THE REPAIR PROCESS – The original glass was very thin and had been cut into large shapes which made them especially vulnerable to movement. The lead work was very thin and weak and was not supporting the glass very well. Once the window had been removed and dismantled, all the broken pieces were gathered together for edge-bonding. As the glass was thin, the lead was also of a thin profile, just wide enough to accommodate the glass and leadlight cement (waterproofing material). This meant we had to replace like for like and so we could not edge-bond the glass with resins as they may have required back-plating. So we used an acid-free silicone which was not only waterproof, but could also flex with the movement of the window.