Installing deadlights on my vitage Irwin

[Peppercorn]

I've removed the crazed & cracked acrylic deadlights on my '78 30 Irwin. I'm to the point of affixing the first one to the cabin but of course am second guessing my choice of adhesives. I came across this stuff called Marine Goo which states it remains flexible for temperature variations. It is a contact adhesive and proclaims to be an adhesive / sealant. Who can ask for anything more? The PO's choice for some type of rigid epoxy and acrylic plastic is the reason I must change out these cracked & crazed deadlights. My next step is to glue in my polycarbonate winders. Has anyone used Marine Goo (states it is for above and below the water line and UV protected).

 

[Ted]

Installing deadlights on my vintage Irwin

Which plastic material are you using? Acrylic or polycarbonate? I have never used Marine Goo but highly recommend Dow 795 for adhering and sealing acrylic (Plexiglass) to fiberglass. There is a long cure time for this product so take your time and let it set before twisting your boat if you know what I mean. If your windows have a curve to them, make sure you place thin shims between the window and the boat. This will prevent all of the sealant from being squished out. I did mine last year and they came out looking better than a factory installation and no more leaks.

 

[Peppercorn]

I am using polycarbonate, and I actually was looking for Dow 795 when I came across this stuff. There is not much of any type of curve on it, at the moment it is well seated with masking tape. 795 is great stuff but only under ideal conditions, long cure time and strict temperatures during cure.

 

[Steve Dion]

One article that I read about using Dow 795 indicated that you can use screws to secure the acrylic in place. Once the material is fully cured you can remove the scews and fill the holes with some additional 795.

My Hunter Vision has large acrylic panels and they have been in place since 1994. I have done a couple of minor repairs on the caulk (DOW 795) and it works well.

 

[Merlin Clark]

I stumbled across "Marine Goop" at a local hardware store yesterday. Is this what you're referring to?
Bad light, very small print and old eyes kept me from finding out what it's composition is (if it was there) but I did notice the word "permanent" on the label.
I looked up the product online and it sounds like a strong adhesive/sealant but I'm very leery of anything "permanent". I've removed hardware and trim that was bedded with 5200 and it's never pretty. In my experience the bond between 5200 and gelcoat can be stronger than the gelcoat to fiberglass bond and I've ended up pulling the gelcoat off the boat. Or had the trim break.

I'm finding fewer and fewer places that I want to use any permanent adhesives for bedding.

 

[dscribner]

Peppercorn,

You want to use structural glazing tape to secure the polycarbonate or acrylic to the hull. Tremco SGT is one product. Set the tape 1/4" back from the edge of the glazing. Press FIRMLY into place. Then use Dow Corning 995 (not 795) which is a structrual sealant. If you mask the front edge of the glazing, and the hull within say 1/4" of the glazing, you can tool the sealant nicely so it looks like a gasket. 995 comes in colors too. GE sells a caulking tooling spay that works well too. Spray it on and it liquifies the surface just a little bit. If there's any reservations, this is the exact method for glazing many skyscrapers.

Don