Teak First 405
I have a 1986 First 405 - no teak decks but teak on cockpit seating and companionway. I removed the teak at the compaionway as it seemed soft, thinking water had gotten into the core. Turns out there was no core there, just thin glass. But, the teak was extremely well installed - to a point that it ripped up the gel coat. Turns out they had screwed and bunged the teak with a 3M-5200 like material beneath it - that was in amazingly good condition after 23 years - still agreesively held and flexible - and covered the entire area. No leakage from the screws anywhere, and it turns out you don't even need the screws.
The most of the bungs were worn through exposing the screw heads, so I removed the screws, drilled a 3/8 hole to the glass, and epoxied new bungs in sans screws. Also removed all the seaming and replaced. It was a lot of work for just the cockpit, so all the decks could be a major undertaking. Good news is that the 5200 like material does a great job sealing, so deck cores should be fine.
I had a few minor blisters and some gel cracking here and there, but nothing serious. The only other issue was at the anchor locker. They apparently drilled the pin latch hole directly into the deck core, unsealed. This allowed water to permeat the core around it. Fortunately for me it did not go far, and was easily cut out and replaced from inside the locker.
Hope this helps!
