The window is cleaned and checked. When damage has started, the window may have to be partially disassembled and cames replaced. The means of installing should not interfere with the natural flat-plane expansion and contraction of the panel. Any protective covers should be adequately ventilated. Any flaws in solder joints will be attacked.
Corrosion causes weakening, and when a solder joint is affected can contribute to sagging .
Where a protective cover is used, improper ventilation can cause microorganisms to thrive, both damaging wood and adding to the oxidation of the cames. A thin film of oxidation on lead and aluminum is actually good, acting as a barrier to further deterioration. Long-term exposure to moisture from improper venting of protective glazing can cause oxidation and corrosive processes to continue beyond the beneficial stage. Cleaning with a pH neutral detergent, re-soldering of affected joints, and properly venting protective glazing. The design of a window determines what bracing and support is needed.