Opals for furnace work ?

[glassmax]

Hi there,

Recently I´ve been working a week with a colleague in a culture park.
He gave some lessons in soft glass bead making there but usually he is working at his own big furnace.
As I am a professional lampworker who has only basic experience in furnace glass blowing and him being a professional glassmaker with not so much practise in lampworkingwe had a very interesting week with glass talks and practise all the time.
So once we came to the question,if there are any of these opals that can be used for soft glass.
I know about these "gilson" opals but as far as I´ve seen,they are all for working with boro.
But we´d like to melt them into soft glass.Are there any opals compatible to soft glass?

Thanks,Axel

[Nicholas Rado]

i don't know a whole lot about opals but nobody else is answering so i did a little bit of research for you. so basically what i found out is that natural opals contain some amount of water in them, which when heated (in glass or otherwise) expands and causes the opal and the glass to burst. synthetic opals however do not contain water and do not expand in glass. from the fact that they don't expand, logically they should be compatible with any CoE of glass. it also seems that the synthetic opals that we use for boro work are simply regular synthetic opals repurposed for glasswork (meaning they weren't designed specifically for boro work, there is special formula of opal that works only in the specific conditions of borosilicate glass).

so id say that they should work. the only concern i can see is if the furnace temperature gets hot enough for them to melt (i couldn't find a specific melting point for synthetics and because they are grown they might be slightly different for each batch or color) but i doubt that will be a problem. even if it is you can put the opals in/on the gather after it is pulled out of the furnace and once its encased in glass it will probably survive the glory hole.

anyway that just about 10 minutes of research and no experience so if anyone has tried it or knows anything about opals that the first page of google doesn't id lean toward their advise. also the second paragraph is really all speculation based on possibly under-informed logic not experience so keep that in mind

[istandalone24/7]

i don't think gilson opals will work with soft glass. afaik, they're not "coe non specific" like dichro extract.

i may have to try it and find though! i've got a bunch of 90coe tubing collecting dust might as well give it a go.

[brads]

[snip] synthetic opals however do not contain water and do not expand in glass. from the fact that they don't expand, logically they should be compatible with any CoE of glass.

Nicholas, your "logic" is faulty. One - just because an opal doesn't contain water doesn't mean it has zero expansion. Two - just because something has zero expansion doesn't make it compatible with a higher expansion glass. If you doubt that, try making a successful seal directly between fused silica and any common soft glass used for lampworking. Good luck... (While the expansion of fused silica isn't absolutely zero, it's close enough for this example.)

[istandalone24/7]

if you go over to LE (lampwork etc) there is a free tutorial on how to make "fire opals" out of reduction/striking glass and silver foil. they look KILLER when done proper and it's a free tut.
i think if you were to make some "fire opals" and then anneal them and just use them like you would a gilson you'd be good to go.

this is the "on mandrel bead lady tech" but hell just use this same tech on punty....like small marbles or even one big cane you can section down.
http://www.lampworketc.com/forums/sh...ght=fire+opals

[Nicholas Rado]

Nicholas, your "logic" is faulty. One - just because an opal doesn't contain water doesn't mean it has zero expansion. Two - just because something has zero expansion doesn't make it compatible with a higher expansion glass. If you doubt that, try making a successful seal directly between fused silica and any common soft glass used for lampworking. Good luck... (While the expansion of fused silica isn't absolutely zero, it's close enough for this example.)

like i said that, i really don't have huge knowledge about opals. just did some short research because there was no replays after two days and i wanted to help. thats what i came up with so thanks for the correction. its is good for me to know for the future and corrects what is apparently not very good info that i gave to the op so thanks for informing me

would it have been better to not give advice about what i wasn't 100% sure of? maybe, but then we might not have had all the replays wight he right answer to correct me :D

[brads]

would it have been better to not give advice about what i wasn't 100% sure of?

In my personal opinion, yes, it's better to keep quiet when you don't know what you're talking about. I'm not trying to be a dick about it, but if you hadn't been corrected, then anyone else seeing your post who didn't know better might believe what you said and pass it on to others. That's how shitty "information" becomes "fact" in some circles. The classic, "I heard it from three different people on the internet, so it must be true".

Bad advice is very often worse than no advice at all.

[glassmax]

Hi all,

Thanks to everybody for your answers.
Nicholas,thanks for your try to help.It´s all right because you noted that you´re not sure if your Infos are correct.
Well,because I have some 30 years experience at the torch(soft and boro glass) I already
know that its all about COE and this is the reason why it´s not possible to mix glasses with opals if they have different COE´s.
So it makes sense to make these opals itself.Unfortunately I cannot open the link to this vid
http://www.lampworketc.com/forums/sh...ght=fire+opals
Is there anotherone ?

If we get to any furnace work with this in the future,I will show the pics for sure.

Greez,Axel

[istandalone24/7]

This one will come without photos because I want you to play with your glass!

You need:

1 rod of Black
1 sheet of silver foil (I cut mine into strips about 10mm wide, 1 strip per bead)
1 rod of DoubleHelix Ekho
1 rod of Clear (your choice) - I use Lauscha Soft Clear


1) Make a base bead of Black.

2) Wrap the bead in silver foil. Burn off the foil at the edges of the base bead but leave it intact as much as possible on the rest of the bead.

3) Use Double Helix Ekho and wrap it around the base bead in a random pattern twice. Leave some silver showing! The trick with the Ekho is to let the tip of the glass go completely clear before you make your swipe. This creates the intense fire color you need over your silver. So let the tip go clear, then swipe the right side. Let the tip go clear, then swipe the left side.

4) Keep the edges of the bead warm (at the mandrel) while melting your choice of Clear glass then encase the entire bead with your favorite method.

5) From here shape as desired.

Voila! You now have a Fire Opal!

[istandalone24/7]

that's just a cut and paste from lampwork etc. that's also a pretty good website for info. beware....bead ladies can be just as harsh as some of the people here lol..