

🔗 Seal it once, seal it right — the pro’s choice for lasting bonds!
Sikaflex-221 is a professional-grade, black polyurethane sealant and adhesive offering a 10.1 fl oz cartridge for easy, precise application. It forms permanent, elastic bonds on metals, plastics, ceramics, and more, curing fully in 3 hours. Waterproof and resistant to aging, seawater, and chemicals, it’s NSF-approved for safe use in drinking water and food production. Ideal for internal seals and automotive or industrial projects requiring durable, flexible adhesion.















| ASIN | B00NW5LWHA |
| Best Sellers Rank | #1,040 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #3 in Polyurethane Adhesives |
| Brand Name | SIKA |
| Color | Black |
| Customer Reviews | 4.6 4.6 out of 5 stars (2,857) |
| Full Cure Time | 3 Hours |
| Included Components | AP Products 017-90893 Sikaflex-221, Black |
| Item Form | Paste |
| Item Type Name | AP Products 017-90893 Sikaflex-221, Black |
| Item Weight | 10.1 Ounces |
| Liquid Volume | 10.1 Fluid Ounces |
| Manufacturer | SIKA |
| Material Type | Polyurethane |
| Surface Recommendation | Metal, Wood, Glass |
| Unit Count | 10.1 Fluid Ounces |
| Water Resistance Level | Waterproof |
O**A
Perfect for automotive use
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.
X**D
Nice hold, yet has some flex
Great sealant for my box truck build, strong but flexible
R**.
Strong, Reliable, and Easy to Use.
Sikaflex 221 was easy to work with and performed well in my project. It adhered strongly, cured into a solid bond, and left a clean finish. So far, it has held up well and given me confidence in the result, sealing even with heavy rains.
A**M
Works great in my metal building
This stuff is phenomenal and a Saving Grace it cures very hard but yet subtle
D**H
Dries fast
Excellent caulking
P**H
Very strong grip
I used this to attach my solar panels to the fiberglass roof of my van. Being a hero i also put one 1/2 inch screw in each. I let it sit overnight and didn't leave town for three days. They haven't moved a millimeter
M**T
Tight bond
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.
I**S
Great stuff for RV
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.
H**M
Very good
A**X
Buen sellador excelente para celular y buena. Marca
K**Y
Great brand always works
A**R
Good quality
T**S
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.
TrustPilot
3 周前
2 周前