Reattaching a Pulled out Seat

[Old#55]

As a passenger was sitting in the screw in helm seat, he leaned too far back and the screws ripped out of the deck. I tried the toggle boats but under my wooden deck is metal with holes in it. So the toggles just spun against the metal and would not tighten up- no grip. So I had to drill those out. But as you know, those toggles required a 1/2 in hole. So now I have 6 of those to fix. Decided to go with the epoxy sticks to refill the holes completely. It's about 4 inches to the foam and i decided for strength reasons to fill it all the way to the foam. First epoxy stick was going in and I was pushing it down all the way and it hardened up on me before I could get it all in and compacted. I got about 1/2 a stick in. So I know now to mix smaller batches at a time. I was pushing it down with a 4 inch machine screw and for kicks decided to see if the machine screw would thread in and hold with what I had in there. Boy did it ever, I was able to screw it in and out. But I will refill it all the way to the top and drill for a screw. The question is what size drill bit and stainless steel screw. Should it be a wood screw or a sheet metal screw/ Self tapping or not? Should I just fill those holes and move the base and drill new holes? I think more holes would make the deck under the seat weaker.

1996 Lund 1600 Pro Sport Adventure with the Ski and Fish package and a 90 HP OB Mercury

 

[dingbat]

The reality of the situation is that threaded fasteners have no place on a boat. Sooner or later, as you have found out, they will fail and pull out. Everything should be thru bolted with backing plates.

Having said that..I’ve had good luck fixing stripped holes in my deck hatch with marinetex and wood screws.

Fill hole with epoxy and thread a screw sprayed with silicon in the hole and let cure. Same process I use when attaching my transducer board to the transom.

Not sure how long it will hold up but worth a try

 

[Old#55]

Thanks Dingbat. I will give it a try. I figure this is now the least invasive move I can make after drilling those 1/2 holes. If it works for a few years, I can live with that. Otherwise, I'm cutting a 3 to 4 in. diameter hole in the deck in the middle of where the seat base sits. Then epoxy in the bolts and fender washers threads up or attach T-nuts.Then reseal the cutout with epoxy and install the base. A lot of work and may weaken the deck

 

[Lowlysubaruguy]

Can you rotate the base and get into good decking. Like your thinking drill your holes for your base. Myself I’d drill a 2” hole in the center and then just seal the wood after that cures then pull nuts washers into the base of the deck with a wire and silicone them and let that cure. Then carefully start all your screws and run them in with a blue lock tight or something help lock them. It will suck getting them out later but that’s another day.

 

[Old#55]

If this epoxy fix doesn't work I will be cutting out a center hole. Thanks for the wire tip on the nut and washer. Had not thought of that. That could lead to a smaller center hole as I would not have to fit my hole hand in there. The metal plate below the deck is a concern. I did drill through this when i tried to attach toggle bolts. Then I wondered...metal.gas tank? but I have not smelled any fuel in the holes and I know there is plenty of gas in the boat. So that is why I am shoving a lot of epoxy putty down there to seal them up.

 

[Scott Danforth]

the aluminum plate was your backing plate, as that provided the screws something to bite into

seriously doubt you could get enough epoxy down there to do anything as you will be trying to fill a cavity. plus the shear strength of epoxy is not that high, eventually the threads will strip out of them. you could try one of the titanium reinforced metal repair epoxies, however that is about $300 a quart.

toggle bolts should work, just use a rubber washer to give the bolt wings some traction to over-come the friction of the threads.