1) Surface Preparation (Don’t skip it)
Surfaces must be structurally sound, stable, dry, and free of dust, loose material, oils/grease, release agents, curing compounds, and other contaminants.
Impervious substrates (tiles, glass, metal)
Use a two-wipe process with clean cloths. A suitable cleaner/solvent such as white spirits may be used; change cloths frequently to avoid spreading contamination.
Concrete and porous surfaces
Ensure concrete is cured for at least 28 days and fully dry. Remove dust/friable material so the sealant can key properly.
Timing: Plan prep so the joint is dry—sealing over dampness invites adhesion failures.
Pro Tip: Mask joint edges before gunning for a neater finish and faster clean-up—less rework, cleaner handover.