system 96 - red opal - WarmGlass.com

system 96 - red opal

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bkfoltz
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system 96 - red opal

Postby bkfoltz » Mon Mar 17, 2003 11:08 am

The system 96 - red opal noodles came friday. They seem more orange than red. When I put them side by side with the orange sheet glass they look slightly red but not RED. When I put them next to the red sample from my sample pack the are not the same color.

Have there been problems at Spectrum with red opal?.

Tony Smith
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Postby Tony Smith » Mon Mar 17, 2003 11:57 am

Spectrum has discontinued its red, orange and butterscotch opals for environmental reasons. Uroboros is making the new red and it looks nice after fusing, but looks somewhat transparent before fusing. I haven't noticed that it looks more orange.

Tony
The tightrope between being strange and being creative is too narrow to walk without occasionally landing on both sides..." Scott Berkun

Patty Gray
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Postby Patty Gray » Mon Mar 17, 2003 1:04 pm

I think the process of making stringers is what makes the slight color shift. Melting a full furnace of glass and having to go high in temperature is what causes this. I believe the red stringer is made from the red cathederal not the red opal. You can contact Spectrum or Uroboros on this.

http://www.pattygray.com

Cynthia

Postby Cynthia » Mon Mar 17, 2003 1:58 pm

Patty Gray wrote:I think the process of making stringers is what makes the slight color shift. Melting a full furnace of glass and having to go high in temperature is what causes this. I believe the red stringer is made from the red cathederal not the red opal. You can contact Spectrum or Uroboros on this.

http://www.pattygray.com


Couldn't the volume of the glass make a difference in how it looks too? I can't comment on Spectrum or Uro in respect to Noodles or stringer, but when I pull my own the color dilutes, desaturates...even can appear to change, simply because I've streched it out. Whaddya think?

Also, like Tony said...can't get Spectrum in red opal and other colors anymore, but Uro makes them. Same environmental issues but manufactured in different states? Is that why Uro and BE can make red but Spectrum can't? (regardless of COE).

Lani McGregor
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Postby Lani McGregor » Tue Mar 18, 2003 1:26 pm

“Also, like Tony said...can't get Spectrum in red opal and other colors anymore, but Uro makes them. Same environmental issues but manufactured in different states? Is that why Uro and BE can make red but Spectrum can't? (regardless of COE).â€

Cynthia

Postby Cynthia » Tue Mar 18, 2003 2:38 pm

[quote="Lani McGregor"]
Cynthia, I hope I don’t sound testy – it seems to be a shortcoming of mine (and not the only one!) but here goes: It’s been suggested in prior posts on this subject that BE & Uro can make reds in Oregon because our environmental regulations are more lax. I’d just like to say this is NOT SO. We are hugely monitored on environmental issues here in Oregon, by the same regulatory agency that monitors the entire Northwest territory.

As for why Spectrum quit making fusible reds, oranges etc.: I’m not particularly comfortable answering questions for other companies, but if they aren’t explaining the whole picture, I’m happy to repeat what I heard from credible sources:

Spectrum’s owner (Craig Barker) told our sales manager (Jim Jones) at Glass Craft Expo that they ceased producing those colors not only because of environmental issues but also because they had quality problems in the manufacturing of them.

Anyone in glass manufacturing knows that cad/seleniums are very difficult glasses to make. At Bullseye we’ve made tons of off-color (discounted “curiousâ€

Lani McGregor
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Postby Lani McGregor » Tue Mar 18, 2003 2:58 pm

Thanks, Cynthia, I feel like a first class citizen again. (Who's looking forward to your move our way!)
:D

Cynthia

Postby Cynthia » Tue Mar 18, 2003 6:24 pm

I am looking forward to it too Lani. It will be quite a change from the snows of the Wasatch Front to rain, rose gardens and an ocean nearby. Having BE in my backyard could be dangerous though. I nearly had a stroke last fall, jonesing (I know, drug lingo, but it's aptly descriptive) over the Curious and Saturday glasses available in the warehouse. I'll need a restraining order.

