3M FC4000 UV Marine Adhesive/Sealant, 10 oz Cartridge

I recently refinished a sailboat using 4000UV for most deck fittings, and while I don't yet have any leaks (4yrs later), the caulk that is exposed to the elements is falling into little pieces. This makes me nervous as I would REALLY not like to remove the toe rail and all other hardware if this fails. The Butyl Tape that was original to the boat lasted almost 40years. It remains to be seen how long this 4000UV will last. I would definitely not recommend this marine sealant. I'm surprised 3M is still selling this product after many reports of failure. Considering how much was at stake with the compound I used, should have gone with a trusted product like 4200. Wondering if there will be a class action lawsuit.

I used this produce to seal/bed a new boat cleat. It never cured altho conditions were ideal. It was a complete failure. Produce was straight off the shelf.

The product did not come with a nozzle/tip! No cap, no nozzle, no tip! Product is probably good but cannot apply it without a tip!

You see a lot of negative reviews on this product after people don't follow directions applying it. First off, it's meant to be flexible, secondly it needs time to cure. If you can figure out how to apply it you can figure out how to read the instructions; clean and prep your surface before applying.

Dug out all caulk on our boat two years ago and used 4000uv as a replacement, huge mistake. After pulling the boat this year noticed caulk is turning into chalk. Not looking forward to another winter of redoing this because of a sub par product.