stressed glass

[suzanne]

If anybody has any ideas on this one, that would be grand.


I was firing some recycled glass and at 1423F one of my molds seriously cracked and I had to shut down the kiln (the glass and clay mold bits where tipping towards one of my elements). I crashed cooled to 1050F , closed the kiln door and then let the kiln cool down on it's own to room temp.

The glass did not go through the proper anneal cycle.

So..

If I re-fire the glass, taking it through the proper anneal cycle (it is about 3/4" to 1" thick), will the glass be OK or is it forever stressed and therefore not usable?

Suzanne

PS as an aside, just when the clay mold cracked in several places, a building wide fire drill took place...It was serious pub time after that...

[Bert Weiss]

If anybody has any ideas on this one, that would be grand.


I was firing some recycled glass and at 1423F one of my molds seriously cracked and I had to shut down the kiln (the glass and clay mold bits where tipping towards one of my elements). I crashed cooled to 1050F , closed the kiln door and then let the kiln cool down on it's own to room temp.

The glass did not go through the proper anneal cycle.

So..

If I re-fire the glass, taking it through the proper anneal cycle (it is about 3/4" to 1" thick), will the glass be OK or is it forever stressed and therefore not usable?

Suzanne

PS as an aside, just when the clay mold cracked in several places, a building wide fire drill took place...It was serious pub time after that...

Suzanne

If you reinvest the glass and heat up slowly to the softening point, soaking so that the whole section of glass is soft, then reanneal, you will be just fine.

I'm going to guess that you used too much water (same as not enough plaster mix) so that the mold was not strong enough.

If your recycled glass is bottle glass, it is not well suited to casting as the glass formula is designed to harden up quickly after the bottle is formed. The rest of the casting process is so labor intensive and costly, that trying to save money on glass may be not so effective. If you are recycling your broken BE tested compatible, There are no negative issues.

[suzanne]

Thanks Bert!

I spent so much time cleaning the bits I wanted to be able to salvage the glass.

My usual ramp for this type of glass is 450F/hr to 900F then 900F/hr until the fuse point. So I will slow down the ramp to 350/hr to 900F, then 800F to fuse point.

It is window glass (thicker than float) and the mold was low fire (1945F) terra cotta clay (I use these for open face molds - organic shapes). It is the second time my larger molds made from clay busted... However this particular bust up was quite spectacular! I think I overloaded the kiln with too many pieces and probably ramped to fuse too fast and stressed the poor thing into bits...


Cheers and thanks again,

Suzanne

[Bert Weiss]

Thanks Bert!

I spent so much time cleaning the bits I wanted to be able to salvage the glass.

My usual ramp for this type of glass is 450F/hr to 900F then 900F/hr until the fuse point. So I will slow down the ramp to 350/hr to 900F, then 800F to fuse point.

It is window glass (thicker than float) and the mold was low fire (1945F) terra cotta clay (I use these for open face molds - organic shapes). It is the second time my larger molds made from clay busted... However this particular bust up was quite spectacular! I think I overloaded the kiln with too many pieces and probably ramped to fuse too fast and stressed the poor thing into bits...


Cheers and thanks again,

Suzanne

Suzanne

Can you post some pictures of successful work using this technique. I am chuckling as I have quite a bit of heavy glass scrap that goes to the dump and gets recycled in to asphalt.

[suzanne]

Hi Bert

Well the success is still in the making. I'm currently just working on some new pieces for the current series. The foray into recycled float is relatively new for me, so when they are done I will pop you an email to let you know what worked and what did not...

With your work, do you mostly use recycled glass?

I checked out your web site and it is very cool. I really like the glass bar!

Cheers

Suzanne

[Bert Weiss]

Hi Bert

Well the success is still in the making. I'm currently just working on some new pieces for the current series. The foray into recycled float is relatively new for me, so when they are done I will pop you an email to let you know what worked and what did not...

With your work, do you mostly use recycled glass?

I checked out your web site and it is very cool. I really like the glass bar!

Cheers

Suzanne

Suzanne

Mostly I use new sheet glass which I buy in 2 ton cases. I sometimes get salvage glass from a factory. They actually throw away 3/16" x 36" x 72". Beats me??

I'd love to try and re-fuse corn from the tempering factory, but I think it is too mixed up. There is probably starfire mixed in with regular float.

I make my own frits from scrap, which I have a great deal of. I have to keep taking it to the dump or it would overwhelm me more than it does already. I'm not the type of guy to throw everything away. It's a struggle for me.

[suzanne]

I know what you mean about throwing out bits...As soon as you get rid of it, you need it.

But for all your extra glass? If it is mixed then a fusing job , as you pointed out, would be nixed. However if you have a bottle of glue and some mortar well here is a kitchy idea for you...have you ever heard of the glass bottle house? I saw it years ago when I was in Prince Edward Island.

the photo here on this link gives you an idea but does not do it justice....

http://www.travelin-tigers.com/ztravel/can12.htm

Cheers

Suzanne

[charlie]

I make my own frits from scrap, which I have a great deal of. I have to keep taking it to the dump or it would overwhelm me more than it does already. I'm not the type of guy to throw everything away. It's a struggle for me.

in my area they collect scrap glass and grind it up to mix in road construction materials.

if you have a lot of it, get a commercial grinder and sell it on the net as float frit.

[Jerry]

Bert said; "in my area they collect scrap glass and grind it up to mix in road construction materials."

Guess that's why taxes in NH are as low as they are. Imagine all the extra tire sales they get from folks driving on roads made of broken glass!

Yeah, I know, I'm the guy that worries if eating frozen crabmeat is rough on your teeth!

CU in DC

Jerry

[Bert Weiss]

Bert said; "in my area they collect scrap glass and grind it up to mix in road construction materials."

Guess that's why taxes in NH are as low as they are. Imagine all the extra tire sales they get from folks driving on roads made of broken glass!

Yeah, I know, I'm the guy that worries if eating frozen crabmeat is rough on your teeth!

CU in DC

Jerry

The reason I don't have to pay to leave my glass at the dump is that it is sold to the road guys for ashphalt. BTW my dump is in Maine. My town contracts with Fryeburg for use of the dump. You have to pay for everything but recyclables. This does keep taxes lower. They used to sell it back to the bottle makers as cullett for like $25/ton. I'm glad there on to the asphalt guys who accept my float scrap. Take a look at the new asphalt they are laying down this summer, I bet it glistens in the sunlight.

My glass sheets are 48" x 130" so they generate quite a bit of waste. I try and keep it isolated by the case, although 10mm from the same factory has been compatible. My 10mm is not compatible with the 6mm that I have.

CU in DC