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Casting with window glass (a.k.a. float galss)

Posted: Mon Sep 08, 2003 2:22 am
by rskrishnan
Hello All,

I've been casting for about 3 years now - mostly with BullsEye frit/cullet/broken up sheet fragments. I've also used Gaffer occassionally - mostly avoid it because of Lead content (paranoia ??).

I've -THOUGHT- about using window glass for casting. I have slumped with it and it is a MUCH harder glass to work with, higher temps, devitrifies easily, and does'nt seem half as cooperative as BullsEye or Gaffer.

My reasons to switch are primarily for $$ reasons - my bank acct seems allergic to splurges in this economy, butmy heart is set on catsing glass! Gaffer is almost as expensive as BullsEye (though a much easier galss to deal with).

It would save me a lot of heart-break if some of the master-casters could post their opinions/experiences/ideas on casting with window glass.

How do you make it flow well ? How do you colour it ?

Also - I expect to get "scrap" from the local hardware store - they throw out a garbage can full every week - which is PLENTY of casting supply for me! So should I worry about compatibility problems since the scrap could be diff manufacturers/diff batches/diff thicknesses etc

Thanks,
Krishnan

Posted: Mon Sep 08, 2003 10:27 pm
by Bert Weiss
Float is a piss poor casting glass.

Posted: Tue Sep 09, 2003 2:09 am
by rskrishnan
Bert Weiss wrote:Float is a piss poor casting glass.
Well there's a resounding DON'T if I ever heard one !!

Krishnan

Posted: Tue Sep 09, 2003 11:35 pm
by Bert Weiss
rskrishnan wrote:
Bert Weiss wrote:Float is a piss poor casting glass.
Well there's a resounding DON'T if I ever heard one !!

Krishnan
Colin of Spab fame has done some successful casting with float. Maybe he can elaborate on what he did. Float glass is not formulated to flow like BE, Spectrum, Gaffer, or various lead crystals. Only bottle glass is worse.

Posted: Wed Sep 10, 2003 3:07 pm
by jerry flanary
Start small and make small mistakes
Try a batch of small tests that have successively higher amounts of flux.
take notes
see if adding a flux helps out.
I think you could try borax or similar. Wet the glass add flux. stir for even distribution. Let dry or not
Take notes..
Report back here
Do not fail us, little one,
May the glass be with you.
j.

Posted: Wed Sep 10, 2003 6:52 pm
by Laurie Young
Another cheap alternative is Ballentini beads, however they have their problems too. They are a small glass sphere (comes in size from powder to about 10 mm) used as an industrial abrasive. You can color them with oxides or powders, in my (very limited) experience they are quite brittle when cast- but I have not done enough work with them to know if that is a result of my firing schedules. The upside is that they are cheap- 25 kgs for $35.00 over here.

Posted: Wed Sep 10, 2003 7:49 pm
by jerry flanary
Also, I got some glass beads that are used for petroleum clean-up or filteration that look pretty interesting- clearish spheres a little bigger than a pea. I suspect that these beads are one of the many products made from recycled bottle glass but I want to make something w/ them just to see. Got them from a Monash student...
j.

Posted: Thu Sep 11, 2003 7:00 pm
by Laurie Young
would that be Ruth? She and I got samples of all the sizes and powders and ran a bunch of tests on them- I have done a couple larger projects, but one bowl crumbles about six months after manufacture for no reason.

Posted: Thu Sep 11, 2003 8:25 pm
by jerry flanary
It was Fiona.

I have done a couple larger projects, but one bowl crumbles about six months after manufacture for no reason. Is this one bowl that you have made several times or a typo? Do you think the glass comes from bottles? How did it behave for you?

j.

Posted: Fri Sep 12, 2003 1:34 am
by Laurie Young
sorry I wasnt clearer_ it was one bowl that was sitting around my studio and broke when I picked it up- It wasnt very thick though, and it was with the 2 mm beads, we have had more sucess with the larger beads. It may not have had enough flux as well. I did a fairly large cast piece, about 50cm X50 cm X 15cm and it was very brittle too, it had different sizes of Ballentini beads mixed up in it in it

Posted: Thu Sep 18, 2003 6:16 am
by brenpage
I have used float a bit to cast with, mostly for students doing "open face" castings. It can work ok but I suggest the following:

- Avoid using float form different sources, even one shop. If the glass comes from different manufactures it can be differnt enough to cause a problem.

- Float won't cast nearly as well as crystal or BE, so plan your forms to be more contained to themselves, avoid extreme undercuts and long drops...in short keep it simple, it does not like to flow too much.

- I fire much higher than I do for other sorts of castings and quicker to avoid devit. Once over about 600c I fire as fast as I can to 920c and only soak for about 15mins. This means your mould will have to be make well.

I have never tried to colour float in a casting, if you avoid devit the colour and density are really quite beautiful....but good luck polishing it.

My the kiln gods be with you
Brenda

Posted: Sat Sep 20, 2003 6:46 pm
by rskrishnan
brenpage wrote:I have used float a bit to cast with, mostly for students doing "open face" castings. It can work ok but I suggest the following:

- Avoid using float form different sources, even one shop. If the glass comes from different manufactures it can be differnt enough to cause a problem.

- Float won't cast nearly as well as crystal or BE, so plan your forms to be more contained to themselves, avoid extreme undercuts and long drops...in short keep it simple, it does not like to flow too much.

- I fire much higher than I do for other sorts of castings and quicker to avoid devit. Once over about 600c I fire as fast as I can to 920c and only soak for about 15mins. This means your mould will have to be make well.

I have never tried to colour float in a casting, if you avoid devit the colour and density are really quite beautiful....but good luck polishing it.

My the kiln gods be with you
Brenda
Good to know that someone has had some success with casting float glass. I'm sick of BE's finickiness - but can't afford Gabbert or other crystal glasses. Will give this a shot in the next month or so - once I'm done making my kiln controller !! Looks like I'm overhauling all my equipment and my materials and my "process" all in one big GO !

Krishnan