Sikaflex1A Polyurethane Premium Grade High Performance Elastomeric Sealant, 10.1 fl oz Capacity, Black

We started using this for horizontal gap filling between door/window sill pans and the actual sills. The viscosity is awesome as it works its way into the tiny gaps and levels itself. No other caulk we've found works as well as this to prevent water penetration.

I used this to seal the base of my lathe against coolant leaks. Would recommend.

The viscosity of this black goo has a strange characteristic: as you squeeze out a long bead along the edge of my sunroof molding and glass, the thick bead CANNOT be re-brushed or smoothed out! It must be applied in L-O-N-G, steady, smooth strokes. Only way to re-coat for more thickness is to wait 2-3 days to dry, then, carefully use an ultra sharp razor held flat to a level plane and pull the blade slowly across the unwanted higher ridges of dried black rubber.I can see that this process will need to be repeated periodically, depending on how long the weather elements (blazing hot sun in North Carolina) will be blocked by this rubber seal.

Wverything that i was told about this product is true! Great for wayer proofing and fixing leaks on drain lines, gutters, windows, skylights, ponds and many other applications.

I've been using 1a for years to seal concrete water tanks. Never had it leak or break seal. Great for other materials too. Professional quality stuff.

Product is great the packaging from Amazon is bad. They crammed 3 tubes in a box too small and broke the tips so the sealant was leaking from the tubes. Had to send them all back and just a waste of time. Lowes carries the sealant for the same price so a better option.

Not impressed with the actual product…

Used rubber 4'X6' rubber flooring for home gym. This sealant worked great to seal cracks and smooth out uneveness of height of adjacent mats. Room looks like one large, smooth custom fitted flooring. Easy to apply and work with.