Sealant for stern seat back bolts 240 Sundancer

[KHE]

I took my stern seat out last fall to have it reupholstered and the back rest had through bolts through the transom. The original sealer looked to be a non-hardening sealer and I'd like to know what it's called so I can properly re-seal the bolts when I install the seat.

Thanks.

 

[KevinC]

I took my stern seat out last fall to have it reupholstered and the back rest had through bolts through the transom. The original sealer looked to be a non-hardening sealer and I'd like to know what it's called so I can properly re-seal the bolts when I install the seat.

Thanks.

When you mention the bolts through the transom I am guessing you are referring to the transom locker area. I think that area is all fiberglass so more than likely it is not sealing a core. If that is the case I do not believe the sealant was doing anything more than holding the finder washers and bolts in place and any outdoor silicone would probably suffice. I have taken off many of these bolster bolts and that is all I could see that they were doing - besides making it hard for me to remove them. Could probably use nylon locking nuts but that would probably have been more expensive.

-Kevin

 

[KHE]

When you mention the bolts through the transom I am guessing you are referring to the transom locker area. I think that area is all fiberglass so more than likely it is not sealing a core. If that is the case I do not believe the sealant was doing anything more than holding the finder washers and bolts in place and any outdoor silicone would probably suffice. I have taken off many of these bolster bolts and that is all I could see that they were doing - besides making it hard for me to remove them. Could probably use nylon locking nuts but that would probably have been more expensive.

-Kevin

Thanks for the response.

There isn't a transom locker on this vintage - it's a 1997 model and I forgot to include that in my original post. Below is a picture I copied off the web as my boat is still in storage. The support mounting bars circled in red are where the sealer was. It's possible they weren't into the core but it has been six months since I took the seat out and my memory is not what it used to be. LOL.

 

[KevinC]

Thanks for the response.

There isn't a transom locker on this vintage - it's a 1997 model and I forgot to include that in my original post. Below is a picture I copied off the web as my boat is still in storage. The support mounting bars circled in red are where the sealer was. It's possible they weren't into the core but it has been six months since I took the seat out and my memory is not what it used to be. LOL.
View attachment 123835

I would just use a BoatLife product like Life-Calk for that area - but you can probably use any good outdoor sealant from the big box stores. You are just sealing the screws.

-Kevin

 

[Halfhitch]

If the sealant you are talking about was still kinda pliable and gooey then it may have been a butyl product. An easy method of applying and storing leftovers is using the tape type where you peel off what you need then peel the backing off. Good stuff when mounting locations that don't have submersion or heavy spray.
https://www.amazon.com/Dicor-BT-183...locphy=9012325&hvtargid=pla-434600583579&th=1

 

[KHE]

I would just use a BoatLife product like Life-Calk for that area - but you can probably use any good outdoor sealant from the big box stores. You are just sealing the screws.

-Kevin

I bought a tube of Life-Calk from West Marine. The upholstery shop forgot about the seat back... they said they'd have it completed by the end of this week but I'll believe that when I see it. They are two months past due from the timing they quoted.

 

[Lazy Daze]

LifeCaulk is excellent stuff -- although as noted above, it sounds more like you were originally referring to butyl rubber... which is REALLY good... but also not necessary in this case. One thing to note about LC... it gets EVERYWHERE... and even, like magic, places that were nowhere near where you were working. Use it sparingly and mask off areas.

For reference, butyl rubber is generally considered the gold standard as a bedding compound... for stanchion plates (which this case is), cleats, deck hardware, etc. But again, in this case, just about anything will work fine. Don't forget a little dab under the head of the bolt.

 

[KHE]

LifeCaulk is excellent stuff -- although as noted above, it sounds more like you were originally referring to butyl rubber... which is REALLY good... but also not necessary in this case. One thing to note about LC... it gets EVERYWHERE... and even, like magic, places that were nowhere near where you were working. Use it sparingly and mask off areas.

For reference, butyl rubber is generally considered the gold standard as a bedding compound... for stanchion plates (which this case is), cleats, deck hardware, etc. But again, in this case, just about anything will work fine. Don't forget a little dab under the head of the bolt.

The Life-Calk sounds like Anti Seize's cousin... You get Anti Seize on you and before you know it, it's in your armpits...LOL.

I just bought the roll of buytl sealing tape compound that Halfhitch mentioned.

It looks like the procedure is to roll the tape to a round "log" and apply it to the area of the bolt that is under the stanchion (also under the bolt head), then install, tighten and remove the excess. One video showed the installer countersinking the holes in the fiberglass slightly so more surface contact area can be obtained. What about additionally applying a ring of sealant around the bolt on the inside prior to installing the backing washer and nut?

 

[KHE]

I used the butyl tape and took the Life Calk back - I am glad I did. The maneuvering of the seatback to align it in place would have made a huge mess with the Life Calk. The excess butyl compound was easily removed after the seat back stanchions were bolted in place.