White Spots on Black Patina (Copper Foil)

by Chuck Bosshart
(Two Harbors Mn.)

Sue, First of all I would like to thank you for creating this web site, and taking the time to help all of us out here in learning this wonderful stained glass hobby.

I have been having a problem with my finished stained glass projects after a few months the solder lines start to get white spots all over them.

I read you tutorial on how to wash and patina the glass projects and found that I was doing it wrong. I have only used black patina so far and I have been using Dish detergent to scrub and clean my soldered project (with a soft brush and sponge) I then dry it, then I apply the patina, Dab it dry then apply ( Clarity ) Stained Glass Finishing Compound let it dry and buff it to a shine.

I'm thinking that maybe the dish detergent isen't getting all the flux and oxidation off the solder lines? I do have a product called CJ's Flux Remover but have never tried it, I thought the dish detergent was doing a good job, but after reading your instructions it must not be. What do you think?

Also can you give me any tips how I can repair the projects that I already have compleated that have these nasty white spots on them. Is there some way I can clean them off, repaitina them and then replolish?

I really appreciate you taking the time and your experience to help us all do a little better job with our hobby's. Thank you Chuck Bosshart

Answer

Hi Chuck,

I'll start off with how to repair the ones with spots. Clean the patina off with very fine steel wool or better yet use bronze wool, which can be obtained from many stained glass suppliers. Just rub down the solder seams with the steel/bronze wool and the patina will come off.

Once it's off, follow my patina instructions from start to finish. When yoy wash it, make sure you scrub well, especially along the edges of the solder seams. Use a toothbrush as well as the scrub pad.

The white spots are quite often caused by humidity, chemical vapors (open flux bottles in the same room), and I have found running my kerosene heater (perhaps the fumes) in a room with stained glass causes the white grunge.

What I see in your picture looks exactly like my glass that was in that type of enviroment until I changed my method of applying patina, as I describe in my tutorial. I have not see any evidence of it since that time. However, I do make sure that all chemical bottles are tightly closed, and I don't run a kero heater any more. But...it still gets humid in the summer (and, unfortunately, I can't change that!).

Make sure you wax well. A second coat certainly wouldn't hurt. Use a tooth brush to get it out from under the edges of the solder seams, and out of corners.

One other comment...I have found that Mothers Wax does a super job and costs far less than any wax packaged specifically for stained glass.

Lastly...you're welcome!

Let me know how your patina looks from now on.

Sue