Yesterday, I set about working on a modern-look forest scene of birch trees. I cut, ground, foiled, polished and then patina'd the entire piece... And promptly dropped it.
And so, I have this opportunity to a) gain some more experience in replacing broken glass, b) take a few photos and blog a tutorial (the first time I had this experience, I frantically googled every tutorial I could find, and found that each one taught me a small nuance that the others didn't - maybe I can add to the internet's library of knowledge, here) and c) try to learn from this, make the best of a stupid mistake and see the sunny side (instead of screaming and throwing the panel across the room).
Start with your sad broken piece, a glass cutter, a pair of pliers, your safety glasses and all of your most positive energy!
Step 1: Use your cutter to score the broken piece in all directions, from edge to edge. Go crazy with score lines but be careful not to run onto any of the next (unbroken) pieces. Please note that I'm not using my "good" glass cutter for this part, as I don't want to accidentally hurt the cutting wheel by running it multiple times over pre-existing scores.
Step 2: Flip the piece over and use the ball end of the glass cutter to start cracking some of your crazy score lines. You will need to be patient with this - the scores don't always run easily in small, cramped areas, and it's tempting to start waling on the glass. Make sure to again stay within the solder lines of the broken piece and don't accidentally crack its neighbor!
Step 4: Once you have some of your scores cracked and some pieces in the center start to fall out, flip the piece back to the front side and survey your damage. Tap out any loose pieces with the ball end of the cutter, if you can. Don't forget that you're creating a ton of tiny shards of glass, and some of them may have flown up into the air! Keep your safety glasses on and your face away from the project and don't shred your hands in an attempt to sweep all those shards off your workspace.
Step 5: Time to use some finesse and a lot more of your patience. Your pliers will be helpful in getting a good grip on the edges of the broken piece. Try to pull each piece out carefully, without disturbing the copper foil on the adjoining piece of glass.
As you pull pieces out, you'll find that you can gently wiggle many loose with your pliers. A few may not be cracked/broken enough to remove, so re-score if you need to, flip the piece over, tap away with the ball end of the cutter, and try to get all of the glass out of its foil edging.
If you have successfully cleaned out all of the broken shards, you should now have a glass-free hole where your broken piece was.
Step 6: Flux up the copper "frame" which the glass left behind, and (carefully!!!) heat the solder line until you can pick at the inner edge with tweezers. As the solder heats and the foil starts to release from the neighboring foil-wrapped glass, gently pull the the foil away. Go slowly, make sure the solder has released the foil before pulling, and peel it away from all neighboring pieces of glass without disturbing any of the foil on surrounding pieces.
If you accidentally pull or rip the foil from a piece which isn't broken/being replaced, you will have to clean and re-foil the edge of that piece.
Step 7: Now that the old foil is gone from the open space, you will need to clean any excess solder drips and blorps (that's a technical term, trust me) from the inside of the hole with your iron so you can cut and fit a precise new piece of glass into the space.
Taking a moment to step back and survey the carnage, you will notice that I did an excellent job in cracking as many pieces as possible when I dropped my project. I've removed all of the broken glass and old foil and have readied the entire piece for the next step!
Step 8: Trace the open space onto a new, replacement, piece of glass. I probably could have simply measured the space in this case, since my pieces are measurable rectangles.
Cut, grind, foil each new piece of glass as usual. Before foiling, test to make sure the glass fits well into the open cavity.
Step 9: Lay the cut piece into its new home! As you can see by the photo below, the new piece will need a little lift from underneath to match the height of the pre-existing soldered pieces (due to the edge capping as well as the full solder beading, the panel will sit higher than the edges of the new piece).
Some people use pennies to elevate their new piece, but my pockets were empty this morning, so I used a piece of 14 gauge wire bent to support the piece of glass, making sure it layed flat and level.
Since I had 5 replacement pieces, I repeated the process for each before starting to solder... Making sure that they were all at the correct height before soldering into place.
Step 10: With all new pieces in place, flux 'em up, tack them in and solder!
Flip over and repeat!
Holy carp - I think it's fixed! Don't drop it again, dummy!!!
Step 11: Finish that piece! Clean, polish and add patina (if you were using it).
Now no one can tell you ever dropped it!