Rub Rail and 3M 4200

[SK]

I replaced the caulk around the top of my rub rail last year. Factory had done a real lousy and messy job of installing it in the first place. The rub rail in white on the outside with a stainless section in the middle with screws every 8 inches or so. Well....
The white 3M 4200 caulk is now turning yellow. It has faded so much that it is seriously noticable against the white boat and white plastic on the rub rail.
Did I use the wrong caulk? Should I just use white silicone?
The boat is always covered with a mooring cover and is under a covered dock when not in use.
What's your thoughts.

 

[BobV1]

The 3M 4200 doesn't have UV stabilizers in the formula. Therefore, it would not be a good choice for sealing a rub rail.

I used 3M 4000UV last year to seal my rub rail. Although it didn't turn yellow, it did not hold up to the UV radiation. It began to chalk. Next year, I plan to use a silicone.

Bob

 

[divedaddy]

3M 4200 has fairly poor color stability in UV exposure. For that kind of adhesive/caulk 4000 UV would be the better choice. But for rub rail sealing, the even better choice would be a silicone or a modified (silylated) polyurethane like Life Seal (NOT Life Caulk) or Bostik 960 SR. I like like Seal and it's easy to find.