Sudbury 300 Marine Sealant – White, 10 oz. Cartridge
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Sudbury 300 – Marine Sealant, White, 10 oz. Cartridge
Sudbury 300 is a one-component marine sealant with fast skinning (approximately 10 minutes) and a full cure time of 1–7 days. It delivers superior strength, adhesion, and elongation across a wide temperature range, making it suitable for both above- and below-waterline applications. The white colour suits hull seams, deck hardware, and white-painted surfaces where a clean, finished appearance matters.
Key Features
- One-component — no mixing required
- Fast skinning: approximately 10 minutes
- Full cure: 1–7 days
- Cures in temperatures from -20°F to +120°F (-29°C to +49°C)
- Excellent flexibility, compression, and elongation
- Suitable for above- and below-waterline applications
- Wet-sandable and paintable after cure
- Adheres to fibreglass, wood, metal, glass, Plexiglas, Lexan, and most plastics
- Clean up with mineral spirits
- Not recommended for wood deck seams
- White colour — suits hull seams and white deck surfaces
Compatible Applications
- Hull seams and below-waterline sealing
- Deck hardware bedding on white or light-coloured surfaces
- Through-hull fittings and port lights
- Fibreglass, wood, and metal joint sealing
- Glass and Lexan/Plexiglas bonding and sealing
- General above- and below-waterline maintenance sealing
Parts Desk Insights
The Sudbury 300 is a versatile, heavy-duty sealant that works above and below the waterline — a broader range than many polyurethane sealants that are rated above-waterline only. The wide cure temperature range makes it a practical choice for cold-weather maintenance work. If you need the same formula in a different colour, the Sudbury 302 (Black, 10 oz.) and Sudbury 301 (Clear, 10 oz.) are the cartridge siblings. For smaller tube-format jobs, the Sudbury 320 (White, 3 oz. tube), Sudbury 322 (Black, 3 oz. tube), and Sudbury 321X (Clear, 3 oz. tube) are available. Note: not recommended for wood deck seams.
Related Products
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.