Chainplate and stanchion sealant

[Bob K]

I am ready to reseal a leaking chainplate - I resealed it with Lifecaulk polysulfide caulk two years ago, and it is now starting to leak a bit - it looks like the sealant did not bond well to the stainless chainplate - maybe I didn't clean all the old silicone off good enough.  Anyway, I am looking for a better sealant  - I heard there is a new type sealant that is similar to polysulfide but it is UV resistant and does not discolor.  I didn't see it during my last to BoatUS, but I was in a hurry, and maybe I missed it.  Can anyone tell me what this new stuff is called?  (or maybe I just dreamed this stuff up one cold winter night???)

Thanks,
Bob 

[Stu Jackson]

Bob, there's no magic to this.  There are the basic materials that are in tubes.  Most of the answers could well be anyone's personal urban myths.
I swear by simple silicone, and have repaired and / or replaced most everything on our boat in the past 9 years.

I keep up with new things, rarely have had to go back to redo anything (except the ever-recurring chainplates) I like it.

Many have expressed their preferences for other materials.

All I can categorically state, that's my own personal opinion, is:  "There is NO place aboard a boat for 5200 other than a hull to deck joint."

[DougP]

I agree that there's few places for 5200, but I also don't care for silicone.
Silicone is great stuff, but it can only be mechanically removed. In other words: No 3M adhesive remover, acetone, or solvent will remove it. Makes it hard to remove it all.

[David Sanner]

I'm also a fan of silicon for use where it will be under compression
and needs flexibility.    The excess silicon can be easy to cleanup if
you wait a little time for it to get stiff but not hard.   But once it's
hard I guess it needs to be scraped off.

I'm surprised your polysulfide re-bedding is already leaking.

There have been a lot of write-ups about re-bedding the
chainplates (a new very thorough one on the way) but I've
had good luck re-bedding with silicon.

Reminder: One thing that's common to do is make a gasket
out of silicon.   (or whatever caulk you are using)

It's simply, just use loads of silicon on the bottom plate, in
the hole in the deck and on the top plate.  Before the getting
anywhere near a final tightening of the bolts let the silicon dry
for a day or two.  Then hold the bolt still while the nut is
tightened.  Instant gaskets and a good seal around the bolt.

[Mike and Joanne Stimmler]

I've heard on another 3m product besides 5200, I think it's 4200 on something similar. Could this be the polysulfide product you are talking about?

Mike

[Stu Jackson]

Mike, 4200 is an adhesive, like 5200, but with somewhat less "grip," thus, supposedly, easier to remove.

For a description of the materials, one source is: http://www.boatus.com/boattech/casey/35.htm

The Don Casey Library under Resources on the home page of BoatUS also has Casey's description of how to rebed deck hardware.  If you finish the article linked above, click on the DC Library and find that one, too.

West Marine Advisors and other sources also are good at describing the different basic materials.

We've had no trouble removing old silicone:  a wire brush and some soap and water have usually been all that's required.

[Footloose]

Bob,

I have had good success with LifeCaulk.  I use the primer on wood and metal surfaces.  I also wait 3-4 days before doing the final snugging of the bolts.  This stuff takes about a week to dry.

[Bob K]

I was not aware of a primer for Lifecaulk.  My bond failed at the chainplate, so that may be helpful for me.  I've used Lifecaulk for years with varying degrees of success in durability.  Is the primer available at WM? 

[Footloose]

Bob,

WM has the primer but it had to be ordered.  Whether or not it does anything long term, ie 8-10 years, is still in the experimental stage.

[Roger Blake]

Stu---Is there a particular silicone product you prefer and could recommend? Chainplates are on my list of projects this season...right after a Y valve for the holding tank, cleaning the heat exchanger (and replacing end gaskets and zinc), replacing an air conditioner hose. fixing 2 port leaks, wax, paint, hmmm...the list goes on. But the chainplates are a must fix this season...sooner than later. Oh yea...somewhere in there in plan to do some sailing.  Thanks.

[Stu Jackson]

I've used a variety of them, all manufacturers / brands, including from Ace Hardware.  Doesn't seem to matter, WM is usually the least expensive, when on saile - just got a small tube and caulking gun cannister for half price.

[mainesail]

I like Sikaflex 291 LOT. I have no idea what the LOT means but the stuff is great. It's a polyurethane & bonds similarly to 4000 UV or 4200 but retains 700% elongation before break where 5200 and 4200 are roughly 300 to 350% elongation at break. Most of the top quality boat yards here in Maine use Sikaflex..

[Steve Hansen]

I think I am going to try Boat Life "Life seal" Which is a combination silicone and polyurethane. Found this write up on the C36 site with pictures included for rebedding chain plates. I think it gives a pretty good description of the process. Does not show rebedding the bolts.

Steve

[Steve Hansen]

Sorry, forgot to put this in the previous post re: Rebedding chainplate.

http://www.catalina36.org/articles/maintenance/Chainplates.htm

Steve