_Next PageLately I've been getting a lot of e-mail about copper foil. Mainly it's about it un-sticking or not getting it on evenly, etc. I'm going to list out common mistakes and problems people make when copper foiling.
COPPER FOIL PROBLEM #1 - The foil doesn't stick
This is the main question, why doesn't my foil stick to the glass.
Here are a bunch of questions you have to ask yourself:
Is your glass ground?
It isn't absolutely necessary to grind your glass. They didn't have grinders when Tiffany was doing stained glass; but then again, his foil was a bit thicker (there was less of a chance of cut fingers). Grinding the glass makes the glass neater, and gives you a better finish. Grinding also prevents cuts; cuts cause blood, making the foil not stick.
But grinding does do something else for you; it gives the foil an extra surface to "bite" into. When the glass is UN-ground, the edges are smooth (and still quite sharp by the way), the foil may slide off edge when you solder it; heat can cause the foil to slip off. It's like putting sand down on an icy walkway, it gives you a better chance of not slipping on your tushy. This is a G rated sight, you know, I'm not saying the word you might be thinking…
So basically grinding the glass will give the foil a better chance for adhesion. It will prevent your precious fingers from draining. And it will make your finished project look more professional.
Is your glass clean?
This is a valid question. The glass should be squeaky clean. There shouldn't be any grinder scum, fingerprints, or glass cutter oils on it. After you grind the piece, always wash it off. Simply wiping the ground glass with a damp rag is NOT enough. The ground edges are now rough and they may catch all of the residue.
Wash the glass off under running water. I use hot water, (when I dry the glass, it will dry faster, because it is now warm). Hot water will also prevent condensation from forming on the glass. For small pieces, just run it under the water, no rubbing required. For large pieces lightly rub the edges with your finger to remove the glass grit (while the water is running).
Is your glass dry?
Dry all of your pieces with an old, clean towel. Dry the faces of the glass and the edges. I've always stated with the faces of the glass, because this is where the large water droplets are. If you ground your glass like a good little person, the edges should appear frosty in color. This will let you know that it is dry. Be careful to watch out for air bubbles in the glass. When you cut a bubble in half it forms a pocket. The pocket can hold water, which will either come out as you dry, or while your soldering. Rubbing it will help to remove some of the water. A hair dryer may be your only hope.
After I dry the glass with a towel, and I'm ready to foil, I usually blow on the glass. Blowing will help remove some of the moisture. Don't spit on the glass when you blow on it, foil doesn't stick to spit. When you're foiling, your thumb may be damp, and will cause a damp spot on the glass. And of course, the foil won't stick to that, so just keep an eye on the color of the edge. It should be white in color, not dark.
Is your glass bumpy?
Your glass may be too bumpy. And by that, I mean the top surface not the edge. Ripple, granite, and the like, can be difficult to foil. As you squish down the foil, the bottom will be tight, but the top won't. The only way to foil the bumpy part neatly is to rub the foil down into each "hill", its time consuming work, but worth it.
What could happen later if you don't take the time now for proper foiling, is this:
Is your glass too thick?
GOOD - You're using 3/16" foil. Your also using Spectrum glass, this combination works.
BAD - You're using 3/16" foil. You're using Wissmach, Armstrong, or some other thick glass, this doesn't work.
Why doesn't it work? On normally sized glass (usually a little under an 1/8"), you can get a descent amount of foil on the glass edge. 3/16" will give you roughly 1/32" or so on either side. Armstrong has some thick glass, the same sized foil, may not be wide enough for that glass. The overlap may only be 1/64" or less, which won't allow the foil to really stick onto the glass. Worse, however, the foil will lift away when you solder. And if it doesn't, that area will be a weak spot afterwards, and it will bend there.
Use a thicker foil for thicker glass. Instead of 3/16" use 7/32" for that glass. Trim the excess away if needed (carefully with a razor blade). If the glass is an inside piece, it won't make as much as a difference. However that piece of glass won't have the same solder thickness and it may stick out.
Do you have anything on your hands?