My real curiosity about the original color question though was:

"Couldn't the volume of the glass make a difference in how it looks too? I can't comment on Spectrum or Uro in respect to Noodles or stringer, but when I pull my own the color dilutes, desaturates...even can appear to change, simply because I've streched it out."

Does this seem plausible? Whaddya think?

Lani McGregor
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Postby Lani McGregor » Tue Mar 18, 2003 6:37 pm

Cynthia,

Maybe I'm not sure what you're experiencing: reds being less saturated in color in a thinner section? If so, this seems strange because a curiousity of cad/sel reds, oranges and yellows is that they DON'T reduce (or increase) in saturation like many other colors in relation to their relative thickness.

But maybe I'm not understanding the question?

-Lani

Paul Tarlow
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Postby Paul Tarlow » Tue Mar 18, 2003 6:48 pm

Lani McGregor wrote:Cynthia,

Maybe I'm not sure what you're experiencing: reds being less saturated in color in a thinner section? If so, this seems strange because a curiousity of cad/sel reds, oranges and yellows is that they DON'T reduce (or increase) in saturation like many other colors in relation to their relative thickness.

But maybe I'm not understanding the question?

-Lani


Odd. It seems counter intuitive that a reduced amount of colorant (that must result from reduced amount -- thickness -- of glass) wouldn't yield reduced color saturation. Are you saying that a 3" thick piece of red will look just as red as a 1/8" piece? Or maybe I misunderstood.

I absolutely believe you -- but I'd like to understand better how this is true. Its like those little quantum physic factoids (sub atomic particles that change behavior because you are looking at them) my 16 year old son is always sharing that give me a headache :)

- Always-wants-to-understand-why Boy

Cynthia

Postby Cynthia » Tue Mar 18, 2003 6:50 pm

I think you understand. When I pull my own stingers or cane or do drip lines I often combine colors, so perhaps what I am seeing isn't a desaturation of color but an interaction of the color side by side.

I'll have to pull out some of my stringer bits and drip lines and look at them more closely.

Pete VanderLaan
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Postby Pete VanderLaan » Tue Mar 18, 2003 9:00 pm

opaque reds are not really colors that are happy being made outside of a furnace environment. Transparant reds are much less of a problem. In either glass, the balance of cadmium, sulphur and selenium is critical and goes hand in hand with the furnace atmosphere, On the silicon tetrahedron oxygen and selenium constantly battle each other for a position. The only reason this is important is because selenium can be in five differing states of valence but only one shows good color. As the battle goes on, the color shifts.

Now add white to the basic color and your balance gets to be precarious between orange and liver. It's really hard to do.

Now once it is drawn into a color rod, or a stringer, it is cooled very suddenly and frozen in that state until you heat it up again whereupon it starts to shift all over again. I have never seen a manufacturer capable of continually making a consistently good red opaque without having the pile of colors all around the red that people try to market which are actually cannonized mistakes.
Somedays it works some days it doesn't. Croucher and I used to talk about barometric pressure and making reds and those are actually serious conversations about how thick the air is. No one is immune from disaster.

If spectrum decided to quit the opaque red biz, it is most likely because the return wasn't worth the grief and the seconds.

There are more reliable ways to make reds, like with a zinc potash base glass. They are incredibly beautiful but phenomenally expensive to make and are very touchy about throwing pot stones if overheated even the littlest bit. The only real advice you should take is when you find one you like that actually works, count your blessings and buy it all. Pete VanderLaan

Cynthia

Postby Cynthia » Tue Mar 18, 2003 9:40 pm

Cynthia Oliver wrote:I think you understand. When I pull my own stingers or cane or do drip lines I often combine colors, so perhaps what I am seeing isn't a desaturation of color but an interaction of the color side by side.

I'll have to pull out some of my stringer bits and drip lines and look at them more closely.


