Chosing COE

[Dennis Brady]

One of the most difficult decisions glass workers must make is deciding what glass to work. You can’t mix COE and few can afford to have a stock of more then one kind.

There are advantages and disadvantages to each different glass. I’d like to put together a comprehensive article to help glassers decide and request comments and suggestions to add to or amend here:

AMENDED LIST

COE 33 (Borosilicate) advantages
That cool silver glass look at cheap prices
More forgiving of temperature variances
Using clear base for canes makes color go a long way
Ready availability of clear rod and tubing in a wide size range
Colored boro is US made
Very good for organic flowing shapes

COE 33 (Borosilicate) disadvantages
Limited availability of easily worked primary and pastel colors
Limited availability of sheet material
Does not allow the tacked on high definition details that softer glasses allow
Higher temperature requirements to work requires a larger torch and oxygen supply
Not as good as soft glass for fine detail.

COE 90 advantages
Reliable COE consistency
Extensive color selection
Available in sheet, frit, or rod
Extensive technical support
Equally suitable for both torching & kilnforming
Made in the USA

COE 90 disadvantages
Sheet glass more expensive
Sheet glass more difficult to cut
Sheet glass textured and more likely to entrap air
Higher temperature required to melt

COE 96 advantages
Sheet glass less expensive
Sheet glass easy to cut
Sheet glass smooth and less likely to entrap air
Equally suitable for both torching & kilnforming
Available in sheet, frit, or rod
Made in the USA

COE 96 disadvantages
Less color variety then 90 or 104

COE 104 advantages
Extensive color selection.
Low melting temperature
Relatively inexpensive

COE 104 disadvantages
Not as COE consistent as 90 & 96
Limited availability of sheet material
High likelihood of devit when fused
Italian made - price likely to steadily increase

COE 120 (Satake) Advantages
Melts at very low temperature and can be worked without oxygen.
Available with or without lead.

COE 120 (Satake) Disadvantages
Restricted selection
Imported – price likely to steadily increase.

[SteveWright]

Dennis,

That sounds like a great project. One of the exciting new aspects of the 104 glass that has started appearing is the high silver content products. I've seen some amazing beads produced with this stuff. Used to have to go to boro to get this type of result. If I were just starting, this alone would tip me over to 104.

I've also seen some amazing work done with Satake. I would not recommend anyone starting to head that direction, but for a second line of glass, it would definitely be something to consider.

Steve

[lunamoonshadow]

You forgot Kinari too.

[DesertDreamer]

I think an added disadvantage to 90 COE is that it's significantly slower to melt on smaller torches. Not impossible, but not fast, either.

That's assuming this is written to apply to flamework as well as fusing.

[Dennis Brady]

Originally Posted by DesertDreamer

I think an added disadvantage to 90 COE is that it's significantly slower to melt on smaller torches. Not impossible, but not fast, either.

That's assuming this is written to apply to flamework as well as fusing.

For the purpose of selecting COE, I see zero difference between torching and fusing. I agree that the higher temp required for COE 90 is a consideration. I've edited my original list to include that.

[Cosmo]

No love for 33 COE?

[scoutycat]

COE96 has a huge spectrum if you use furnace glass frit and cane, it's just not widely available through cold & warm glass shops. Availability and cost of 104 is a major advantage - just about everyone who sells torching glass carries the whole palette of moretti, and you can get a fairly complete set of colors for 10$/lb or less.

[Paul Ewing]

I'll take a very rough stab at this, but Cosmo or someone else probably has a lot to add.

COE 33 advantages
That cool silver glass look at cheap prices (wow I can't believe we can call Boro color cheap now!)
More forgiving of temperature variances
Using clear base for canes makes color go a long way
Ready availability of clear rod and tubing in a wide size range
Very good for organic flowing shapes

COE 33 disadvantages
Limited availability of easily worked primary and pastel colors
Limited availability of sheet material
Does not allow the tacked on high definition details that softer glasses allow
Higher temperature requirements to work requires a larger torch and oxygen supply

[Dennis Brady]

Originally Posted by Cosmo

No love for 33 COE?

