Repair Sealing deck to hull

[Clyde]

I want to seal the deck to the hull to prevent leakage on my 1977 Sunfish. 3M 5200 or 4200?

 

[Alan S. Glos]

Thickened epoxy and many, many spring clamps may work better. Signal Charlie can post photos.

Alan Glos
Cazenovia, NY

 

[beldar boathead]

I want to seal the deck to the hull to prevent leakage on my 1977 Sunfish. 3M 5200 or 4200?

Definitely not 4200.

Have you checked and found leaks?

 

[L&VW]

I want to seal the deck to the hull to prevent leakage on my 1977 Sunfish. 3M 5200 or 4200?

Small amounts of leakage is tolerable.

Before I'd remove the aluminum rubrail, I'd do a [low] air pressure test to determine the exact source of your water inflow.

Daggerboard leaks are a whole 'nother story!

Or, have you already removed the deck?

 

[beldar boathead]

It’s a minor difference - but a difference - you are bonding the deck to the hull, not sealing it. A bonding agent, like epoxy, is going to be best. 5200 is a bit of a hybrid and may work. But to my knowledge , boat builders use epoxy or another glue to bond decks to hulls, and you should do the same.

 

[Tops]

Thickened epoxy and many, many spring clamps may work better. Signal Charlie can post photos.

Alan Glos
Cazenovia, NY

One article from @signal charlie from their blog:

Sunfish Foam Repair

And a cute and concise video: