Very low temp melting glass? 4 casting

[FosterFire]

Does anyone know of a glass that has an even lower melting temp than the Japanese glass or the Chinese glass sold by ArtCo?

I have a school teacher friend looking for some for a casting project. He is hoping to find some glass with a melting temp of say 200-300 degrees.

(please don't suggest plastic, thank you)

[richsantaclaus]

I think Sataki (sp?) Japanese glass has a COE of 106 and is the softest one can get I am afraid.

[somewhere]

Does anyone know of a glass that has an even lower melting temp than the Japanese glass or the Chinese glass sold by ArtCo?

I have a school teacher friend looking for some for a casting project. He is hoping to find some glass with a melting temp of say 200-300 degrees.

(please don't suggest plastic, thank you)

I guess you must be talking Celsius but that's still only 572F. The short answer is no. The long one would be. You can melt borax with a bunsen burner into a glass but it literally would be water soluble. Moretti and these other super high coe glasses will not stand the test of time. First losing luster then degrading rather quickly into what will look like sand stone. There is no free lunch when it comes to glass.

[FosterFire]

True, there is no free lunch, but it is possible. I have talked to Henry Grimmett who says it's possible and also got one other response saying it's possible but expensive.

From RSimmons:
There are some specialty glasses to which selenium, thallium, arsenic, or sulfur have been added that will melt as low at 260-600F. There are at least three elements on this list that I would highly recommend avoiding. I would also imagine that if you could find a distributor the price would be way beyond what most people would be willing to pay for a school project.
Robert

Maybe someone else knows of another answer?

[somewhere]

Glass is a brittle transparent solid with irregular atomic structure. This is a very loose term and I could think of some that fall into that category. After the valence change of the chemicals involved it would not resemble what most people could identify as glass. Including the above.

Anything with that low of a melting point will be unstable and even if you managed to get it in the mold it won't be identifiable as glass.

If you manage to find something it would be absolutely amazing and you will probably go down as one of the most important inventions of our era. Americans are the inventors of the world why not you. Let us know what your friend uses I'd be curious to hear more.

[menty666]

Given Henry makes glass as a profession, I'd kind of take his word for it.

Does it have to be actual glass? You could make sugar glass and that might be slumpable enough to get the point across.

http://www.instructables.com/id/How-to-make-Sugar-Glass/

Not to mention, sugar shards are less likely to get into some kid's finger or eye.

[somewhere]

Given Henry makes glass as a profession, I'd kind of take his word for it.

Does it have to be actual glass? You could make sugar glass and that might be slumpable enough to get the point across.

http://www.instructables.com/id/How-to-make-Sugar-Glass/

Not to mention, sugar shards are less likely to get into some kid's finger or eye.

Rereading my post I do sound like a jerk. I need to work on my on line personality. Everything is possible my science teacher just laid down to many rules.
BTW: Henry is certainly an authority but I do also make glass as a profession.

[NUBBLET]

I dont know if sugar glass is the same ?

but you could try the hard candy thing , its soft and capable of shaping when hot and then stiffens as it cools till its hard as a rock , then each kid could make an edible sculpture . I always get a kick outta watching them make it .
I imagine you could slump into molds as well , they have molded hard candy .


It may fall into the "loose" definition of glass , it kinda has the same heat and viscosity gradient gig goin on .

[LifeGlass]

Have you seen the 90 coe kits at hobby lobby with a microwavable kiln , used for fusing pendants and such. Not sure if that is maybe what he was trying to accomplish, maybe using his oven?

In other words, not wanting to invest in a kiln?

Maybe that is the angle he is going for.

[FosterFire]

They have a kiln. This is for a science class and I don't know all the details, but they are looking for a special application for the cast glass. *shrug* I got asked as the resident glass "expert"..umm, yeah.

[Greymatter Glass]

with more info on what they're trying to do I could maybe suggest alternative materials, or some glass modifier.

Why not plastic?

What's the final application?


-Doug

[FosterFire]

I don't know the final application. Mostly, right now, the students just want to know the answer to the question of if such a thing exists.

[Greymatter Glass]

So then:

Is it possible to make glass that melts at 200-300º C?
Yes.

Is it commercially produced?
Not in the form you're thinking of...t

Can it be made safely in a classroom?
Maybe, in small batches

Will it LOOK like glass we're familiar with?
Not likely.


...ultimately Glass is just a phase of matter. By definition glass doesn't even contain silica. You mentioned "don't say plastic" but plastic _IS_ by most definitions, a type of glass.

Sugar glass might work for your project.

According to Wikipedia scientists have even made a glass that would melt if placed in a deep freeze; CO2 can be compressed to a glass state.

So rather than asking if a glass can be made to melt at a given temperature, maybe a better lesson before they get into that is understanding what glass is.

How old are the students?

-Doug

[FosterFire]

high school

[Andy P]

I just came across this glass that melts pretty low. Not 200-300 degrees, but..... 132 COE easy flow glass....

http://www.artcoinc.com/easy_flow2.php