Metalset® A4 is a powerful epoxy adhesive that has been used for years by all branches of the U.S. Military as well as every major airline and auto manufacturer in the world. Metalset® A4 is used for hundreds of industrial bonding applications and offers excellent adhesion to porous or non-porous surfaces. It can be applied to vertical surfaces without sagging and cures overnight with negligible shrinking.
Once cured, Metalset® A4 offers good machining qualities (sanding, drilling, tapping), and resists alkalies, dilute acids and solvents. Applications include stopping leaks in pipes, valves and tanks (i.e. car gas tanks), bonding like and unlike surfaces, filling metal joints, dents, etc., anchoring bolts in wood, concrete, and repairing metal surfaces.
Bell Spec - Metalset A4 meets all quality requirements and can be certified to Bell Spec 299-947-099 Rev. D (see below for details)
Safety - Use in a properly ventilated area (“room size” ventilation). Wear safety glasses, long sleeves and rubber gloves to minimize contamination risk.
Store and use material at room temperature (73°F/23°C). This product has a limited shelf life and should be used as soon as possible.
A clean, dry surface is essential for successful adhesive bonding. Porous materials are simple to bond, provided they are dry. The surface should be sanded till clean followed by wiping surface with solvent (acetone, MEK, mineral spirits). Let solvent evaporate fully before applying A4.
Non-porous surfaces (metals, plastics, coated woods) should be sanded, sandblasted or chemically etched. If sanding or sandblasting, follow with solvent wash. Let solvent evaporate fully before applying A4. Epoxy adhesives do not perform well on metals such as nickel, chromium, tin or zinc or on soft thermoplastics like polyethylene. An option would be to try a polyurethane adhesive (such as URE-BOND® from Smooth-On).
Because no two applications are quite the same, a small test application to determine suitability for your project is recommended if performance of this material is in question.
MEASURING, MIXING, APPLYING...
Metalset™ A4 is mixed one part A to one part B by weight or volume. If dispensing from tubes, squeeze out equal amounts from each tube. Try to be as accurate as possible. Mix thoroughly for 3 minutes to a uniform grey color (no streaks) and apply to prepared surface at a thickness of 1/32” - 1/16” (0.08cm - 0.16cm). Fit other surface over epoxy and apply even pressure using clamps or weights. Handling time is 4 hours. Full cure is 16 hours.
Metalset™ A4 will cure in 16 hours at room temp. (73°F/23°C). Applying mild heat will cure A4 faster–150°F/65°C for 2 hours.
Post Curing - After A4 has cured at room temperature, heating the epoxy to 150°F (65°C) for 4 to 8 hours will increase physical properties and performance. Let cool to room temperature before moving bonded substrates, machining, etc.
CERTIFYING TO BELL SPEC...
Metalset™ A4 meets all quality requirements and can be certified to Bell Spec 299-947-099 Rev. D, IOM 80-2017-017. There is a fee associated with certification. Contact Smooth-On, Inc. for further information at (610) 252- 5800 (8:30-5:30 Eastern Time).