla

You know, there is some extensive discussion about this in the archives.... I wonder if anyone remembers the thread title. Seems like Brock was commenting on the this..... maybe a year ago? Where's Brian, he can always find these lost and obscure threads.

Dani, you could be referring to Brock's infamous "anti-slump" which would be a slightly different and far more obscure phenomenon than the turned up corners. The anti-slump, by the way, has yet to be caught on film . . . is that right Brock? Or did you eventually get pictures?

I've had the turned up corner problem myself, actually, but only with float. Just figured it was another good reason for me to avoid float unless I have to - too many little tricks I don't want to have to figure out when I use it.

Jackie Beckman wrote:Dani, you could be referring to Brock's infamous "anti-slump" which would be a slightly different and far more obscure phenomenon than the turned up corners. The anti-slump, by the way, has yet to be caught on film . . . is that right Brock? Or did you eventually get pictures?

I think there were eventually some photos posted of the anti-slump. I keep peeking, hoping to see it in my kiln. Must be a Canadian thing....

Upturned corners redux:

I have been reading the archives about glue (whatta conumdrum) and found that you should vent your kiln when it has fiber paper or glue in it, because of fumes.

That I did not do. So my speculation is that since I used a lot of old style thin fire and did not vent my kiln, the fumes some how performed some magic and turned all my corners on my tiles up like little oriental shoe toes.

I am lucky enough to live near Bullseye and will share one tile and my theory with them. In the meantime the old style thinfire is outta my kiln.

Carla