Your Copper Foil Isn’t Sticking to Your Stained Glass?

If your copper foil isn’t sticking to your stained glass, or it’s lifting up when you solder, you’re in luck!

Why? Because while it’s an annoying problem to have, it has some pretty simple solutions.

copper foil fid stained glass tools Mountain Woman Products

Ya Got Some Low Quality Copper Foil Tape There, Bud

I know, I know. I feel ya! The more money you save on other stuff, the more money you have to spend on allllll the prettttttty glaaaaaass!

But, don’t go crazy no name cheap on your foil. Glass Supply Stores consistently carry particular brand names of foil for a reason: they consistently work.

Stick with (pun absolutely intended) big names like Edco and you won’t be disappointed.

Find my favorite foils & sizes on My Favorite Tools & Supplies page.

Your Foil is Old or Improperly Stored

Unlike your crazy old Aunt Ida (the one who wears every bracelet she owns at the same time, a pink track suit, always has lipstick on her teeth, and retired to Florida with her fifteen cats because “I need the heat for my bones” (but really it’s the margaritas), copper foil tape doesn’t appreciate sustained heat and humidity.

Leave the pool for Aunt Ida.

If your foil is not in a climate controlled room (think garage, shed, basement), it’s smart to store it in a zip top bag or airtight container.

In fact, why not just store it that way regardless of what room you keep it in? It makes it easy to organize & label your different sizes & backings, and will keep your rolls from unraveling too.

Did you inherit or purchase a bunch of used stained glass supplies?

Your foil could either be old, or have been laying about basking in the humid, dewy goodness of someone’s basement for the last twenty years.

Try with a new roll.

If you’re having the same problem, it’s probably not a foil problem, it’s probably a you problem. Don’t worry. We’ll fix it.

Your Glass Is Dirty

Oil from your cutter, grinder dust, and even people grease will inhibit the adhesive properties of your foil.

Some artists like to use alcohol pads to clean their glass, but I’ve found that nothing beats good ol’ fashioned dish soap & water. The side benefit of the dish soap & water situation is your hands get squeaky clean at the same time as your glass.

Don’t forget to dry your glass & hands thoroughly before foiling.

Foil & Glass are Cold

If your copper foil isn’t sticking to your glass, it’s cuz it’s cold and lonely.

Glass & foil both like to be toasty when they get together. Your glass should be warm (doesn’t have to be hot, just people temperature) & your foil, the same.

The safest and easiest way to keep your foil & glass warm & happy is to foil in the house. But…

If you’re working in a chilly room, you can place your glass & your foil on a heating pad or seedling warming pad to warm them up. Be sure to keep the pad on a low setting so you don’t melt out your foil adhesive.

Aaaaand, my electrician dad says…”Set your glass on & remove it from the pad gently! You don’t want to be cutting any wires. Zap!”. He makes a good point (get it?, get it?). We should probably listen to him.

In my old, drafty studio, I set my glass vertically in front of a space heater to warm it up a bit. Keep it about a foot away from the heater & don’t leave it there for more than a few minutes so you don’t overheat the heater (another dad tip).

Note: Do these at your own risk. And if you don’t listen to dad, then that’s your own dumb fault. ๐Ÿ™‚

You’re Not Burnishing Your Copper Foil Well

After you’re done grinding, be sure to clean your glass thoroughly. I mean clean, cleanditty, clean clean. No oil from your cutter. No people grease.

Once you’ve wrapped your foil around your glass piece, you need to burnish it. Well.

You don’t need to go all Lady Macbeth level scrubby with it, but be sure there are no air bubbles to be found. It’s a pressure akin to rubbing a scratch off lottery ticket.

Too Much Heat While Soldering

As you’re likely aware by this point, copper foil tape doesn’t cling to your glass with sheer will power and determination. It’s the adhesive that keeps it there.

Unfortunately, adhesive melts at sustained high temperatures.

So, if you’re holding your iron in one area for too long, or you’re continuously going over a portion of your bead to fix it, you’re overheating the glue & thus causing it to leak out from under the foil.

This. This is too long ๐Ÿ™‚

Now you have yourself some air space under it.

Guess where your flux wants to go? Right on up under there!

Let your solder and the foil under it cool before you go back to fix problem spots.

If your copper foil is peeling off the glass all over the freakin’ place while you solder, and you’ve already addressed the foil quality, storage, cleaning, & burnishing issues, your iron temp may be too hot for the speed you’re working at. Turn it down a bit.

Tinning Only

One of the biggest Eeeeeeeeeeeaaaaaacks! I see in stained glass is not edge beading a finished project. Tinning is simply laying a super thin coat of solder on your copper foil. It’s like priming before you paint, which is good, buuuuut…

Tinning does absolutely nothing for the structural integrity of your piece.

If you’re only tinning, and not building rounded, domed solder lines & edge beads, it’s kind of like painting a piece of Scotch tape & hoping it will hold a bunch of glass together.

Because copper foil tape is floppy & flexible, even small movements, like picking up or waxing your “only tinned” project can result in your foil separating from the glass.

Tinning only = Crash! Boom! *crying* Not good.

What happens if you leave a finished piece with lifted foil?

Smash! Crash! Bam!

Well, not necessarily, but it can.

It’s about structural integrity. Your foil creates the base for your solder. And your solder is the framework of your art. Lifted foil, and thus, lifted solder creates a weakened spot in your piece.

Will it fall apart in the next ten minutes? Probably not. But, depending on the location of the lift & the weight of the piece (like near a jump ring), it sure could.

It’s of particular concern if it’s a larger or heavier piece. Regardless of size, you want to make quality stained glass art, right? And, the last thing you want is to put all that effort, time, and love into your work only to have it fall apart.

So, foil right my friend. Keep your art strong & beautiful right on through its golden years. Like Aunt Ida.

Peace, Love, & Stained Glass,


P.S. – Save yourself some time, money, and frustration. Learn to make stained glass without trying to figure it all out on your own!

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2 thoughts on “Your Copper Foil Isn’t Sticking to Your Stained Glass?”

  1. Hi
    Thank you for your blogs… The descriptions are clear to understand for a beginner.
    I appreciated you sharing your knowledge and experience.


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