Okay. I've pulled out my stringers and such that I pulled myself, as well as a mixed tube of BE stringers. I compared them to the base glass they were pulled from (not the same exact glass, but a sheet of BE red opal, among others. What I am seeing is less of a saturation of color in the stingers I pulled, and the BE stringers...well it's hard to know what glass some of them are supposed to be. They don't all match up with glass I have or from my sample case. It seems logical that it is because there is much less glass there creating a shift in color or saturation, percieved or actual.

A sliver of stringer compared to the 3mm thick sheet of glass and viola, they are different in the level of saturation. This could be optical, but other colors of opals actually start to look a bit transparent...and some transparents become even more greatly desaturated (is that a word?) in appearance once pulled. So I am thinking wether its a physical fact or a visual perception, the volume of glass does change the level of saturation or how it's percieved.

I'm thinking about the images in the current BE catalog of the levels of saturation of a thin (1.5mm) rolled compared to a standard (3mm), and two 3mm stacked to create 6mm of the same glass (pg. 6-7). It's the level of color saturation that is being illustrated on these pages. Granted that is an example of transparent glasses, it makes sense to me that less volume, in particular when you thin out the glass to the size of a capelinni noodle, that there just isn't enough material to maintain the same level of color saturation...

This is interesting. Would love to know more about why a cad sel glass would remain the same saturation regardless of thickness. Like I said, I am no chemist or physicist, but would love to know the skinny. Learning new things every day.

Pete VanderLaan
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Postby Pete VanderLaan » Tue Mar 18, 2003 11:26 pm

opal glasses made with cryolite ( sodium alumina hexafluoride) are packed with crystals . The crystals are either aluminum fluoride or calcium fluoride in thier makeup. There are other types of molecules known as colloidals which simply means big molecules in long strings, and they appear like crystals and do opacify but for different reasons.

When a fluorine base glass is made in the pot and is drawn from the pot on a steel rod, it draws transparent. The crystals form as it cools. If it is a stringer and stringers cool fast, less crystals have time to form before the glass becomes chemically inert and therefore the density of the glass is lower. Sometimes these stringers will develop a better "strike" if reheated and cooled more slowly.

In the colloidals those big molecules that form up reflect light back at you rather than easily allowing the light to simply pass through. They create more of a "fire opal " phenomena. They aren't true fire opals but they look a lot like them.

Gold based glasses which you don't see much of in the fusing arena are colloidal in their nature as well. The goal there is to make lots of tiny molecules. That allows for good color transmission. Sometimes because the gods are angry or whatever the disease of the day is, those glasses make relatively few molecules that are in fact very large. That yields up the phenomena we call "livering", in which those big molecules reflect the light back at you.

And the Cad sel glasses are all terribly subject to the abovementioned conditions. Speak hot and angry words at them and it throws off their color.

Does that help? Pete VanderLaan

Lani McGregor
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Postby Lani McGregor » Wed Mar 19, 2003 12:22 pm

Honestly, I can’t give anyone a technical explanation for why cad/sel reds, yellows, & oranges don’t increase in saturation in relation to an increase in thickness (in the cold sheet) to the degree comparable with most other glasses. From experience I just know that they do.

You can see examples of the phenomenon on pages 8-9 of the BE color catalog where we’ve shown our transparent palette in thicknesses of 1.6, 3, and 6mm. From the pictures it’s obvious that the yellow, red and orange glasses (1120, 1122 and 1125) do not increase in saturation in a way comparable to – for instance – copper blue glasses like 1116, 1108, 1408 etc. etc.

(Cynthia, you’ve referred to our charts of opal glasses on pages 6-7 where we don’t show this stacking of color simply because no opaque glass is going to increase in saturation as it’s layered just because it’s not transparent. So I’m a bit confused there.)

I’ll bug Dan later today and see if I can post something that explains color saturation vs. thickness thing.

