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.