Lead Came Assessment
Lead came is the term used for the metal structure which weaves through the window in support of the glass. Lead came is an alloy comprised mostly of lead but also includes other metallic elements in small amounts: tin and nickel.
Lead came has a service life of 100-120 years under normal atmospheric conditions. Extreme temperature cycles and atmospheric pollution may act to shorten the life of the lead. Listed below are symptoms of stained glass in need of repair.
Symptoms of Lead Came Failure
Brittle Lead. Lead came becomes increasingly brittle with age and is the primary reason that the life expectancy of stained glass is estimated at 100-120 years. Cracks in the soldered joinery of the lead are a good indicator that the lead is nearing the end of its serviceable life.
Out-of-plane Bowing of stained glass is a progressive failure of the lead structure of the window. Bowing can lead to broken lead joints and broken glass which further weaken the window. Causes can range from inadequate bracing and support to improper glazing techniques during the initial crafting of the window.
Oxidization presents as a crusty scale on the surface of the lead. Once formed, it continued to etch away the surface of the lead much like corrosion in steel.
Replacement of Deteriorated Lead Came
It is not possible to replace deteriorated lead came in place. The window must be removed for re-lead restoration. Re-lead restoration is the process of dismantling the stained glass window, cleaning the glass, and reassembling the window with new lead came. Not all windows deteriorate at the same rate. Even within the same church, some windows may require re-restoration while others may not be in the same critical condition. Windows are accessed individually and recommendations are made accordingly.
Stock section of Lead Came
Stained Glass assembly with new lead came