Henkel Armstrong A-40 Epoxy Resin

Surface Preparation

Surfaces to be bonded should be clean and dry. For critical applications, refer to our suggested surface preparation procedures — Bulletin No. 964

Application

Property mixed material may be applied to the surfaces being bonded with a mechanical applicator or any clean tool such as a metal spatula, trowel, wooden coffeestirrer, or equivalent. The material should be spread thinly and evenly. Glue lines as thick as .101” will provide good strength but the general rule is—the thinner the better. The important thing is that the surfaces being bonded are thoroughly “welted out” with the resin system. Once applied, the joints being bonded should be assembled immediately

under no circumstances would this open assembly times exceed 30 minutes. No pressure is required other than that necessary to hold to assembly in position until the resin cures. Then uncured material may be removed from mixing utensils etc. with solvent such as Methyl Ethyl ketone (MEK) and/ or Cellosolve or equivalent.

Mixing

The mix ratio for A-40 is 5 parts of Part A to 2 parts of Part B by weight. The concentration of Part B may be varied = 10% of the recommended amount without seriously affecting the physical properties other than the working life. For best results, the temperature of the Part A and Part B should be between 70° to 90°F. before mixing. Lower and higher temperatures can be employed but the working life will be reduced as the temperature is increased and the working life will be extended as the temperature decreases. At lower temperatures, the material is quiet vouches and not as easy to mix.

A-40 should not be thinned with solvent at any time. The Part A and the Part B must be thoroughly mixed before the system is ready for use.

Curing

A-40 should be cured as follows: 7 days at room temperature or 2 hours at 210°F. Where military specification qualification is necessary the 2 hour cure at 210°F must be followed.