How to Repair Stained Glass

Being able to repair stained glass is a good thing to know. You may say to yourself "Ida, (providing your name happens to be Ida), I don't ever plan to fix someone's project, why are you making me learn?" Well Ida, it's like this; you may never have to repair someone else's project, but you may have to repair your own project. Whether it's going to be sold, or whatever, it's a good thing to know, regardless.

Without pictures it may be hard to visualize, but I'll give it a shot. I only do copper foil work; I have no idea how to fix came. Anyhow, here are the general steps:

By the way, we're going to make believe we're fixing a small window. The broken piece will be in the center surrounded on 3 sides with an outside edge. For arguments sake, the piece is pink opalescent made by Wissmach. The window is a few years old, and is a bit grimy. This window itself is not a restoration, just a basic window with 1 piece broken.

STEPS:

Clean off your panel; use a good glass cleaner. If you have to, clean it off in the sink with soap and water. Be careful of the sharp edges. I often clean everything off with denatured alcohol.
Make a copy of the piece your going to fix. If the project is small, photocopying works really well. Most of the time you'll need to do a rubbing of the piece (like a grave rubbing). Get the flat edge of a pencil (sharpened, the yellow part isn't very effective), and using a piece of paper, rub the area where the piece is broken. Another method is to trace the solder joints using a felt tip marker, and clear plastic acetate (you can get acetate at an art supply store). I've used plastic that transparencies are made of.
Now that you have an accurate outline of the area, you're ready for the next step. Find your glass replacement. Wissmach pink opalescent should be easy enough to find. The window is basic, and it may not depend on a swirl; of course it may. If it's Spectrum's Baroque glass, you'll need to find a good swirl replacement. In other words, do your best to match the remaining glass.
Using your pattern and the broken glass, find the part of the new piece of glass your going to use. If the piece you're replacing isn't that important (grain wise), then place the pattern outline somewhere near the edge of the replacement glass. Basically set it up as if you were going to cut it out.
Now the fun part... Removing the old glass. This part can be tricky. So I'll divide it up into sections:
- The glass is cracked only: If the glass is still whole, use this method: score the surface of the glass (the broken piece). Score it about every 1/4" to 1/2". Criss-cross it, do it diagonally, in both directions. Next tap the back of the glass with the ball end of the glass cutter. Keep tapping until all the glass is cracked (ran) through. Then pop out the bits of glass, using pliers, (needle nose or grozing). Remove what you can; don't force anything. More about removing the other chunks will come later.
- The glass is cracked badly, parts are missing: Remove what you can by grabbing the end of the glass with your pliers. Wiggle them until they are removed (like a loose tooth). Again, don't force it.
Sweep up the area. Right now there should be a bunch of sharp glass crumbs on your bench.
Plug in your soldering iron. Coat the solder lines with flux. Then heat the fluxed joints so the solder melts. This may be tricky; there may be oxidation on it. This is especially true if the solder was patinaed. The patina tends to form a shell over the metal. Remove as much of the bead as you can. Put the excess solder somewhere. I try to reuse that stuff for filler.
With the excess solder gone, the remaining glass (if any), should be able to be removed. It may be tough to remove some of it. There could be a deep corner that the glass is wedged into. Do whatever you can to remove it; use grozing pliers and groze it out if you have to. But be sure not to flex the piece or you may break more of the window.
Sweep up the area again.
Next you want to remove the extra foil. I add more flux, then carefully wedge the soldering tip between the old foil and the adjoining piece. Be very careful not to tear the foil off of the other pieces. Once you get the iron in there, it helps if you rock it a little, like jiggling a key. Break the foil off, so there's a tab. Using a needle nose pliers, hold the tab, and place the iron against the edge below the foil you're holding. Like de-skinning a whale, you hold the skin while cutting it off; sorry for the graphic description but it's good to visualize. If you're having a problem visualizing someone peeling the skin off of the free Willie whale (personally I'm not), pretend it's the Carvel Fudgy Whale, as you peel off that yummy chocolate skin.
