West System C205 Fast Hardener – 3.56 L (0.94 Gal)
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Fast-Cure Epoxy Hardener for Structural Marine Applications
The C205 Fast Hardener is designed for use with West System 105 Epoxy Resin in a 5:1 mix ratio, producing a rigid, high-strength, moisture-resistant bond with a short pot life. At 3.56 L (0.94 Gal), this large-format container is well-suited for boatbuilders, repair yards, and serious DIYers working on high-volume projects where fast turnaround between coats or laminations is a priority.
With a pot life of approximately 9–12 minutes at 22°C (72°F), C205 is the go-to hardener when working in cooler conditions or when a quick cure cycle is needed. It cures to a clear, hard finish compatible with most marine topcoats and finishes.
Key Features
- Fast cure cycle — pot life of 9–12 minutes at 22°C (72°F)
- 5:1 mix ratio with West System 105 Epoxy Resin
- Produces a rigid, high-strength, moisture-resistant solid
- Ideal for cooler working conditions or when fast recoat times are needed
- 3.56 L (0.94 Gal) bulk size — suited for large or ongoing projects
- Compatible with West System 300 Mini Pumps for accurate metering
Common Applications
- Fiberglass laminating and hull repairs
- Wood sheathing and encapsulation
- Structural bonding of marine components
- Coating and sealing in cooler shop or on-water conditions
Available Sizes
Also available in smaller formats: West System C205 Hardener, 208 ml (7 oz.) and West System C205 Hardener, 814 ml (27.5 oz.). For extended working time, consider the West System 206 Slow Hardener or the West System C209SC Extra Slow Hardener. Pair with West System C105B Resin – 3.74 L for a closely matched volume pairing.
Parts Desk Insights
Best Use Case: C205 is the right hardener for customers working in cooler temperatures (below 21°C / 70°F) or anyone who needs fast recoat times and doesn't require extended working time. It's the most commonly stocked hardener for general marine repair and laminating work. Steer customers toward the 206 Slow Hardener if they're working in warm conditions, doing large pours, or are newer to epoxy work and need more time to wet out fabric. The 3.56 L size pairs well with the C105B or C105C resin jugs for high-volume jobs. Remind customers to use the 300 Mini Pumps for accurate 5:1 metering — eyeballing the ratio is a common source of cure failures.
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.