Large stained glass panels of more than 3 feet square require reinforcement for optimal longevity. Panels constructed with lead came are reinforced with brass, zinc or steel rebar, while panels made of copper foil can be reinforced with a fairly new product called copper reinforcing strip. Each type of reinforcement extends from one side of the stained glass panel to the other, though the copper reinforcing strip is hidden in the pattern while the rebar creates a shadow of the bar when viewed from the opposite side.
Cut the strip of rebar with the metal saw so that it extends from one edge of the panel to the other. The number of reinforcing bars you use depends on the size of the panel and the design. There may be vertical and horizontal lines in the design that will help hide the reinforcing bar.
Apply flux to the bar with the brush and melt a thin layer of solder so that it covers the reinforcing bar. This is called "tinning," and it facilitates the attachment of the bar to the window with solder.
Place the rebar on the panel along the horizontal or vertical line where it will be fastened. Mark along the line in even increments the seams where the rebar intersects with the lead lines in the glass.
Cut pieces of the wire long enough to wrap around the rebar and hold it in place. Solder these pieces of wire to the lead seams at the marks made previously.
Set the rebar back in place, wrap the wire around the rebar to hold it in place, and apply flux and solder at some of the seams for further reinforcement.
Make sure all the pieces of glass in the panel are wrapped with copper foil and correctly placed on the pattern, ready for soldering.
Cut a piece of copper reinforcing strip with the tin snips to extend from one side of the panel to the other, taking into account any curves along the way so that it is long enough. It should extend about 1/4 inch outside the edge of the panel on either side when it is in place.
Lay the copper reinforcing strip down along the chosen seam, setting weights on it as needed to keep it in place.
Set enough strips in place along vertical and horizontal seams to adequately reinforce the panel. Where the strips intersect, cut one and bend about 1/4 inch in an "L" shape along the piece of glass closest to it. The other side of the strip should bend along the other side of the intersection so that they aren't overlapping each other.
Apply flux along the copper foil seams and solder both sides of the stained glass panel.
Bend the 1/4-inch pieces along the edge along the side and solder them in place before framing the panel.
The rebar is applied to the stained glass panel after it is soldered together and cemented. The copper reinforcing strip is set into place before the panel is soldered together.
Always work in a well-ventilated area, and do not touch your face or mouth when working with lead.