The Cullet Wars: Will Anyone Win? Probably not the Artist

[Administrator]

I recently received the email flyer from HotColorGlass that Kugler is going to offer a clear cullet. The price is a little staggering at $1.60/lb. I paid $1.00/lb for Cristalica the last time it was available. Pete has revealed that at least 2 other cullets will soon be available. This is getting really tough. Obviously, these companies all see an opportunity but are they in it for the long haul? Do they even really know? Things seem to happen when you try and melt, cool and cut (or vise versa) hot glass on an industrial scale. Who do you cast your lot with?

Batch makes sense to me but it sure has drawbacks.
- dust issues
- volume loss
- time to melt, time to charge
- the RIGHT formula question

Of course, the final point is true of cullet also. You can always mix your own and I've been playing with the idea. My first attempts just didn't stand up to the clarity of Cristalica. Perhaps barium is the answer to clarity.

Allow me to throw out some strong clear glass qualities:
- barium for clarity, modifier
- calcium for economy
- strontium to replace some calcium
- lithium for workability
- erbium for color removal
- alumina for strength/durability (hydrate, not feldspar due to concerns of contaminants)
- nitrate for melt
- potassium for clarity
- keep alkali below 18%, modifiers at above 8%, silica around 70%
- lithium between 2-5%
- antimony to fine the melt
- no borax...Pete insists this with barium is a big no-no. Glasma would disagree and so would Cristalica. So I might add some back in case the glass did not melt well.

I'll work it up in the calculator for 100 lbs and see what it gives for a 96LEC batch.



The silica is a little high but may be fine. Alkali is below 18% at 17.73%. Modifiers include calcium, barium, strontium and zinc...these add up to 8.28%. Nice potassium at 3.04%. Lithium is about .3%. Alumina at 1.5%. The calculator does not make an allowance for erbium as it is added in minute amounts...who could afford any more than that?

Other Expansion estimates a 96.3 LEC which looks pretty good compared to some other formulas I've looked at.

Will it melt? I dunno but it's no bargain! Nearly $0.68/lb before shipping!!! Plus you get to mix it yourself.
Bulk buying power allows the batch companies to make money. Most of us get the pottery store markup.

Hopefully that was a nice thought exercise for you to see how a priority set can be used to establish a first-try batch recipe.

[vitroholic]

When I was first introduced to glass in the early 80s, my teacher had formulated the batch. It worked fine for what we were doing. He eventually got hold of the penland formula and switched to that for the optical qualities.
It was good experience to go through the batching process, going around and getting the materials, (I think the sodium nitrate came from a farm supply store) weighing everything out, mixing and shoveling it into paper sacks to throw in the furnace. I saw the teacher's thinking develop from using coarse materials to buying finer powders, and getting really nice optical qualities for the trouble.
I still think back to that original formula, though. The simplicity of a formula with less than eight ingredients. I recall it was very receptive to irridizing as well.
What I've been doing lately isn't all that optically demanding, and with all the hassle around sourcing batch or cullet, I think more about doing my own batch.
This is a roundabout way of saying thanks for posting this simple recipe that someone like me could use as a starting point.  I don't expect to take it and be in production with it tomorrow. it'll take some refining and experimentation to get it right.
  Your idea of starting a forum for open source information is laudable. 
I recall talking to a glassblower at an art fair once and asking if I could come see his studio. He said I could see the studio, but wouldn't be able to watch him work. The way he saw it, he'd spent a lot of time and money learning his techniques and he wasn't going to just give them away.
My first thought was what an ass the guy was. To begin with, I wasn't going to see some shortcut watching him and be in competition with him the next day, stealing his hard won technique. further, he stood on the shoulders of giants, like all the rest of us. His skill, which was considerable, didn't appear of his own virtue alone. I wasn't so much looking for a free class as much as some inspiration from seeing how far his work and learning had taken him.
That said, I'm not going to burn bridges by mentioning the glasshole by name.

 

[Administrator]

Thanks for the post. I was surprised to get one so soon after starting the forum. Seems like there is space online for another furnace glass option. I took the time to read through the Craftweb archives post by post. Lots of techniques revealed and color tricks shared. I'm going to try and help those resurface for myself and the glass community to more easily find.

It's what we do with these things that matter. Got to keep innovating and trying new things.

Lots of jerks out there. I've met very few people willing to bring others along and foster their growth. Sounds like your instructor was such a person.    I guess this forum is my way of trying to do so. That and I just love glass. Great username!

[vitroholic]

I can never be sure I'm not one of those jerks sometimes, if you know what I mean...
Yes, my teacher was very good at teaching  beyond mere glassblowing, which he readily admitted wasn't his strong suit. He was mostly self taught after getting a grad degree in ceramics.
One of the things I most cherish was that during my second or third semester with the class, the teacher decided he wanted a whole new studio, so we spent the entire semester tearing out all the furnaces and building all new ones from scratch. Tank furnaces, glory holes, annealers, everything. What I learned that semester propelled me further to becoming a glassblower than the other four or five semesters I was there. It allowed me to go out on my own and make a couple of really Fu***ed up furnaces with scrounged materials (vacuum machine for a blower, anyone?) and learn how to make one I could really use.
good times!

[Administrator]

I think I know. I live in an area with very few glass artists. It was different when I lived in San Diego and worked in a few studios that rented time. You ran into glass artists of all stripes and some of that rubs off on you. We have to be influenced by the people we respect. I've asked people for help or to train with them only to be ignored or just flat told no. I still have the first piece I ever made while being literally walked through the studio by a dear friend. A small paperweight that means more and more to me as time goes by. I'm not a full time glass artist and that could be a big difference in my thinking.

I trained at Palomar college which had two consecutive teachers who started as ceramic artists. The glass just took hold of them. The training was team style or, at least, gaffer w/ assistant. The teacher's approach was jarring to me as a an older student in my 30s. Sort of felt like a drill sergeant barking out orders and scolding mistakes. For me to put up with it for a couple semesters showed my desire to learn. But a lot of gaffers are this way...perhaps necessarily so. Shouting, dressing down, demanding perfection...I know a couple that split up, in part, over this dynamic being incompatible with a marriage outside the shop. Ouch! Funny thing...rather than even suggesting to the artist that their approach was too harsh, the situation convinced her that friends and family should never be gaffers' assistants.    I love to watch the teams demo at Corning. It may have taken some yelling to get the point of wordless conversation between gaffer and assistant, but I have the feeling that the better the gaffer is, the more easily they make it for the assistant to do their job. I'm at my best when I'm super chilled out while blowing...It's just glass. Is my mantra.

I've worked solo almost exclusively. I've built my own equipment and love the sense of "power" I feel in knowing exactly how something was made. Rebuilding, maintaining, upgrading becomes so much more accessible. I'd love to bring along an assistant but it would be difficult in my current situation. I live far outside the town and there just are not many glass artists around here. I see people at my glass shows and they suggest they want to learn but then you never here from them. I welcome it. I've got a lot to share so here I am.