You're foiling right now (well not right now, right now you're reading this, but let's make believe we are, ok?) What is the state of your hands? Are they dry? Do they have lotion on them? Are they dirty, dusty, greasy?
Your hands should be dry, not "write your name in your hand with a dull stick" dry, not moist or greasy. The moisture or dirt from your hands will transfer to the foil when you go to apply it. You don't want this. When you are taught to do stained glass, your teacher probably told you not to ever touch the sticky part of the foil. I'm sorry, this is impossible to do for me. I have to touch it somewhat. Usually it's just my thumb, it's used to pinch the foil, and guide it on.
Did you rub down the foil thoroughly?
After applying the foil, you have to pinch it down so it's evenly on the glass. But you also have to rub the foil down with a fid or some other kind of stick. This is the real secret of successful foiling. It has to be rubbed down. You can use a sharpened dowel like I have. You can buy commercial ones, made of plastic. You can spend anywhere from $1.00 to $20.00 for a fid. I spent about a dollar or two for a few dowels. One dowel will yield about 4-6 fids. Each fid can be re-sharpened about 6-8 times. This is the way to go.
Every piece should be rubbed down. The small pieces are also included. If you can't rub it down (and it has to be pretty darn small to impress me), then press it down on a hard block of something. I use a piece of thick tempered glass. Press the glass down with your thumb, or the back of the fid. I also push down all the corners at this point. Push down the corners now will allow the piece to sit flat, not get in the way of the soldering iron, and prevent small stab wounds.
How tight should the glass be? Let's put it this way, after I foil something, you would need a razor blade on all three sides to remove it.
How old is your foil?
Sealed in the bag copper foil only has a shelf life of about 1-2 years. Though most bags have a hole in it, so seal your foil in a tight box or bag. The main killer for foil is moisture. If you can, put a pack of silica gel in with the foil. Silica gel, by the way, are those Do Not Eat packages you get when you buy electronics. You can also get it in a powdered form in a craft store or a florist. It's used to dry flowers.
MY FOIL KEEPS LIFTING UP WHEN I'M SOLDERING
Here's the checklist:
Your soldering iron is too hot
The glue on foil is pretty good. But it has a hard time resisting heat. Basically, you want to flux and solder. If you keep going over the same line over and over and over, it will look bad, and the foil will lift.
You'll see the foil lift mainly along the edges when you solder a box edge. The heat is in the solder, so be careful when you run a bead on the edge. Don't pull a bead on the edge like you would on a normal seam. Instead, flux, then drop some solder down on the edge. Then let it cool, and do the next one (no extra flux is required), usually it's best to drop it down in random places on that edge. If the foil lifts as you do that, push it back down. Use the iron or a metal object, to push it down while it's still hot. You may get lucky and be able to keep it, but you may have to tear off the foil and replace it. Which can be very difficult to do with a box edge.
If it lifts in the middle of a panel, you can get hide it a lot better. Just poke it down with your iron and cover it with solder.
Your not moving your iron fast enough
This coincides with too much heat. Keep your iron moving, don't lag for too long, or go over the same area too much. I never timed how long I've been over one area, but it isn't very long.
Your using too much flux
You may be saturating the are with too much flux. And in turn the flux may be dissolving the glue on the foil. How do you fix it next time? Don't use that much flux.
You have a bad foiling job
Hopefully the first part of this FAQ would help you here.
Your rubbing to hard when you wash it off
Well, don't rub hard. When you scrub your project or polish it, be careful around the edges. Even the best foiled projects will be ruined by this. The only time this could be prevented is if you did one of the following things:
MY FOIL TORE! NOW WHAT?
Re-foil it if it tore by accident. If it tore because it caught on the soldering tip, it's harder to fix. Don't rip it off if you can help it. Instead tuck it in carefully, and keep beading. A rip can be quite obvious, try not to let it happen.
What causes a rip? Usually a crusty old soldering iron can cause the foil to tear. As you drag the iron across the seam, you tend to touch the foil. Which is ok, unless there's a burr on the tip itself. Or it might tear if you left that sharp pointy corner thing on the piece of foiled glass.
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Started on 11-28-98