Bostik Chem-Calk 550

Application

Install backup material or joint filler as specified

and primer when applicable. Apply Chem-Calk® 550 polyurethane sealant in a continuous operation using a positive pressure adequate to properly fill and seal the joint. The Chem-Calk® 550 is pourable and will tend to seek its own level. Tooling is recommended to ensure proper wetting of the joint surfaces.

Mixing

Chem Calk® 550 is a multipart sealant, provided as base, activator (or curing agent) and color pack. All the accelerator and appropriate color pack must be thoroughly mixed with the base to avoid uncured areas and/or color streaks. Failure to follow mixing instructions implicitly can result in spotty cure, random cure or complete lack of cure of the sealant. Do not attempt to mix partial units, as the exact ratio of curing agent to base is essential for optimum performance.

See Vendor Technical Data Sheet for more info.

Clean-Up

Excess sealant should be dry-wiped from all surfaces while still uncured, and followed with a commercial solvent wipe. Contact Technical Service for specific solvent recommendations. Should sealant accidentally begin to cure on adjacent porous surfaces, the excess sealant should be allowed to progress through the initial cure or setup. It should be removed promptly by abrasion or other mechanical means. CURED SEALANT IS USUALLY VERY DIFFICULT TO REMOVE WITHOUT ALTERING OR DAMAGING THE SURFACE TO WHICH THE SEALANT HAS BEEN MISAPPLIED. Bostik Findley recommends the use of Bostik® Hand & Tool Towels for easy removal of uncured CC550 from surfaces, hands and tools.