Neil - I think the beads are between 53 & 75 microns, its very fine powder.
John, it's not from an MSDS sheet, it's just their table that has the typical composition, that was all they had.
I'm not necessarily going for translucency at low temperature, but I do want a strong and vitreous body, and I would like it to be as white/light as possible. My kiln doesn't quite get to 1100C (and thats a struggle for it, I can't really push it past cone 03) which is why I got interested in this project initially.
Unfortunately, none of the commercial earthenware clays available to us here in Melbourne are vitreous and they are fairly weak (they chip really easily) so I normally add frit to my earthenware bodies to lower the MP and produce a much stronger, vitreous body. The only problem with that is that the frits here are quite expensive, which is why I was interested in developing a recipe with the glass powder.
There are a few research papers where people have trialled cullet with good results (in industry rather than for artistic purposes), and I figure once I know what sorts of issues I'm going to encounter if the composition varies (eg, if the alumina decreases or increases, if the soda decreases or increases, etc - how will I tell, what will give me an idea of what's changed and I think thats only going to come from understanding the chemistry really well), then I can adjust the recipe. This is why I asked for title of good textbooks to chase up, so I can have an understanding of what the various components will do in a clay body, so if something goes wrong I have at least an idea where to start to adjust.
As it stands now the body is good, except for the fact that it seems to be absorbing the glaze. The translucency is the added bonus.
I'm aware that for those who have access to kilns that can reach stoneware temps it must seem like such a waste of time and effort, but I've had a few emails from people in the same situation as me that are watching with keen interest. And if I CAN work this out, in the long run it will mean that I'll save money on firing, plus I will have the added benefit of the expanded colour palette.
It may prove to be fruitless eventually, but for now I keep making steps forward so I'll continue on. It would just be easier if there were others that had tried this and succeeded on a large scale that I could get guidance from, and without a ceramics chemistry training I feel like I'm walking forwards blindfolded. If I can succeed, I think the benefits will be very well worth the effort.