Diferential expansion

[sighmoon]

Is it OK to stick metal through-hull fittings in the hull with epoxy resin, or would the differential expansion of the metal, and the fibreglass cause it to crack open when it gets warmer(or colder)?

Simon

 

[billcowan]

Coldest seawater 0
Warmest seawater 25 ?

difference is only 25 degrees, epoxy is very strong, I doubt it would crack. But hopefully you are using normal fittings with a flange and nut, so why not use something gooey to seal them instead.

 

[vyv_cox]

You may well get away with it but it is not good practice. Much better to use Sikaflex 291 or something similar to provide a flexible and absorbent joint between hull and fitting. This allows for thermal expansion, not a very likely problem, and a whole variety of impacts, flexing, minor movements and other more realistic circumstances.

 

[Topcat47]

Epoxy them in place by all means but you have to resign yourself to never getting them out again (evenif they still leak). I'm not a fan of Sikaflex, I'd use Life-seal or Life-caulk myself. If the holes are a slack fit, you can always coat the fitting in release agent before epoxying the hole, then it should come out when the glue has set. You'd still need to caulk the fittings before launch if you did that tho'.

 

[Brian_Moffat]

The answer is yes - but only if you want to sink the boat!

Use ONLY approved sealants for thru-hulls

Invalidation of insurance is otherwise automatic and instantaneous from the time of installation.

do NOT use compounds marked DC (Deck Compound) - use that where it says - on the deck

You will need two people ( one inside and one outside)

and clean up the overflow immediately - or let it dry and cut it off with a box knife - your choice