By Show Me Step by StepPublished
Based on a video by SunBearGlassCraft.
Copper foiling is the step between cutting glass and soldering it. Every piece gets a thin strip of adhesive copper tape wrapped around its edge, and the solder later bonds to that copper. Rachel of SunBearGlassCraft calls it one of the most important steps, because how neat your foil is decides how neat your solder lines look. Uneven foil and little tags sticking out show through every seam.
Stained glass is held together one of two ways. Lead came is a grooved metal strip the glass slots into, best for big, simple windows. The copper foil method, made famous by Tiffany lamps, wraps each piece in tape so you can use small pieces, tight curves and 3D shapes. Most suncatchers and beginner panels use copper foil.
Foil comes in widths matched to glass thickness. The aim is an even sliver folded over each face, about the same on front and back.
Foil also comes with copper, black or silver backing. Use black backing with dark glass or a black patina so the edge does not glow through, and silver backing for clear glass with plain solder.
Burnishing presses the foil flat and tight against the glass. Wrinkles and loose spots let flux creep under the foil, and then the foil lifts when you solder. A plastic fid is the usual tool. A wooden clothespin or the back of a spoon works in a pinch.
Heavily rippled glass has an edge like a mountain range, and foil will not lie flat on it. Rachel runs those edges lightly over the grinder first, enough to take the peaks off. Inside curves are the other trouble spot. Press the foil into the curve as you wrap, crimp the straight edges first, then warm the foil on the curve by rubbing it and smooth it down with a fingernail.
Keep rolls in a sealed bag or box between projects. Copper tarnishes in damp air, and dull, oxidized foil takes solder less readily.
Work at a table under bright light so you can see the edge of the glass against the foil. Closing one eye makes centring easier at first. Foil a few simple squares before you tackle curves.
Before foiling, cut your glass and grind the edges. After foiling, solder the pieces together, then put it all into practice with a stained glass suncatcher.
10 steps · about 11 minutes.Check off each step as you go and your progress saves automatically.
Foil at a table with a bright light shining right on your work so there are no shadows on the glass edge. A table also lets you keep the right tension on the roll. A foil caddy keeps each width on its own spindle so the tape feeds off cleanly. Rachel keeps 3/16, 7/32 and 1/4 inch foil ready, and uses 7/32 most.
Tip
Keep the backing paper on until the moment you wrap, so the adhesive stays clean.
Stand a piece of glass on its edge and look at how thick it is. Stained glass varies a lot, and the foil width needs to match so the same amount folds over each face. Thin glass takes narrower foil. Thick glass needs wider foil, or there will not be enough copper left on the faces to hold the solder.
Tip
Sort your cut pieces by thickness first so you are not switching rolls constantly.
Turn textured glass sideways and look at its edge. Many textures look bold from the front but are nearly flat on the edge, and they foil like smooth glass. Heavily rippled glass has a wavy edge that foil cannot grip. Run those edges lightly over the grinder to knock the peaks down. It does not need to be glass smooth, only flat enough for the foil to lie down.
Tip
Use wider foil on very textured glass so it can follow the ripples.
Grinding leaves fine glass dust on the edges, and dust stops the foil adhesive from sticking. Wipe every edge with a damp microfiber towel, then let the piece dry completely. A clean, dry edge is what keeps foil from lifting later when it meets flux and a hot soldering iron.
Tip
Handle cleaned pieces by their faces so finger oils stay off the edges.
Pull out a length of foil and peel back the paper. Start on a straight edge that will sit inside the panel, not on its outer border. Set the glass edge in the middle of the sticky side so the same amount sticks out on each face. Turn the piece as you feed the foil around every edge, then overlap the end by about a quarter inch.
Tip
New to foiling? Close one eye while you line up the glass. Centring gets easier with practice.
Fold the foil overhang down onto both faces of the glass. You can pinch it a bit at a time all the way around. Or use what Rachel calls the ziploc method: pinch one end, then run your fingers along the edge like sealing a freezer bag. Fold corners neatly so the foil does not bunch up.
Tip
The ziploc method is easier on your fingertips if you foil a lot of pieces.
Burnish the outer edge first, then the faces. Rub a plastic fid firmly along the foil until it is tight against the glass with no wrinkles or bubbles. Wrinkles let flux creep under the foil, and the foil then lifts when you solder. Go over every edge and both faces of each piece.
Tip
Run a fingernail along the foil afterwards. If you feel a ridge, burnish again.
Start a concave piece on a flat edge the same way. When you reach the inside curve, press the foil down firmly into the curve as you go, using a finger on your other hand to follow the tape. Look under the foil at the curve to make sure there are no gaps. Crimp the straight edges first and save the curve for last.
Tip
Slow down on curves. Most torn foil comes from pulling too fast round a bend.
Rub your finger back and forth over the foil on the curve. The friction warms the copper and makes it soft enough to bend without tearing. Then press it down with your fingernail rather than the pad of your finger. For concave pieces, burnish the faces lightly first, then the edge, so the foil does not lift while you work.
Tip
If the foil does tear, trim the torn corners with a craft knife or refoil that section.
Hold each foiled piece up to the light and check every edge. The foil should be even on both faces, tight, and free of wrinkles. Trim any tails or overlapping ends with a craft knife, and make sure no foil end sits on what will be the outer edge of the panel. Fix problems now. They are much harder to hide once soldered.
Tip
Lay all the foiled pieces back on the pattern to check they still fit with the added foil.
Keep going
How to Make Garden Plant Markers - 5 Cheap and Easy Ideas
How to Copper Foil Stained Glass
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