3M 1945 B/A

Surface Preparation

Substrates must be clean, dry and free of oil, grease, release agents or other contaminants. Substrates such as aluminum can be cleaned satisfactorily using clean dry rags or unsized, lint-free cheese cloth that has been soaked in common cleaners* such as called out in MIL-C-38736.

Application

3M™ Scotch-Weld™ Structural Adhesive Primer EC-1945 B/A can be applied by dipping, brushing or spraying. For optimum results, Scotch-Weld Primer EC-1945 B/A should be applied to a dry film thickness of 0.2-0.7 mils (0.0002-0.0007 inches).

Mixing

Thoroughly mix the base and accelerator at a one to one (1:1) volume ratio. Scotch-Weld Primer EC-1945 B/A, at 77 ± 2°F in a sealed container, has an application life of approximately 8 hours. (Periodic agitation is necessary.)

Curing

Scotch-Weld Primer EC-1945 B/A is an amine cured epoxy in a blended ketone solvent. The primer must contain no solvent prior to the application of the adhesive or sealer. A minimum of 60 minutes @ 75° ± 5°F is the suggested drying time prior to adhesive or sealer application. Higher temperatures will reduce this drying time and the following is the suggested cure cycles. (a) 24 hours @ 75° ± 5°F (b) 1 hour @ 75° ± 5°F followed by 30 minutes @ 180°F or 5 min. @ 250°F.

Note: Cure cycle (b) is the suggested cure to provide maximum toughness and corrosion protection of the primer.

Clean-Up

All containers, tools and equipment normally re-used in handling this product should be cleaned before the product has an opportunity to set up or cure. This can be done easily with conventional organic solvents such as methyl ethyl ketone.* Cured Scotch-Weld Primer EC-1945 B/A can be removed by soaking in a methylene chloride type stripper.*

*Note: When using solvents, be sure to follow the manufacturer’s precautions and directions for use for handling such materials.