Neither love nor hate. Just different. I agree it should be included in a comparision. Your suggestions would be appreciated.

[Dennis Brady]

Originally Posted by Paul Ewing

I'll take a very rough stab at this, but Cosmo or someone else probably has a lot to add.

COE 33 advantages
That cool silver glass look at cheap prices (wow I can't believe we can call Boro color cheap now!)
More forgiving of temperature variances
Using clear base for canes makes color go a long way
Ready availability of clear rod and tubing in a wide size range
Very good for organic flowing shapes

COE 33 disadvantages
Limited availability of easily worked primary and pastel colors
Limited availability of sheet material
Does not allow the tacked on high definition details that softer glasses allow
Higher temperature requirements to work requires a larger torch and oxygen supply

I edited my original list to add that.

[dogmaw]

Don't forget all us Satake people!

[Dennis Brady]

Originally Posted by dogmaw

Don't forget all us Satake people!

How 'bout you provide the advantages and disadvantages. I'll start and you can add or amend:

Satake COE 120 Advantages
Melts at very low temperature and can be worked without oxygen.

Satake COE 120 Disadvantages
Contains lead
Restricted selection

[Beckah]

I think it is also worth noting which glass is made in the US. Since the dollar is nosediving in comparison to other currencies, I don't think that it'll be long before a basic pallette in Bullseye or System 96 will be competitively priced against the Italian (Effetre, Vetrofond) glass. And aren't most of the boro companies also American companies as well?

[Beckah]

Satake has both leaded and unleaded.

[Dennis Brady]

Originally Posted by Beckah

I think it is also worth noting which glass is made in the US. Since the dollar is nosediving in comparison to other currencies, I don't think that it'll be long before a basic pallette in Bullseye or System 96 will be competitively priced against the Italian (Effetre, Vetrofond) glass. And aren't most of the boro companies also American companies as well?

I agree (and will insert a reference) that Bullseye and Spectrum are American made and thus more readily available at reliable prices. Coloured boro is US made but the clear is imported (except for Pyrex which is too expensive to be considered).

I think the desire by many glassers to incorporate torched and fused work will be a major factor in moving more people to Bullseye and Spectrum. Trying to fuse with Italian is an exceedingly frustrating experience that is unlikely to have any future. Same with boro.

My guess? The greatest market expansion will be Bullseye and Spectrum. The primary advantage to the Italian was low price and wide selection. Both those advantages are eroding rapidly. Boro will remain steady but the greater expense for equipment will seriously restrict market expansion.

ETA....
I expect the desire by many glass artisans to use the same glass for torching, fusing, casting, and blowing will more then anything else determine glass popularity.

[Cosmo]

Originally Posted by Dennis Brady

I agree (and will insert a reference) that Bullseye and Spectrum are American made and thus more readily available at reliable prices. Coloured boro is US made but the clear is imported (except for Pyrex which is too expensive to be considered).

Actually, Pyrex is usually cheaper than Simax, Kimble, or Schott. I don't use it though...

[Lisi]

Now this is JMHO - My experience with Effetre frits or most of the 104 COE frits is that they are blahhh unless of course, they are silver glass frit. Those look like fun. Bullseye frits, seems like the only ones that have any color to them are the Gold Purples, and duh...black. Again, JMHO.

Soooo...to get the gorgeous bright super saturated colors it seems like I would have to choose the Reichenbach, Gaffer, or Kugler line. More expensive, 2-3 times as much as Effetre, but oh well?? What I would like to know about these lines, is what about your typical "base colors", like clear, whites, grey, or black?? Are the clears and whites bubbly and plain hard to work with? Are the blacks pitty and or too easily reduced giving you an unwanted metallic surface??

