Devardi Glass With Premix Torch?
 

I am pretty new and have a premix torch with propane and oxygen (I already had this torch and will get a surface mix when I can afford it).

Anyway, all was well with the COE 104 glass I bought off ebay, etc. I used both transparent and some opaque with no problems with color whatsoever.

However, I ordered some white and yellow Devardi glass. My torch discolors it. At best, it makes the white turn to a very off white. At worst, it turns the yellow to a dull, ugly blue and the white to very dark grey.

I have tried adjusting my flame every which way. I've tried very low heat and higher heat. Also, I've tried using the flame near the tip and further out. Some adjustments work better than others. It seems like the adjustments on lower heat and with some orange in the flame (lower oxygen) work best, but none produce unchanged color in the yellow and white beads.

Am I still doing something wrong or is it impossible to make a premix torch work with Devardi glass? Should I just forget using the Devardi glass until I get a surface mix torch?

You're kind of in the minority here for even having tried soft glass with a premix torch, I think. Whites are going to be the worst for this mix, Devardi or not.

I'd try using a very small flame, and working out past the visible flame

If your torch uses national style tips you may be able to switch to a surface mix tip.

I have a surface mix torch, but I have never had very good luck with Devardi Glass. Could just be me though.