We have standardized on 3M 4200. we have some that is 3 years old. Eventually you will have to recaulk this and also the 4000. No caulk will last forever. It is part of the maintenance game onboard. We like the fast cure and it skins over quickly and we can paint over it. Also when we have a little caulk left over in the 10 oz cartridge, 5200, 4200, Teak Deck Cal it all goes in the freezer and you can use it at a later date. You do not have to discard what you didn't use. Safe Cruising. Bob Kovach KJ4UGE Chief Engr Bob, Onboard ALLEZ! (MT50) Gold Looper 5-2-16 Lying Ft Pierce, FL MTOA 2631, AGLCA1979, USCG-ARC-KJ4UGE, USCG-CWOA, USPS Charleston, S.C., WRCC, DFC