If these lines carry nice base colors to put these saturated colors on top of, swirled within, or encased within, they would all be worth that extra money. IMHO.

For right now, I use Uroboros with these 96 COE frits, and sometimes the size #0 and #00 in a single thin layer on Effetre. I really don't feel very comfortable with that, even though I have never had a report of a broken bead in 5 years. I have wonkies lying around for years now, and no breakage.

I would love to work with specifically one line and not mix COE's around, ever. I really like Reichenbach because of the rich colors.

[Dennis Brady]

Originally Posted by Cosmo

Actually, Pyrex is usually cheaper than Simax, Kimble, or Schott. I don't use it though...

Interesting. When I checked Pyrex prices it was a lot pricier then the alternatives. I would have thought a US made boro would be more popular - especially if it's cheaper.

[Cosmo]

It doesn't work as well, at least in my experience. It doesn't take fume very well, and encased colors don't come out very well.

[Dennis Brady]

LATEST UPDATE


COE 33 (Borosilicate) advantages
That cool silver glass look at cheap prices
More forgiving of temperature variances during working than soft glass
Allows complex constructions through the joining of separate components.
Using clear base for canes makes color go a long way
Clear rod and tubing available in a wide size range allows for blowing with a torch
Colored boro rods are US made
Exceptional clarity
Clear glass very low cost
Very good for organic flowing shapes
Finished object can be safely used in high heat applications.

COE 33 (Borosilicate) disadvantages
Limited availability of easily worked primary and pastel colors
Limited availability of sheet material
Higher temperature requirements to work requires a larger torch and oxygen supply
More susceptible to devitrification than soft glass.
Not as good as soft glass for fine detail and definition.

COE 90 advantages
Reliable COE consistency
Extensive color selection
Available in sheet, frit, or rod
Extensive technical support
Equally suitable for both torching & kilnforming
Made in the USA

COE 90 disadvantages
Sheet glass more expensive
Sheet glass more difficult to cut
Sheet glass textured and more likely to entrap air
Higher temperature required to melt

COE 96 advantages
Sheet glass less expensive
Sheet glass easy to cut
Sheet glass smooth and less likely to entrap air
Equally suitable for both torching & kilnforming
Available in sheet, frit, or rod
Made in the USA

COE 96 disadvantages
Less color variety then 90 or 104

COE 104 advantages
Considerably more color selection then any other soft glass.
Low melting temperature
Relatively inexpensive

COE 104 disadvantages
Not as COE consistent as 90 & 96 – numerous complaints.
Limited availability of sheet material
High likelihood of devit when fused
Italian made - price likely to steadily increase

COE 120 (Satake) Advantages
Melts at very low temperature and can be worked without oxygen. Great for Hot Head.
Holds heat - longer working time
Available with or without lead content.
Lead content glass melts at low enough temperature no fumes are produced.
Has many colors unavailable in other glass.

COE 120 (Satake) Disadvantages
Melts very quickly and can be difficult to work with regular torches
Less color selection then other glasses.
Imported – price likely to steadily increase.


COE 82 (Float) Advantages
Clear float is the least expensive glass
Armstrong and Youghiogheny have a variety of float fusible sheet glass and frit

COE 82 (Float) Disadvantages
Not as compatibility reliable as COE 90 or 96
Requires higher heat to melt.

[dogmaw]

I would move the "holds heat" on Stake from a disadvantage to and advantage. It makes raking dots so much easier. And if you want your bead to firm up quickly, the trick is to blow on it. That will harden the skin of the bead quite quickly. Also, the color palate isn't really limited. You just need to learn how to work the lead and soda glasses together. Satake has some of the truest pinks and purples around. I've used Satake on a Japanese B-8 torch, hot head, minor, mini cc, and national 8m, all with success.