I think that Pete’s post on cad/sel glasses – while really interesting – relates more to the primary making of the glass (in the furnace) than it does to the mode in which most of us use it in kiln work. And his knowledge of the difficulties of making reds certainly jibes with ours, in that red opals are far more difficult to produce consistently than transparent reds - and addresses the earlier question of why Spectrum stopped making red opals – it’s just too much trouble for the financial return.

Curiously, for secondary (fusing) usage, the transparent reds are much more problematic than the opals. Transparent reds are more inclined to shift in compatibility on multiple firings than are opal reds.

But, I don’t think that any of us have totally answered Paul or Cynthia’s question about the saturation/thickness issue here. Have we? Again, I’ll see if Dan has some info later today.

Oh well…. if it weren’t such a mystery, we wouldn’t be so addicted, right?

-Lani

PS. Pete, you wrote: “Gold based glasses which you don't see much of in the fusing arena…â€

Cynthia

Postby Cynthia » Wed Mar 19, 2003 12:59 pm

Lani McGregor wrote:You can see examples of the phenomenon on pages 8-9 of the BE color catalog where we’ve shown our transparent palette in thicknesses of 1.6, 3, and 6mm. From the pictures it’s obvious that the yellow, red and orange glasses (1120, 1122 and 1125) do not increase in saturation in a way comparable to – for instance – copper blue glasses like 1116, 1108, 1408 etc. etc.

(Cynthia, you’ve referred to our charts of opal glasses on pages 6-7 where we don’t show this stacking of color simply because no opaque glass is going to increase in saturation as it’s layered just because it’s not transparent. So I’m a bit confused there.)


Perhaps we're looking at different versions of the catalog. In the BE catalog that I have the opals are on pgs. 4-5, transparents are on pgs. 6-7, textures, irids, ring mottles are on pgs. 8-9. Regardless, the examples of saturation compared to thickness in transparents from the chart that I was referring to is the same chart you are referring to. It is well illustrated that the 1120, 1122 and 1125 glasses are strong colors and the saturation appears to change very little with the thickness compared to some of the others. The degree in difference of saturation within the tints is also very slight. Could this be exhibiting the level of base saturation? In the tints (such as 1806, 1820, 1834, 1841) the color saturation is very low to begin with, and in the red, orange and yellow (1120, 1122 & 1125) the base of saturation is very high. Or I should say that is how they appear.

It will be interesting to me to hear what Dan's input is. I probably would be as happy making glass as I am creating with it. You are right Lani that the mystery is partly why I am so intrigued with this medium.

Lani McGregor
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Postby Lani McGregor » Wed Mar 19, 2003 1:52 pm

Cynthia, sorry. Duh. I'm looking at the long version of the catalog. You're looking at the short version (which we call the "brochure") - Lani

:o

Amy Schleif-Mohr
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Postby Amy Schleif-Mohr » Wed Mar 19, 2003 2:27 pm

I am probably butting in here but I just read this thread for the first time.

This could be a random thought and probably isn't related at all but here it goes.
Could there be a connection between the color saturation with red and a black and white photograph of something red reading grey?

Amy
Hopfully someone can explain this...

Pete VanderLaan
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Postby Pete VanderLaan » Wed Mar 19, 2003 11:49 pm

well Lani, I simply said you don't see "much" gold glass in the fusing arena which I still think is true but it's OK to point out that Bullseye has gold glasses ( you are so sensitive).

I am speculating here but a strong possiblility for the strength of the cad/sel density may well be the size of the Selenium molecule. It's big, and big molecules in glass reflect light more than small ones. Couple the Se up with the Alumina/ calcium fluorine and you would expect a dense glass. Pete V

Lani McGregor
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Postby Lani McGregor » Thu Mar 20, 2003 10:29 am

SENSITIVE, ME?????? What are you trying to say, Pete? Go on, spit it out, I always knew you hated us. Jealous that you're not making color anymore and we are?

nyahnyahnyahnyahnyahnyah! :wink:


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