What to use to fix corroded seat pedestal fasteners

69fastback

We took the boat out today and had a seat malfunction. The co pilots seat pulled some of the bolts out that mount the pedestal to the floor. Obviously there are nuts under the floor that the bolts go through the seat pedestal, through the floor, and screw into and they corroded away. I would have to assume I’m not the first to have this issue and the issue being there there is no real access to get any sort of nut back under the floor, to bolt the seat pedestal back to. What’s the fix?

LaRea

No access at all to the underside?  Seems like you'd have to go with some sort of stainless toggle bolt.  Maybe this:

https://www.walmart.com/ip/Garelick-EEz-In-Stainless-Steel-1-4-20-Toggler-Bolt-Anchor/32741219

69fastback

LaRea said:

No access at all to the underside?  Seems like you'd have to go with some sort of stainless toggle bolt.  Maybe this:

https://www.walmart.com/ip/Garelick-EEz-In-Stainless-Steel-1-4-20-Toggler-Bolt-Anchor/32741219

Do you think a toggle bolt spreads out enough to distribute the pressure on the bottom of the fiberglass floor so it won’t damage the fiberglass? 

Cableguy Greg

I thought that they were held in place using a T-nut on the bottom.

69fastback

Cableguy Greg said:

I thought that they were held in place using a T-nut on the bottom.

They may have been, but I can't get to the bottom. 

skennelly

I would think a toggle would have more spread than a t-nut.  I've seen people use toggles to install fishing downriggers when access to the gunwale isn't possible.

69fastback

Awesome. I’ll give it a shot and see if I can make it work. Thanks for the suggestions. 

raybo3

The problem with the toggle is you have to make a big hole for it. I would look for a way to access the area and put a backing plate or see what is already there.

skennelly

http://www.toggler.com/ask_the_expert_blog/whats-the-best-anchor-for-attaching-pedestal-seats-on-my-boat.php

Can you cut a 6" hole in the floor and put an access plate in it's place?

69fastback

I got some toggle bolts from West Marine that I think will work, as long as they hold up. The reviews on them aren’t great, in that they aren’t real strong, but I’m going to give them a try and i don’t think it’ll be an issue getting them in the hole. From reading the reviews I think the key is to just not over tighten. I’d go put them in now but we are under an extreme weather watch with the possibility of F5-6 tornados, so I think I’ll stay home for now. 

69fastback

Well, it’s back in. I am slightly concerned about the pin breaking in the toggle bolt, but time will tell. I’m carrying spares in the meantime. I was able to drop the toggle bolt in the floor and secure it to the floor using a nut and had enough room to set the pedestal over the nut and it clear. Then I used another nut to secure the pedestal to the floor. I just need to go back and trim the top of the bolt off flush with the nut before someone breaks a toe. 

Thanks to everyone for the suggestions. 

Black_Diamond

Should have been SS fasteners. They just do not corrode away in any normal boating application. More likely the nuts were not the locking type and just backed off. 

Those toggle bolts are not really meant for that application let alone the vibration issues... you might get lucky!

69fastback

Black_Diamond said:

Should have been SS fasteners. They just do not corrode away in any normal boating application. More likely the nuts were not the locking type and just backed off. 

Those toggle bolts are not really meant for that application let alone the vibration issues... you might get lucky!

That’s actually exactly what those toggle bolts are meant for. They are advertised to mount a pedestal seat to the floor, and are kept next to the pedestal seats at West Marine. 

While stainless steel is more corrosion resistant, it will still corrode.