West System 655-42216 Barrier Coat Additive
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You have 30 days to request a return. All sale items are final sale.
West System 655-42216 Barrier Coat Additive
Protect your hull from the inside out. The West System Barrier Coat Additive is a proprietary blend mixed directly into epoxy resin and hardener to significantly improve the cured epoxy's ability to resist moisture penetration — one of the leading causes of gelcoat blistering on fibreglass boats.
When added to a mixed epoxy system such as West System C105A Epoxy Resin, this additive transforms standard epoxy into a high-performance barrier coating. It also increases the abrasion resistance of the cured film, making it well-suited for below-the-waterline applications where the hull faces constant exposure to water and mechanical wear.
Key Features
- Improves moisture-exclusion effectiveness of cured epoxy
- Helps prevent gelcoat blistering on fibreglass hulls
- Increases abrasion resistance of the cured epoxy film
- Mixes directly into the epoxy system — no separate application step
- Ideal for below-the-waterline barrier coat systems
Parts Desk Insights
Best Use Case: Recommend this additive to customers who are repairing or re-coating a fibreglass hull, particularly those dealing with existing osmotic blistering or wanting to prevent it on a new or stripped hull. It's most effective when applied as part of a multi-coat barrier coat system over bare fibreglass, before antifouling paint. Pair with the appropriate West System C105A Epoxy Resin and a compatible hardener such as the West System C205 Hardener or West System C209SA Extra Slow Hardener. Remind customers to follow the full surface prep and application sequence for best results — the additive enhances the system but does not replace proper prep work.
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.