Strengths
What it’s good at
Permanent, high-strength structural bonding and sealing above and below the waterline — the marine benchmark for thru-hull fittings, hull-to-deck joints, and RV repairs.
Limits
Where it falls short
Permanent bond that is extremely difficult to remove once cured. Slow cure rate (up to 5–7 days) that requires moisture to cure.
Specifications
Manufacturer specifications
Every number below is quoted from the manufacturer’s own documentation, linked at the end of the row.
- Working time
- 4 h — Open tooling time up to 4 h before skinning[1]
- Initial set
- 12 h — Tack-free time typically 12 h at 73 °F and 50 % relative humidity[1]
- Full cure
- 5 days — Full through-cure for a 1/8-inch bead takes 5–7 days at 73 °F / 50 % RH[1]
- Strength
- 700 psi — Tensile strength according to ASTM D-412 with 68 Shore A hardness[1]
- Max service temperature
- 190 °F — Service temperature range −40 °F to 190 °F[1]
- Min application temperature
- 40 °F — Do not apply at temperatures below 40 °F or above 100 °F[1]
- Water resistance
- 100 % waterproof for permanent structural joints above and below the waterline in salt and fresh water[1]
- Cured color
- White[1]
How long it takes
Working time, clamp time, and full cure are different things — this is the order you experience them in.
- Working time4 h
- Initial set12 h
- Full cure5 days
Sources
Where these facts come from
- [1]3M Marine Adhesive Sealant 5200 Technical Data Sheet — 3M Marine Care Division · Technical data sheet · Retrieved 2026-08-14
