Caulking windshield to deck

Nmor830

Member
Sep 12, 2016
90
Channel Islands
Boat Info
2008 340 Sundancer
Engines
8.1l Mercruisers
2008 340 Sundancer caulking between the deck and the windshield is crumbling. In researching different products 3m and others it seems there are a lot of mixed reviews. Wondering if anyone has done this and what was used and how well it is holding up.
thanks,
nick
 
I like 3M products never seen it crumble, as long as it's prepped properly.
Could you be dealing with an additional, owner applied caulk that was placed over a waxed or dirty gel-coat??
 
Clean with brush to remove the old caulk. 3M 4200 is available in calking tubes witch allows greater control when applying. I masked both SS on frame and the gel with 1/2" vinyl auto paint tape. Make certain to clean the area well with 3M Shape shooter . It will remove the wax and dirt.
 
I like 3M products never seen it crumble, as long as it's prepped properly.
Could you be dealing with an additional, owner applied caulk that was placed over a waxed or dirty gel-coat??

I believe this may be the original caulking material used by SR but can't be 100 % sure. Noticing all the sealed joints are looking old and cracking. The boat spent it's life in So. Calf. where it takes a good bit of UV abuse. Seems the 3M 4000 4200 is the material of choice which is probable what I'll use.
thanks,
Nick
 
I used BoatLife Life Seal in white to do my windshield/deck joint two seasons ago... working great so far and still white. I used a cheap plastic caulk remover tool and plastic razor blades from HD to scrape out the dried caulk. Painters tape for cleaner edges would have been a good plan, but I didn't think of it.

Also used LifeSeal to re-attach the vent covers and that held up for 4 seasons. The material was still white and flexible, just had to be redone because fenders occasionally push up against the covers when rafted with taller boats. It eventually starts to the covers loose at the aft corner.


http://www.boatlife.com/lifeseal-sealant-cartridges/
Manufacturer's site, but available at WM and many other places.
 
Last edited:
The OEM's are using Sikasil-N Plus which is what I used to have the 400DA completely caulked.
I had a long discussion with the Sika technical representative on what to use and they specified the Sikasil-N Plus; It went in and filled very smoothly and tooled out perfectly.
I would not use 3M 4000, 4200, or 5000 as these are adhesives and not joint sealants. You will not be able to "tool" the joint and make it look good at all if you use these 3M products.
 

Forum statistics

Threads
113,163
Messages
1,427,598
Members
61,072
Latest member
BoatUtah12
Back
Top