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I just got done doing a large box. It was a cremation urn demo for military funerals. Spectrum glass The old red opal, blue opal and the white. It was all fused together and then I copper foil it then solder. Clean flux off really good strong solution lots of scrubbing. I than used the Novacan Copper Patina putting it on with a cotton ball. Patina went on great, nice finish to the solder. Rinsed, found I have stains where the patina dripped on the fused glass. Never had this happen on stained glass projects. Its like it ate the gloss of the fused glass where it dripped. I have tried clr to see if it would remove the stains. No way. Also you can see an oil haze on the white and blue probably on the red but you can't see it. Pictures don't show the streaks.
Any idea why this happen and is there anything that could remove the stains.

Many patinas contain acids. Acid will "etch" fused glass, especially if you've used SuperSpray on it.

Nothing I know of will fix this except refiring the glass.

Sorry for the bad news.

Geri

There is a "stain remover" (don't remember the name) that *should* remove the staining. We had this problem with iridized glass after applying the patina. Aslo, I would suggest using a cloth only dampened with the patina and rapidly lightly rubbing the solder. It takes only a little patina to react with the solder. - Barbara

We've had this happen on areas that were silverstained.... reaction with the metal in/on the glass I suppose. It's not a problem on a window because it doesn't show with transmitted light, but I imagine it was a bit of an eyesore on the cremains box. I don't know of anything that will get rid of it short of blasting it off which is hardly a suitable solution in your case. Sorry.

I also think that the best you can hope for from this, is prevention next time. When I have to do some patination near glass that is prone to this, I use a variant of Barbaras technique, a Q tip. Same idea, pinpoint application. This is a long shot solution, and I don't think it will do it for you, but sometimes when a stain is permanent, you can just stain the whole thing and have it come out looking better. Woodworkers do it when oil contaminates certain finishes, and I have done it a time or two with success. Of course I've tried it other times and scrapped the whole project. Just a thought.

Novacan makes a product called The Stain Remover That Really Works. I've used this on regular s.g. where the glass has been hazed by patina and it will take it all off and bring it back to a nice shine. I haven't tried it on glass that's been fired or had an anti-divit spray applied to it but it's cheap enough to give it a shot. I just dab it on with a q-tip, changing it out when it gets dirty. Then wash it good and hopefully, everything on your project will be fine.

I recently learned, the hard way, from experience, that patina will damage and/or remove low-fire enamels.

I was using Fusemaster transparents but I am told it will happen to others as well.

The Hobbyist.....................................Jim