Caulk for Gunwales and Rub Rails

Repair or modification of Boston Whaler boats, their engines, trailers, and gear
Vance's Revenge
Posts: 108
Joined: Wed Nov 25, 2015 2:37 am
Location: Northern California

Caulk for Gunwales and Rub Rails

Postby Vance's Revenge » Thu May 19, 2022 1:39 pm

For maintenance I'm adding a couple coats of varnish to the gunwales on my 1980 Revenge 22. When I originally restored them in 2019 (three years ago) I used 3M4200 Fast Cure adhesive sealer on the rub rails, the seams, and the fuel fill because I had some left over from my restoration. The 3M4200FC Fast Cure shrank over time, and I don't want to use it again.

From people that have used other products themselves and had success: give me a recommendation for a new caulk or sealer to use on the gunwales and rub rails. The caulk to be recommended must be able to tolerate occasional contact with gasoline fuel.

I don't want manufacturer's recommendations repeated as a suggestion.

Thank you in advance.

Vance

User avatar
Phil T
Posts: 2129
Joined: Thu Oct 22, 2015 6:08 pm
Location: Was Maine. Temporarily Kentucky

Re: Caulk for Gunwales/Rub rails

Postby Phil T » Thu May 19, 2022 3:29 pm

Boat Life's Life Caulk in white is the top recommendation. With age it turns slightly tan, blending in with the gelcoat.

Personally, I went with OSI Quad #450 and am very pleased with it.

While Lowes carries it online, I ordered mine from Amazon.

https://www.amazon.com/OSI-Sealant-10-Fluid-Cartridge-1636981/dp/B013LS91Q6

Matching_Caulk_OSI_Quad_450.jpeg
Fig. 1. Tube of caulk.
Matching_Caulk_OSI_Quad_450.jpeg (33.32 KiB) Viewed 135 times
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003

Vance's Revenge
Posts: 108
Joined: Wed Nov 25, 2015 2:37 am
Location: Northern California

Re: Caulk for Gunwales/Rub rails

Postby Vance's Revenge » Thu May 19, 2022 8:19 pm

Thanks Phil,

I saw that guys were using OSI Quad #450 on their floor sections such as the fuel tank cover. If I ever have to re-do the floor sections I will defintely use the OSI Quad #450.

I had not seen where anyone used OSI Quad #450 on the gunwales. OSI Quad #450 should work great with fiberglass gunwales . I think white would look better on the varnished teak gunwale to rub rail seam.

I also need a sealant that is fairly easy to remove. I had a heck of a time removing the stainless steel side rail fittings without the 3M 4200 Fast Cure pulling up my clear on the Teak gunwale while removing it. I had one tear in the clear varnish but fortunately it didn't pull it up far enough outside the fitting to see the tear when I get it back together and sealed.

Vance

User avatar
Phil T
Posts: 2129
Joined: Thu Oct 22, 2015 6:08 pm
Location: Was Maine. Temporarily Kentucky

Re: Caulk for Gunwales and Rub Rails

Postby Phil T » Fri May 20, 2022 9:58 am

To remove a product like 4200 or its sister, 5200 will be a bear since they are an adhesive first, then a sealant.
The marketing on this type of product is nonsensical.

There really isn't a decent reason to use 4200/5200 on a boat unless you are doing structural work.
1992 Outrage 17
2019 E-TEC 90
2018 LoadRite 18280096VT
Member since 2003