CONTINUOUSWAVE

I have a 1999 Whaler Outrage II with a major hatch in the deck, covering the large center fuel tank. This hatch was sealed with what appears to be a silicone-based sealant (from what I can determine by its characteristics upon removal). It's being replaced because after many years it has become detached from the sides of the joint, through shrinkage or stress.

I have heard all the horror stories about the problems silicone sealants cause regarding preventing any other sealants from adhering properly. At the same time 3M tells me 4000UV is a superior product to their marine silicone caulk, so it's the preferable choice, if I can make it work.

I have razored-out the caulk, done an acetone scrub down, sanded the entire joint, and re-washed with acetone. I am at a loss about any additional preparation to do to maximize the chance that the 4000UV will [adhere].

Give me a suggestion comment about using the 4000UV instead of going again with silicone, since that was already in the joint originally.

Thanks.

Just use Boat Life's Life Caulk. It is a polysulfide based marine sealant.

Tape off both sides of the seam, lay in a bead, wipe with your finger. Let it skin over (~3 hrs), then pull the tape.