Sikaflex-291 LOT, White, Marine Adhesive and sealant, General All-Purpose PU Adhesive with Long Open time, 10.1 fl. oz

I used this to attach a heavy duty rub rail on my old BW Outrage (belt and suspenders approach, I didn't trust that the screws that came with the rub rail would work). It's been six months since I did the work and it seems to be holding well. Cures somewhat quickly which makes it tricky to use on a large area in summer heat. I'd use it again before the #M product.

Works good.

I used it to seal between the body and the bottom pan of a 1970s VW Beetle I'm rebuilding. It'll take me months to find if the seal provided by this product is durable. But for now, it looks encouraging. Also, it is rated for "below the waterline", and that should be more than sufficient overkill for a Volkswagen. As I had to apply the sealant from below the car, it dripped a little bit but not badly. The product flows into place readily and can be smoothed, like caulk, with a gloved (!!!) finger. Go without gloves and have a very messy clean-up coming. The product dries to a deep glossy black. As it is paintable, I plan to spray the bottom of the car with undercoating for protection. The seals cured overnight and look confidence-inspiring.

Grabbed some rubber to make a cover for the saildrive port on my sailboat; it keeps barnacles out. I wasn't expecting this to hold at all for months underwater and under sail. Still there six months later. I am amazed.

Great for the boat seams

As other’s indicated, it sticks to everything. I taped the caulk lines and waited about 45 minutes before pulling tape. Could have waited another 15 to 30 minutes. Takes a while to dry. Once dry, it is solid and flexible with great adhesion

Silkaflex is great. I had it on my engine bolts for about couple months. I had the need to take it off and was amazed that it works well. Now, this is what I use on most areas which need caulking.

Seals out water well.