3M Scotch-Weld Structural Void Filling Compound EC-3524 B/A FST

A two-part, low-density thixotropic epoxy void-filling and edge-sealing paste for aircraft honeycomb sandwich structures, supplied in the FST (fire/smoke/toxicity) grade for cabin-interior use. It is used for edge close-out, gap and mismatch filling, honeycomb reinforcement and as an abradable/fan-track filler, and cures at room temperature to a sandable, paintable surface. This is the FST-compliant variant of the EC-3524 B/A family (typically supplied black).

Angad Aviation supplies this 3M product with full traceability and documentation — request a quote for current pricing, pack sizes and lead time.

• Brand: 3M
• Part No.: EC-3524 B/A FST
• Type: two-part epoxy void filler / edge sealer
• Color: black
• Work life: approx. 90 minutes at 24C (75F)
• Sandable: within ~3 hours of mixing at 24C
• Full cure: 48 hours at 24C (75F)
• Rheology: thixotropic (non-sag)
• Compliance: Flammability per FAR 25.853(a) and (b); FST grade addresses fire, smoke and toxic-gas (smoke density/toxicity) requirements for aircraft interiors