Case 1

Remedial

The deteriorated sealant should be completely removed, the edges and surfaces cleaned thoroughly and a compatible sealant selected so that adhesion is ensured between the contact surfaces of glass should be used. Solvent cleaning should be as follows:

1. Clean dirty glass edges with solvent such as isopropyl alcohol (IPA). Use proper safety and handling procedures when using cleaning and degreasing solvents.
2. Utilize a two-rag method when solvent cleaning: one for wetting and one for drying surfaces. pour cleaning solvent into a clean, dry, lint-free cloth rag. Do not dip the rag into the solvent container, as it may contaminate the solvent.
3. Wipe vigorously to remove surface contaminants. Check the rag to see if it has picked up contaminants. Rotate the rag to clean area and re wipe until no more dirt or oily material is picked up.
4. Immediately wipe the solvent cleaned area with a second clean, dry rag. The solvent should be removed with a dry rag before it evaporates: otherwise the cleaning procedure will be ineffective.

This should result in the removal of dust, dirt, oil, or moisture from the sealant contact surfaces.

Priming:

1. Ensure that the appropriate primer is selected and is within its stated shelf life and is applied in accordance with the sealant manufacturer’s instructions.
2. Priming is not a substitute for solvent cleaning. Therefore, solvent cleaning must be performed prior to priming.
3. Pour a limited amount of primer into a clean container. Replace solvent container cap to prevent deterioration and contamination of the primer.
4. Dip a clean, lint-free cloth rag into the primer and gently wipe the primer onto the surface. For hard to reach areas, apply the primer with a natural bristle brush. Some primers are to be applied in thin film, while others require heavy coats.
5. Over priming can cause loss of sealant adhesion. If too much primer is applied (as evidence by a residue or powdery build up on the metal surface) wipe off the excess primer with a clean, dry rag.
6. Allow the primer to completely dry. Some primers require several minutes to dry, while others may require an hour or more in open air or in cold weather prior to sealant application.
7. The silicone sealant should be applied as soon as possible to prevent build up of dirt, moisture and other contaminants from affecting the adhesion of the silicone to the substrates. As a general rule, prime only the joints that can be sealed during an eight- hour workday.

(Refer to sealants) Glass panels with visible cracks should be assessed critically and replaced if necessary.