[Dennis Brady]

Originally Posted by dogmaw

I would move the "holds heat" on Stake from a disadvantage to and advantage. It makes raking dots so much easier. And if you want your bead to firm up quickly, the trick is to blow on it. That will harden the skin of the bead quite quickly. Also, the color palate isn't really limited. You just need to learn how to work the lead and soda glasses together. Satake has some of the truest pinks and purples around. I've used Satake on a Japanese B-8 torch, hot head, minor, mini cc, and national 8m, all with success.

Changes made to above list.

[Dennis Brady]

Completed article now posted:
http://www.glasscampus.com/tutorials...lass%20COE.pdf

[FiredDesires]

Dennis, I believe the coes of Satake range from 113-120, depending if they are the soda or lead version. Still working on the other issue I have concerns with. Keep up the good work.

[Dennis Brady]

Originally Posted by FiredDesires

Dennis, I believe the coes of Satake range from 113-120, depending if they are the soda or lead version. Still working on the other issue I have concerns with. Keep up the good work.

I'm looking forward to your comments. Perhaps a tutorial? I suggest the same for anybody that has a personal preference or recommendation they'd be willing to share.
http://www.glasscampus.com/submissions.htm

[ArtcoInc]

Originally Posted by FiredDesires

Dennis, I believe the coes of Satake range from 113-120, depending if they are the soda or lead version. Still working on the other issue I have concerns with. Keep up the good work.

The Satake soda-lime glass has a COE of 112/113. The Satake lead crystal has a COE of 120. The new Kinari 'C' series soda-lime glass has a COE of 128. I'm also playing with some Chinese soda-lime glass with a COE of 132.

Malcolm

[Dennis Brady]

Originally Posted by ArtcoInc

The Satake soda-lime glass has a COE of 112/113. The Satake lead crystal has a COE of 120. The new Kinari 'C' series soda-lime glass has a COE of 128. I'm also playing with some Chinese soda-lime glass with a COE of 132.

Malcolm

If you keep me informed of your findings, I'll keep the list updated.

[Mr. Smiley]

Hey Dennis... this is all useful information, but why are you gathering here and posting it complete over there? I know you own the other site, but it gets old linking outside to the information when you post it that way... why not post it here as well as there and the people who find you over there will have it too... from a user point of view, I hate having to click the link. It's a simple copy paste sort of thing... do you have something against contributing the information on LE without outside links?

[Dennis Brady]

Originally Posted by Mr. Smiley

Hey Dennis... this is all useful information, but why are you gathering here and posting it complete over there? I know you own the other site, but it gets old linking outside to the information when you post it that way... why not post it here as well as there and the people who find you over there will have it too... from a user point of view, I hate having to click the link. It's a simple copy paste sort of thing... do you have something against contributing the information on LE without outside links?

I have nothing against posting it anywhere but it's a lot more efficient to post a link. There's over 100 articles on Glass Campus. Many are much longer then can be posted on a forum board. One is 60 pages.

Are you under the impression that I gathered all the information here?

[Dennis Brady]

Here's an example of why it's inefficient to cut and paste. The tutorials are prepared as PDF's so they can be printed off and (unlike web pages) the print versions will match the pages on the website. Here's what appears with a cut and paste. Compare it to the page on the website and you'll see that the webpage is considerably easier to read then the cut and paste to the board.

