Chainplates

[LarryE-old]

What are other 7.9 owners using to seal the chainplates?
I have used 3M 5200 in the past and after 6 month have developed leaks. thinking of trying marine silicone.
Any feedback, good or bad.

[Rudeman]

3M 5200 is a hi-strength linear polyurathane sealant/adhesive. While you most certainly did not need to utilize the extreme-strength 5200, generally speaking linear polyurethane sealants are of excellent quality and should be up to the task.

I suspect your problem could be the results of poor surface preparation prior to application. Most silicone based sealants (what was likely used in the past) will leave a petroleum based residue behind. This residue tends to function like a "solvent" when other sealeants are used and will compromise the "seal" of the linear polyurethane sealant, and allow leakage.

Proper surface preapration generally involves removal of ALL of the former sealeant being used, use acetone to clean the area in question, afterwards sand the area throroughly to prep the new surface, use acetone again to re-clean the surface and re-seal.

Or you can stick with a silicone based sealant, although generally speaking the linear polyurathane sealants like 3M and Skiflex will perform better - they also have the advantages of curing with moisture, are sandable, and paintable.

Good Luck.

[akelly]

re: Chainplates:
We use Sikaflex-291 and it lasts for 2 seasons. We have best success when all the old sealant is removed (Sikaflex 291 comes off easily) and the mast is stepped. Tension up the shrouds. One guy holds the chainplate cover plate off the deck and the other guy on the caulk gun. It gets very messy doing it yourself! Put tape inside cabin so the sealant does not leak thru. We press the cover plate down but do not screw it to the deck - 4 less holes to leak. Good luck
Arlo Kallemeyn
Chili Pepper #501

[Tim Bosma]

Larry,
We redid our chain plates a year ago. We used 5200 and have had no leaks yet. Surface prep is most important as Rudy says. We lifted the plat cover, cleaned out all prior sealant and took up a micron or so of the gelcoat, then cleaned it all with acetone before rebedding. The 5200 oozed out around both the outer rim and the inner slot of the cover so we knew we had a good seal. We didn't clean up excess until it was set, then we just trimmed it up a little without disturbing the sealing surfaces.

[Sam Buschell]

I use 3M 101.
It is a sealant without the adhesive properties of 5200.
5200 has its place (toe rails, deck joint, etc) but I find the 101 is more flexible and much easier to take off and reseal which I do every other year.


http://products3.3m.com/catalog/us/en00 ... utput_html

[Guest]

I used 101 and have not had any problems. Like the rest stated surface prep. I you have had leaking make sure you check the balsa core for water. We had water intrusion in there and I doug it all out with chisles and filled them in with epoxy before I reseated them.