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Re: Matte slumped pieces

Posted: Wed Jan 02, 2013 5:16 pm
by Rick Wilton
Yes I find devit DOES depend on the thickness. The glass wants to be 6mm thick, so 3mm will contract as it tries to become 6mm, is this why 3mm glass devits? I have no idea, it could be volume of glass vs. surface area. If you take 1 sqft of glass at both 3mm and 6mm you have twice the amount of glass with virtually the same surface area exposed to air with the 6mm

The long and the short of it is anything less than 6mm behaves very different in my kilns. So much so that I won't even bother messing with it as it's too much of a hassle.

Re: Matte slumped pieces

Posted: Wed Jan 02, 2013 6:15 pm
by Bert Weiss
There is no such thing as float formulated for fusing. Youghiogheny formulates their fusing glass to fit one particular float. The good news with float is that the process lends itself to consistency, so the batch has a lot to do with the outcome. Each company goes about their formulas on their own. I think it is safe to say from collected observations, that different float glasses behave quite differently, especially relative to devitrification. Also some glasses have a heavier tin coating than others. You can see this with the short wave UV lights. Some glasses are easy to detect and others are more subtle (this can also depend on ambient light in the room).

I too have made the determination to not work with float glasses thinner than 6mm when kiln carving or fusing. I simply like my results much better that way. I once got a stash of cheap 5mm glass. In the end, I use it for pattern making, not for kilnwork.

Cleanliness can be deceiving. For instance, in the USA, if you clean glass with Windex, it can look perfectly clean, but the kiln firing will leave marks.

I agree with Cynthia about borax creating more problems than it solves. Although,I have found applications where It really helps. Particularly when I am refiring kiln cast broken tempered, and I want to retain transparency. You do have to keep it off of the bottom and the edges, though.

Re: Matte slumped pieces

Posted: Tue Jan 08, 2013 5:48 am
by Eric Baker
Hi Cynthia,

I'm not familiar with float, being a bullseye fuser, but your results in that piece are intriguing. I'd love to see your final results, if you can/care to share.

warm regards,

Eric

Re: Matte slumped pieces

Posted: Sun Jan 13, 2013 1:59 pm
by twin vision glass
Oh she is beautiful Cynthia. So organic almost. Les

Re: Matte slumped pieces

Posted: Thu Apr 04, 2013 8:57 pm
by Mike Griffin
seachange wrote:Hi

In 2011 I did a lot of tests with float glass, and regularly removed the tin side by soaking the flat piecesfor about 30' in a flat tray filled with CRL water spot remover - a tip that I picked up here on this board. One can see a very very pale sediment in the liquid after this treatment. The liquid is reusable many times, I kept the used one in a separate bottle and added some fresh to it once in a while.

Tin was not detectable with the UV light after this. Did remember Bert's advise that the tin side can be your friend, depending on use.

At the time was making woven plates, flipping the bars, then slumping, so did not want any compression marks.

Hope this helps

Best regards, seachange
CRL themselves say that Water Spot Remover is only suitable for glazing professionals to use and not for consumers. It contains hydrofluoric acid which is indeed a dangerous chemical since it penetrates tissue through the skin and upsets the calcium balance in the blood which can in extreme cases result in death. It causes delayed and painful burns so you don't know that you've been exposed for some time after the event. A laboratory worker in my state spilled a few hundred ml of concentrated hydrofluoric acid on his leg and though he ran outside and jumped in a swimming pool he died some days later. I don't know how much is in Water Spot Remover but I'd stay away from it unless you were appropriately trained and have calcium gluconate ointment on hand in case of contact.

Re: Matte slumped pieces

Posted: Wed Apr 10, 2013 7:40 pm
by Buttercup
Mike, thanks for posting that warning. I was thinking of buying some CRL. Jen

Re: Matte slumped pieces

Posted: Wed Apr 10, 2013 10:37 pm
by Don Burt
cool casting Cynthia

Re: Matte slumped pieces

Posted: Wed Apr 10, 2013 11:50 pm
by Kevin Midgley
embrace the result you have Cynthia.
I would not mess with it.
It is easier to refire a new one.