What COE To Chose?
One of the most difficult decisions glass artisans must make is deciding what glass to use. Too
often glass instructors will steer their students to the instructor’s personal preferences.
Flameworking instructors that prefer boro will tell students that's the only glass worth working
with. Those working with soft glass are most likely to tell students they should use 104. That’s
fine if the student is sure they’ll not later want to expand their collection of skills to include
blowing, casting, and fusing. Perhaps more consideration should be given to the greater
versatility of 90 or 96. When a beginner student makes a decision what glass to work with, it
should be a reasonably well informed decision based on their present as well as anticipated
future needs.
You can’t mix non-compatible glass and few can afford to keep a stock of more then one kind.
Some artisans will alternate their work with different makes of glass but most prefer to choose
just one and use it exclusively. Those that are involved only with flameworking are likely to
choose a different glass then those involved only with kilnforming, and those that alternate
working in different methods might make an entirely different choice. Whatever you are doing,
there are advantages and disadvantages to different makes of glass.
COE 33 (Borosilicate)
• ADVANTAGES
Cost Clear glass very low cost
Inexpensive silver glass
Quality Exceptional clarity
Properties More forgiving of temperature variances than soft glass.
Allows complex constructions by joining of separate components.
Excellent for organic flowing shapes.
Finished object can be safely used in high heat applications.
Glass tubing makes for easy glass blowing.
Availability Colored rods made in USA.
Clear rod and tubing available in a wide size range.
• DISADVANTAGES
Properties Higher melting temperature requires larger torch and oxygen supply.
More susceptible to devitrification than soft glass.
Not as good as soft glass for fine detail and definition.
Availability Very limited availability of sheet material.
2
COE 90
• ADVANTAGES
Quality Tested for compatibility.
Excellent technical support.
Extensive color selection in frit, rods, and sheet.
Properties Equally suitable for both torching & kilnforming.
Availability Available in billets, frit, rod, and sheet
Made in the USA.
• DISADVANTAGES
Cost Sheet more expensive then 90, rods more then 104.
Quality Sheet glass more difficult work with.
Textured surface more likely to trap air.
Properties Higher temperature required to melt.
More prone to devitrification then 96 on multiple firings.
COE 96
• ADVANTAGES
Cost Sheet glass lower cost than 90.
Cullet for casting or blowing very low cost.
Quality Probably the most compatibility consistency of all glass.
Consistent texture makes it easiest to work with.
Properties Smooth sheet glass is less likely to entrap air.
Equally suitable for casting, fusing, and torching.
Availability Excellent color variety in frit and sheet.
Most colors available in casting cullet.
COE 96 is the industry standard for most blowing and casting.
Made in the USA.
• DISADVANTAGES
Selection Less rod color selection than 90 or 104.
3
COE 104
• ADVANTAGES
Cost Rods less expensive then 90 or 96.
Quality Excellent for fine detail torch work.
Properties Slightly lower melting temperature than 90 or 96.
Selection Much more rod color selection then any other soft glass.
• DISADVANTAGES
Cost Imported - price likely to steadily increase.
Quality Questionable compatibility consistency.
Very susceptible to devitrification when fused.
Properties Unsuitable for large work.
Selection Very limited availability of sheet material and frit.
COE 120 (Satake)
• ADVANTAGES
Properties Holds heat – longer working time.
Melts at low temperature and can be worked without adding oxygen.
Lead content glass melts at low enough temperature produces no fumes.
Selection Available with or without lead content.
Has many colors unavailable in other glass.
• DISADVANTAGES
Cost Imported – price likely to steadily increase.
Properties Melts very quickly and can be difficult to control with regular torches.
Selection Less color selection then other glass.
4
COE 82 (clear float)
• ADVANTAGES
Cost Clear float is the least expensive glass.
Selection Armstrong and Youghiogheny have a variety of float fusible sheet glass
and frit.
• DISADVANTAGES
Quality Not as compatibility reliable as COE 90 or 96.
Clear float is more susceptible to devitrification then 90 or 96.
Properties Requires higher heat to melt.
Selection Very limited selection of colors.
COE 108 (Schott clear)
• ADVANTAGES
Quality Exceptionally clear – favoured for paperweights.
• DISADVANTAGES
Properties Unreliable compatibility with any other glass
Available only in billets.
Not used for anything other then paperweights.
This list of advantages and disadvantages is intended to help artisans (new and old) decide
what glass to use. There are new materials and new techniques being introduced constantly. If
you have any suggestions for amendments or additions to this list, please let us know and we’ll
update it.