Best bedding sealing product

[Disielcustoms]

Hi, question for the hive mind. I am re-bedding one of my chainplates. I have included picture of where the plate goes and the backing plate on the inside and where it penetrates the deck, where it is capped with a stainless cover. I am looking for the best sealing product or combination of products to use and best practice.


Thanks

[davil]

this sound interesting, have used for different on deck mounting and I like it

https://marinehowto.com/bed-it-tape/

[mikereed100]

For any hardware that is held in place with fasteners it is hard to beat butyl rubber. It stays flexible for decades and allows the fitting to be easily removed when the time comes. This is particularly important for a chainplate that will need to be inspected from time to time.

I would stay completely away from a polyurethane like 5200 for this reason. Likewise silicone RTV sealant. It works until it doesn't, then it is all but impossible to remove. I don't know why, but the previous owners of every boat I have ever bought used these almost exclusively!

[Disielcustoms]

thanks for the advice. I was thinking of butyl tape but not sure how to use it in this case since the chainplate is bolted to the bulkhead. As far as I know butyl tape is use between to parts been bolted together, at least that is what I have seen. In this case the gap around the plate as it penetrates the hull is what concerns me.

[sailormed]

Originally Posted by Disielcustoms

In this case the gap around the plate as it penetrates the hull is what concerns me.

When you install the chainplate I would use 2 pieces of plywood to seal the area around the chainplate on the ceiling. From the outside you can now push down and hard to completely fill the gap with butyl. Of course test for water tightness before capping.

[john61ct]

https://marinehowto.com/bed-it-tape/

https://www.google.com/search?q=buty...s&tbm=vid&sa=X

[SVTatia]

Do not use butyl tape - the rubber is good for compression uses only, and in this case you want a polyurethane compound that remains flexible as the chainplate moves ever so slightly under load and Sikaflex 241 is what I would recommend. Place a small piece of duck tape under the deck to stop overrun and stuff as much Sikaflex as you can, it will not adhere to the tape. Then if you wish, you can use a bit of butyl under thye SS plates around the chainplate.

[john61ct]

How do 241 and 291 compare?

[chowdan]

On my previous boat I used butyl jammed in the gap surrounding the chain plate and made sure to have enough protruding the deck surface so when I screwed the face plate down, itd squeeze it down and out and fill all possible gaps.

Never had a leak in that area for many years(next owner is sailing 5 years in without any leaks as well).

I am tainted due to my boat having a ton of 5200 and 4200 being used. I do not like these products one bit and will use them sparingly where butyl is not able to be used(fuel deck fill for example).

Anything else that is fastened mechanically, butyl is used.

As for chain plate sealants, you will want to only seal the hole, not anything else(ie between the knee and plate).

[Boulter]

Originally Posted by chowdan

On my previous boat I used butyl jammed in the gap surrounding the chain plate and made sure to have enough protruding the deck surface so when I screwed the face plate down, itd squeeze it down and out and fill all possible gaps.

Never had a leak in that area for many years(next owner is sailing 5 years in without any leaks as well).

I am tainted due to my boat having a ton of 5200 and 4200 being used. I do not like these products one bit and will use them sparingly where butyl is not able to be used(fuel deck fill for example).

Anything else that is fastened mechanically, butyl is used.

As for chain plate sealants, you will want to only seal the hole, not anything else(ie between the knee and plate).

Sealed my chainplates as above and very happy, that is they no longer leak. I agree100% with everything else too.