Copper Foil Lifting

by Christa Leach
(Gauteng, South Africa)


I would like to know if copper foil can become old and not be suitable for glasswork? I bought some foil from our local craft shop that specialises in Stained Glass products. I find that this particular roll I am busy will now, keeps on lifting when I start to solder. I do clean my glass properly with surgical spirits and I take special care with burnishing my pieces, yet the foil keeps on lifting. I also noticed that as soon as I start soldering, it looks like little bubbles appearing on the foil, causing the soldering to look ghastly!!


What am I doing wrong?

Answer
I don't think you're doing anything wrong. You most likely have a defective roll of foil. Take it back and get another roll. As with any product, foil can be defective.

And yes, it could be old. If it has been exposed to heat, like sitting in the sun for several years, it looses it's ability to stick tight.

Comments for Copper Foil Lifting

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Oct 24, 2010
copper foil lifting
by: Janice

I have had some foil rolls for about 4 years, kept in a drawer in a cool place (my studio is in finished basement). The color seems darker on the surface, as though the copper needs polishing. Sometimes my foil lifts, but I suspect I am not cleaning the glass carefully enough. That usually happens when I am in a hurry. I'm just glad that the age (of the foil) is not the problem - I was concerned about that.

Reply from Sue

I'm sorry that I didn't say something about the age of foil. Yes old foil can lose it's ability to adhere properly. However, it's a hit and miss situation and I believe it depends on how old it is and how it is stored before you buy it as well as how long you've had it. Also, exposure to heat will cause the adhesive to deteriorate faster than if it's stored in a cool place. I've heard of people storing their foil in the refrigerator although I've never tried it myself.

When you apply the foil, the glass must be free of glass dust from the grinder and oil from your hands. The easiest way to do that is to wipe the edges of the glass with some alcohol on a paper towel. It only takes seconds to do it and the alcohol not only cleans the glass, but it seems to make the foil stick better (maybe that's because the glass is clean!).

Equally important is burnishing. The foil has to be tight against the glass. If it isn't, flux will get under the foil and cause it to lift. If flux doesn't get under it, water will when you wash it.

By the way, the darker color of your foil is oxidation. It happens over time from exposure to air, and air can get to it, even in it's original packaging. It's nothing to worry about since your flux will take care of it when you solder.

Oct 23, 2010
Foil
by: Anonymous

I also have that problem.. I go through alot of foil and purchase it 6 rolls at a time. I will be soldering around my pieces and it seems to do well and then not. Hit and miss. I have opened new packages thinking that it is defective and it happens again. It is very frustrating for sure. I have found that it will burnish down even after foiling tho. Maybe it is the brand that I have been ordering. It is Brighton foil silver back and black back.

Reply from Sue
Try Edco Foil. As far as I'm concerned, it's the best there is. Do a Google search for it. Quite a few places sell it, and several places have it on sale right now.

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