Carefully and steadily pull on the foil while you slowly push the iron in. Rocking helps alot. It allows the iron to walk over the seam because the iron doesn't slide very well. Keep doing this until all the old solder and foil is removed. Other people use soda can strips to separate the foil from the rest of the project (I never tried it). Finish off the area by removing and solder spikes, blobs, etc.
Sweep up the area again. When repairing, there's always a mess.
By now the area that your working on should be free of old foil, glass, and solder. Make sure that all sides still have foil on it and that the foil that is there, isn't loose. If the foil is loose, remove it and replace it. Loose foil can be bad later on; it can get scrunched or weaken the window.
Unplug your soldering iron if you're slow at foiling and cutting (it'll save on wear and tear on your iron).
You may need to re-foil the area. It's difficult, although since this particular project has an open face on end, it's a little easier to foil. Use whatever trick works for you. Only instead of folding the edges down, rub the edges first. Then slowly bend the sides down, while rubbing. This way you know there aren't any gaps under the foil.
Good, now that the area has new foil (if it needed it), onward onto the next step. Set up your area for cutting the glass. And, as always, make sure there isn't any solder, glass, foil, flux, etc. are on your bench.
Line up your new glass under the project the way you want it. Then trace the inside lines onto the glass (like tracing around your hand).
At this point, you should have the 3 sides traced onto the glass. You will now get to use the pattern you made before you destroyed the piece you were working on. Trace the missing part of the pattern onto the glass. This pattern becomes very important if you have more than one piece that your replacing. Removing too many pieces leaves gaps where solder joints used to be. When using the rubbing you made, split the difference for the pattern shape.
Cut your glass as usual and check for fit. Grind to fit if needed; lightly grinding it doesn't hurt either. Make sure to leave a tiny gap for the new foil to fit so when you do grind the glass, it falls into place and isn't tightly shoved in there. Otherwise the foil may tear, and you'll have to remove the foil and start again.
Wash off the new piece and foil. Also clean off the area where the new piece is going to go (just to wipe off the grinder scum).
Place the piece where it's going; you may need to match the height of the glass to the rest of the windows. Any beads, or wire on the back will alter the height of the new piece. Since the new piece will be level on the table, I've used foam sheets (cut to fit), thin glass, and often masking tape. In this case we'll use masking tape. Providing the area is clean, tape the piece in place on the back. Place the tape along the seam (not across it). This will catch any solder dripping through. This method is great anytime you're trying to fill a gap that's in the air (like a lamp).
Solder as you normally would, matching the bead height, along with any decorative soldering. Flip the window over; remove the tape and solder. Replace any moved reinforcements and hooks. If it was a box, replace the chain or hinges as needed.
Clean as normal.
If the project was patinaed, say copper, make the new joints that color. You have to decide if you want to match the existing patina. It's easier to just polish the old to look like the new. Though once I mixed a little copper with a little black (though this was kind of stupid thinking about it now because mixing acids isn't terribly smart).
Polish, wax, and your done.

Repairing a project can take almost as long as building it. People wonder why a small crack on the bottom half of a box on the hinge side would be so expensive to fix. The charge you give them may be more than the whole thing is worth. Why would it be so expensive?

In order to fix that part of the box, you would have to remove the lid, the chain, and the old hinges just to get to the broken part of the glass out. And then you have to repair it (providing you have the color), and put all that stuff back. Later you might find out that the lid isn't square, and now you have to readjust the repair to match up with the lid. So a $20 box may cost $15 to $30 to repair. It may be cheaper to make them a new box and faster too.

Another thing to consider is the glass type when you take on a repair. Be sure to tell your customer that certain glass types may not match exactly. If you get a box that's made of baroque (the type with the flowing sides, connecting from top to bottom), you'll never match the swirl, and it will always stick out. Maybe you can make a flower or something on that side.

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Last modified June 10, 1998

Started on 9-22-98