Sikaflex-291 Marine Sealant Black 300mL Cartridge (SIK-291BLK-300ML)
Free returns on all eligible orders
You have 30 days to request a return. All sale items are final sale.
Sikaflex-291 is the marine industry’s benchmark one-component polyurethane sealant and adhesive — trusted by boatbuilders, yards, and owners worldwide for its outstanding adhesion, flexibility, and long-term durability in the harshest marine environments. This 300 mL cartridge in Black is ready to use with a standard caulking gun for precise, controlled application.
Features
- One-component moisture-curing polyurethane — no mixing required
- Excellent adhesion to fibreglass, GRP, wood, metals, and most marine substrates
- Permanently flexible after cure — accommodates structural movement and vibration without cracking
- Waterproof and resistant to seawater, UV, and weathering
- Suitable for above and below waterline applications
- Paintable after full cure
- Black colour — ideal for hull-to-deck joints, portlights, hatches, and dark trim
- 300 mL cartridge format for use with standard caulking gun
Specifications
- SKU: SIK-291BLK-300ML
- Brand: Sikaflex (Sika)
- Product: Sikaflex-291
- Colour: Black
- Volume: 300 mL
- Format: Cartridge (caulking gun application)
- Chemistry: One-component polyurethane (1C-PUR)
- Cure Type: Moisture-curing
- Application Temperature: +5°C to +40°C
- Skin-Over Time: Approx. 60 minutes at 23°C / 50% RH
- Full Cure: Approx. 3–7 days depending on conditions
Applications
Sikaflex-291 is the go-to sealant for a wide range of marine sealing and bonding tasks: hull-to-deck joints, portlight and hatch bedding, through-hull fittings, deck hardware bedding, keel bolt sealing, teak deck seams, and general above and below waterline sealing. Its flexibility and adhesion make it equally suitable for new construction and repair work.
Surface must be clean, dry, and free of grease before application. Use Sika Primer or Sika Cleaner as recommended for optimal adhesion on difficult substrates. Mask adjacent surfaces before applying. Tool within the skin-over time window. Not suitable for use on polypropylene, polyethylene, or Teflon surfaces without appropriate primer.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 3–4 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.