Glass By Barb

  • Fuschia window in powder room.

When to Choose Lead Came

The what of a project determines both technique and materials.

Lead came is generally used for windows, sidelights, and transoms. It can also be used for hanging panels, in which case it requires a rigid frame of another material for adequate support.

Lead came is the most demanding and least forgiving of the methods, but it gives clean, even lines. With centuries of tradition behind it, it is what many consider to be "real" stained glass.

Assembly

Stained or leaded glass projects are assembled on a sturdy piece of plywood or particle board larger than the design. Narrow wooden strips are nailed along two adjoining sides, usually at the exact top and left of the pattern, providing a rigid barrier against which to push and fit the glass and lead as it is assembled over the pattern.

The glass pieces are assembled much like a jigsaw puzzle, with additional grinding, as needed, to fit. Lead came is stretched to strengthen and straighten it, then cut to fit along the sides of the individual glass pieces. The glass pieces are then slotted into the channelled sides of the lead, leaving no visible edges.

In the case of long vertical lines, zinc came can be used, instead of lead came, to lend structural support to the project.

Unlike a jigsaw puzzle, the separate pieces of glass and lead will not stay together without assistance. As each piece of glass is fitted, a scrap of lead came is tacked in beside the lead or glass edge with a horseshoe nail in order to hold it in place until the adjoining piece of lead and glass are ready to be added.

When the entire project is finally pieced and fitted, the lead joints are fused with solder. The project is carefully turned over (held securely between pieces of board like filling in a sandwich), and the joints on the reverse side are soldered.

  • Fitting glass and lead over pattern.
  • Closeup of fitting glass and lead.
  • Soldering joints on a lead came project.
  • Cementing a lead came project.
  • Picking cement along the lead edges.
  • The first brushing after cementing.

Cementing (Traditional Method)

At this stage, the window is still very fragile, wobbly and easily destroyed, so cement is worked inside the lead channels, filling the spaces between lead and glass. Not only does this help with strength and rigidity, it also makes the window airtight.

Once the cement is worked inside the lead channels from each side of the panel, the excess is brushed off. The lead and glass are still dirty and smeared from the cement. Whiting, a fine polishing compound, is sprinkled generously on each side of the project, rubbed on by hand, and pushed up against the lead edges. The panel is left overnight to let the cement set and to allow the whiting to absorb excess liquid from the cement.

The next day, the artist runs an orange stick (or other pointed wooden object that won't scratch the glass) around the glass pieces to clean cement from the lead edges. This is followed by brushing to clean the glass. It takes repeated brushing, picking and polishing to remove all traces of the cement and whiting before the finished project is finally sparkling and clean.

Silicone - If the artist chooses to use silicone instead of cement, each piece of glass is siliconed in place as the project is fitted together. Silicone is a cleaner method, but it presents other challenges — particularly if it becomes necessary to undo previously fitted pieces. The artist must also be diligent to avoid getting silicone on visible glass surfaces, as silicone is difficult to remove.

Structural Support

Over time, especially in large windows, lead will sag. This tendency calls for reinforcement. Strips of metal rebar are soldered to the lead and extended across the window to fit into notches in the window framework. If carefully done by following the lines of the window design, the rebar will generally go unnoticed.

Copper restrip can also be inserted inside the lead channels, or the artist can use lead came with copper restrip inside the channel. If the window is very large, though, or if it will be subjected to extra stress (such as in a door), it is best to incorporate rebar.

  • A coil of copper restrip.

Pictorial Story - Lead Came Process

Click here to view a pictorial story of the creation of a leaded glass window. This document shows the complete lead came process.