After applying patina to a project, I have been finding patches of copper foil showing through. At first I thought I had not covered the entire piece with solder, but I have been paying close attention since noticing this problem. The piece is definitely soldered. I have tried making sure the piece is thoroughly cleaned and that there is no flux accidentally coming into contact with the piece after cleaning. After applying patina is when the copper starts coming through again. It's not an immediate reaction because I don't see it changing as I apply the patina. I am wondering if my storage of all my chemicals may be the problem. I have not found warnings on the bottles, but I wonder if extreme heat or cold would cause chemical breakdowns or reactions. These bottles of chemicals are stored in a room off the house that is not particularly well insulated and is not heated. It gets hot in the summer and cold in the winter. They've been in this room for about 3 yrs now. I've done 5 or 6 projects in the last couple of months and have had a problem with all of them. I have only used black patina on them. Before June I had no problems and was less careful than I have been lately in cleaning them.
Hopefully you can answer some of this. My stained glass store owners could not tell me anything about the possibility of chemical problems. I have no other ideas. Thanks. I look forward to hearing from you.Answer
Would you please send me pictures of before and after applying patina. I need to see what's going on. Also tell me what kind of flux you're using and what brand of patina. Is your patina old or new, and do you dip your applicator right in the bottle, or do you pour a small amount into a container and dispose of the remainder when you're done?
You can send the pictures and answers through my "Contact Me" page.
It doesn't make any sense how the solder could disappear in spots after you use patina.
My chemicals are in a room that is not heated or cooled. The water in my grinders actually freezes in the winter.
I'm thinking that you're not seeing copper foil but it's the black patina that has a copper look to it in spots. I've seen black patina that does just that especially if it has been contaminated by dipping into the bottle each time it's used rather than pouring out a small amount and disposing of the rest when you're done using it.
Are you following the directions on my web site for cleaning and applying patina?
I'll be waiting to get your pictures and answers,