Sika Sikaflex-221 - White - Multi-Purpose Polyurethane sealant/Adhesive - Creates Permanent Elastic Seal - Sandable/paintable - Non-Corrosive - 10.1 fl oz (Pack of 24)

I used Sikaflex to adhere a roof wing to the back windshield of my car, and I’m seriously impressed with how well it worked. The bond is incredibly strong and feels permanent once cured. I let it set for about 24 hours before driving, and even after months of highway speeds and temperature changes, the wing hasn’t budged at all. The application was pretty straightforward, it has a thick, tacky consistency that gives you enough working time to position everything correctly before it starts to set. I’d recommend taping or clamping the part in place while it cures, because it does take a while to fully harden. Once cured, it’s flexible enough to handle vibration and movement, which is great for automotive use. One thing to note: this stuff is messy. It’s sticky, and once it gets on your hands or paint, it’s not easy to remove. Wear gloves, mask off surrounding areas, and have some cleaner or mineral spirits ready. Overall, Sikaflex delivered exactly what I needed, a strong, weatherproof, and vibration resistant bond that’s holding my roof wing securely in place. It’s not the cheapest adhesive, but it’s worth it for the strength and reliability.

Great sealant for my box truck build, strong but flexible

This sealant worked perfect on my Toyota Tacoma to fill the bed-line gaps. It is crack resistant I bought extra in case I ran out during the project but was able to get my money worth during the project. Dried quickly and looks like a factory finish.

Oh this is the stuff you want working on bare metal airstream! Works very well on vertical walls, you can probably use it on the roof too but this isnt self leveling. Used it to seal all the marker lights, windows, doors, etc.

This product is not water solvable and sticky as heck. Requires a bit of caulking skill but really bonds and is somewhat sandals too.

I work with this sealant, it's spectacular

This stuff is fantastic, especially for bonding hard to glue plastics. Be sure to wear gloves - it is very durable on skin!

Sikaflex 221 exceeded my expectations. It’s incredibly versatile, adheres to a wide range of materials, and cures to a strong, flexible seal that holds up under tough conditions. I used it for sealing my little project little tikes and it performed flawlessly—no leaks, no cracks, and it’s weather-resistant. Application was smooth and cleanup was easy. Whether you're working on automotive, construction, or DIY projects, this is a must-have product. Highly recommended!

Very good

Buen sellador excelente para celular y buena. Marca

Great brand always works

Good quality

I needed some good adhesive to attach solar panels to my camper and a lot of places recommended this stuff so I decided to give it a shot. It applies just like any other adhesives, pretty straight forward, and when used as instructed it creates a very nice bond between two materials. I was wary at first driving down the highway on first test run paranoid the wind was going to rip them off, and after a couple summers with highway driving, I am now confident in the quality of the item. It does what it is intended for. Would, and have, bought this again.