

🌊 Seal the deal with speed and strength—your boat’s best defense against the elements!
Sikaflex-291 is a professional-grade, fast-curing polyurethane marine adhesive and sealant designed for superior bonding and sealing on boats. It offers excellent adhesion to multiple surfaces including gelcoat, fiberglass, metal, and wood, while providing durable resistance to fresh and saltwater, chemicals, and oils. Its elastic, vibration-resistant formula ensures long-lasting seals above and below the waterline. NSF and USDA approvals make it safe for incidental food contact, making it a trusted choice for marine professionals and enthusiasts alike.















| ASIN | B01GPIXX5Y |
| Best Sellers Rank | #7,583 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #44 in Silicone Adhesives #57 in Adhesive Caulk #107 in Industrial Sealants |
| Brand | SIKA |
| Color | White |
| Date First Available | June 8, 2005 |
| Is Discontinued By Manufacturer | No |
| Item Form | Gel |
| Item Package Quantity | 1 |
| Item Volume | 10.1 Fluid Ounces |
| Item Weight | 10.6 ounces |
| Item model number | 90919 |
| Manufacturer | Sika USA |
| Material | 1-C polyurethane |
| Package Information | Cartridge |
| Product Dimensions | 11.5 x 2 x 11.5 inches |
| UPC | 033886005258 |
| Unit Count | 10.1 Fluid Ounces |
| Viscosity | Moderate |
| Viscosity Level | Medium |
| Water Resistance Level | Water Resistant |
J**F
Holds well, good gap filler.
Used this to fill the seam between the hull and deck. Used an electric calking gun allowing for controlled flow into the seams which were 22ft runs from stern to bow. took two tubes of Silkaflex. While fresh it was easy to use a scraper to push this material deeper into the seam and simple to remove excess leaving a smooth seam level with the deck. It took several days to harden to my satisfaction and in the meantime collected a layer of dust onto its surface. Once painted there is a subtle but clear discoloration showing through the paint. It's a good product but as this was a restoration job on a classic wooden boat I think epoxy would have been a better choice. But, no complaints with how this material works and I'm sure it will hold up for some time as the hull and deck flex a bit with movement and with the natural swelling and shrinking inherent in wood.
D**T
Silkaflex Boat, RV, General use.
This is really good RTV! I didn't know Silksflex existed until I had to change out a pair of jet drives on a Zodiac Hurricane. Silksflex RTV was the recommended by the OEM manufacturer. I use Silkaflex on Motorhomes, trucks and around my house. Very strong and flexible and seawater resistant.
L**A
Would buy again
Great product..worked well..
G**T
All good
Great product great service
M**R
Strong
Worked well, though it dries a bit off white
A**H
Works great!
I forget why I bought this - car repair? - but it worked great!
K**.
Bought white but came black
Well it pays to pay attention. Bought a tube in October and finally getting around to using it today, Jan 30. Hurricanes slowed me down. Took all the old caulk out of the funnels, taped it off and went to start to re-caulk and lo and behold it’s black! The label pictured does say white but after looking at the tube itself near the label does say black. Now I’ve had to reorder and pay the expedited shipping since it took me 2 hours to tape off the gunnels not to mention the time it took to remove the old stuff and don’t want to leave tape on the fiberglass in the sun to long. Way to go Amazon and Sika!
N**O
EXCELENT
super good product
J**Y
Expensive for what size. There are other silicones on the market to look into before purchasing Sika Sikaflex 201.
B**R
I bought this Sika 291 to repair an aluminum canoe. This marine urethane is basically the same thing that SportsPal sells in their repair kit. I haven't used it yet but based on other reviews it will be fine for the repair I set out to accomplish Regarding other reviewers stating they received out of date or wrong colour product, I ordered black and got black and the use by date was 9 months into the future (July 2025) beyond my purchase date Nov/2024.
W**L
As advertised look forward to using in the spring.
A**R
It has worked well but they sent me the wrong colour and hubby did not read it before opening it.
Y**B
Received very old, dry product with expiry date in only a few months. Typically these have several years of shelf life left.
Trustpilot
1 day ago
4 days ago