Type of sealant to use

[Broaders]

Good day all,
I'm getting ready to re-seal around my boat, around windows (porthole ),I don't want to remove the porthole as they are very hard to find if I brake one.
I also want to seal where the top of my boat is attached to the hull, again I'm not planning on removing the screws and trim that holds the top and bottom together, just going to run a bead above and below this piece.
Just wondering what most people use. I have read up on some products like 3M 5200, and they say it very hard to remove once applied, also here in Newfoundland it cost $62.00 a tube tax in.
Any input in to best practices, materials and how this should be done would be greatly appreciated.
Cheers
safe sailing

 

[alldodge]

Suggest 3M 4000

 

[Scott Danforth]

3M UV4000 or lifecaulk or Sika

Do these port lights match?

PORTLIGHT ASSY 01 7/8" SPIGOT (9700XX)

97001C Product Drawing 97002C-2 Product Drawing

shopggschmitt.com

 

[Grub54891]

Attempting to seal them areas from the outside edges don't work. All it does is make a mess. Then when you decide to do it right by removing them, you have to clean up the mess. I've never broke a window, or portlight removing them. Just proceed carefully, heat the area slowly with a heatgun and gently get a thin scraper made of plastic under and edge and work your way around. Not to hot, as it could wreck the gelcoat.

 

[Broaders]

Attempting to seal them areas from the outside edges don't work. All it does is make a mess. Then when you decide to do it right by removing them, you have to clean up the mess. I've never broke a window, or portlight removing them. Just proceed carefully, heat the area slowly with a heatgun and gently get a thin scraper made of plastic under and edge and work your way around. Not to hot, as it could wreck the gelcoat.

Thank you so much I will give that a try and see how it works out, hopefully good.

 

[dingbat]

Trying to seal a leaking hull seam by caulking the rub rail is an effort in futility.

You are far better off removing the rub rail and tackling the joint head on. I used 5200 for it adhesion properties, but you can use just about anything to seal the joint since the joint is held together with screws

 

[909]

Sika is half the price of 3M

 

[Chris1956]

Gee, what about clear silicone caulk. It is used on my Anderson windows, and lasts decades or longer. It is less than $10 / tube.

 

[dingbat]

Gee, what about clear silicone caulk. It is used on my Anderson windows, and lasts decades or longer. It is less than $10 / tube.

Had to caulk all my deck seams and windows.

Called my manufacturer to see what they used…..GE Silicon II in Almond was their answer

 

[Grub54891]

Dont use regular silicone. It’s close to impossible to clean up if you need to take it apart later, and it doesn’t seal well with gelcoat.

 

[Chris1956]

Gee, I use silicone caulk to seal the cover over the fuel tank. No issues sticking to gelcoat there. I used it to install new scuppers. No leaks there either. It is tough to get off if you want to, though. There are silicone-off products that work a little.

 

[dingbat]

Dont use regular silicone. It’s close to impossible to clean up if you need to take it apart later, and it doesn’t seal well with gelcoat.

You hear people say that all the time but that has not been my experience.

Used Silicon II to caulk two, large fiberglass panels down the middle of the cockpit…..twice. Don’t ask…lol

Cut most old material away with razor blade. Alcohol cuts the remaining residue. Doesn’t take long to clean surface well enough to apply new material.

Applies well…..lined both sides of the joint (~3/8”) with painters tape. Used a wet finger to smooth and contour the surface. Surprised how well it came out.

That was 10 years ago. Still looks good today.

 

[Grub54891]

I get that people like the regular silicone, At the shop the paint dept removes some of the hardware for repairs and such. I'm usually involved in helping. I just don't like messing with it. 4200, lifeseal, 400, are ok to get off. Don't use 5200 unless it's never coming apart again!