Through bolt or lag on fore deck?

[stimmy]

I'm installing a life raft on the fore deck of my 1990 65' sportfish. I can't see any way to access the underside to through bolt; even the tender cradle appears to be lagged to the deck.
Is the deck strong enough to use lags? if not, how can I access the underside to through bolt?

 

[Cricket]

To thu bolt you probably have to pull down some headliner, maybe try to place it over a closet?
Thu bolting is the BEST option, that's a lot of weight besides the possibility of getting hit with water pressure from a wave.
Wouldn't use lags or sheet metal screws.
Depending on how thick the fiberglass is you might be able to get away with drilling and tapping the holes for bolts.

 

[racclarkson@gmail.com]

It's worth the trouble to thru bolt. Make backing plates to spread the compression.

 

[krush]

No need to drill holes at all. Use adhesive. No need for 5200, but 4000UV will hold it down plenty fine.

I removed the life raft holder from my deck, the long ass screws did nothing. It took me 1.5 hours with a torch and a putty knife to get it off.

The holes were leaking water. Don't drill them.

 

[jim rosenthal]

What he said. Don't make holes in a cored deck. It never works out well. If you have to, for deck hardware, do it the right way, with meal backing plates and taking out the core adjacent to the holes and filling it with epoxy. It's a huge pain in the ass.

 

[SEVEN]

Agree, agree, agree. No holes in the decks. It will cost you in the long run.

 

[stimmy]

I bought a 10 man raft, and it weighs about 150 lbs so I would be afraid to only glue the brackets to the deck. I am also concerned about anything attached only to the top layer of a laminated deck; I think in a sea, the force of 150lbs being buffeted about will delam the top layer.
So my next question is, how can I drop the headliner so I can through bolt?

 

[Bob Bradley]

I would use 5200 and stocky screws. As long as you bed the screws liberally with the 5200, it shouldn't leak.

I carry a 300 gal fuel bladder up on my bow. Full, it weighs approx. 2130#. Your liferaft's weight isn't even close. I tie it down to 4000# test pad eyes which are thru bolted to 1/2" SS plates measuring 3" x 6". The plates are then attached to the deck with 5200 and 8 #14 screws. Last year I decided to swap locations between the bladder and my raft, in order to get the raft positioned over an interior bulkhead. The screws came out ok, with effort, but the plates were an absolute pita to remove. This stuff is very strong.

 

[Cricket]

Just start pulling staples on the edges. Be prepared to replace it as you may not be able to put it back easily if you have to pull down more than just the 1st panel from an edge. make sure you coat the core after drilling the hole with epoxy before bolting everything together. Even better if you can dig out some balsa and pack it with epoxy. Good luck.

 

[jim rosenthal]

That is the right way to do it. Drilling holes and sealing them, even with 5200, doesn't seem to work for long. Water always finds its way down there, unfortunately.

 

[Cricket]

BB, unless you've removed the paint to get down to the fiberglass your pad eyes are glued to paint.
As far as 5200 goes I've been thinking for years that it somehow wicks water/moisture, especially when there's not a huge perimeter of the stuff, like with a screw or bolt.
Had an issue with the gunnel on my custom boat this fall from a rod holder bolt which apparently had been letting water/moisture in for years. It appeared to be bedded correctly.
After replacing 4 feet of coverboard we inserted fiberglass tube, glued in with epoxy for all of the bolt holes and also the main rod holder holes.

 

[stimmy]

The experience available here is outstanding; so many points of view provide plenty to think about and certainly reduce the likelihood of repeating others' hard-learned mistakes. I hadn't given the painted surface issue any thought; bonding to it seems unsafe.
The laminations in the walls going into the engine room are visible and they are foam between the FG layers, not balsa.
Does anyone know if the fore deck is foam or balsa on a 1990 65' sportfish? I'll find out if I drill.

BB, unless you've removed the paint to get down to the fiberglass your pad eyes are glued to paint.
As far as 5200 goes I've been thinking for years that it somehow wicks water/moisture, especially when there's not a huge perimeter of the stuff, like with a screw or bolt.
Had an issue with the gunnel on my custom boat this fall from a rod holder bolt which apparently had been letting water/moisture in for years. It appeared to be bedded correctly.
After replacing 4 feet of coverboard we inserted fiberglass tube, glued in with epoxy for all of the bolt holes and also the main rod holder holes.

 

[Cricket]

Foam or balsa you're still going to have to seal it up. if you remove some of the coring and pack with thickened epoxy it will help to stop compressing the 2 core when the bolts get tightened.
Stimmy, just think after doing this 1 project you will be an expert in core sealing, backing plates, headliner removal and installation.
Yes, owning a boat is fun.

 

[stimmy]

Foam or balsa you're still going to have to seal it up. if you remove some of the coring and pack with thickened epoxy it will help to stop compressing the 2 core when the bolts get tightened.
Stimmy, just think after doing this 1 project you will be an expert in core sealing, backing plates, headliner removal and installation.
Yes, owning a boat is fun.

LOL Thanks.
SO far, it's been 95% work and 5% fun. I hope to improve the ratio at some point. I've had quite a bit of F/G experience, so that part doesn't worry me; I don't like the idea of messing with that headliner and screwing it up. It doesn't look very accessible.

 

[Cricket]

Headliner is one of the things we've just never really figured out.
Last time we refurbed the salon we made plywood panels (bow to stern) drilled the holes for the lights, and covered them with vinyl that we glued and stapeled to the back. They're held up with the plastic hook and loop that's almost impossible to separate. All of the down below has stapled vinyl head liner, luckily we have a guy nearby that's a pro, and proud of it when he sends the invoice.

 

[Glory]

The only reason I don't have a hatch in my galley is that there will someday be a leak. Don't make any holes you can avoid.