High-Density Filler-15.2 oz.
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WEST SYSTEM 404 High-Density Filler is a thickening additive used with epoxy to create a high-strength, non-slumping adhesive for hardware bonding, gap filling, and structural fillets.
Key Features
- Thickening additive for epoxy to boost structural strength
- Formulated for hardware bonding where high cyclic loads are anticipated
- Designed for filleting and gap filling when maximum strength is needed
- Cures to an off-white color
Intended Use
- Marine and boat repair epoxy thickening (structural bonding applications)
- Hardware bonding tasks requiring high-strength, non-slumping mixes
- Fillets and structural gap filling with thickened epoxy
Product Details
- Brand/Line: WEST SYSTEM
- Product: High-Density Filler (404 High-Density Filler)
- Package/Net Weight: 15.2 oz
- SKU (as listed): 655-40415
- Color/Cure: Cures to an off-white color
- Use with: epoxy thickening (high-density adhesive filler category)
Parts Desk Insights
Best Use Case: Use when you need epoxy thickened into a high-density, non-slumping adhesive—ideal for structural fillets and strong gap-filling during repairs or hardware bonding.
Common Issues: Common mistakes include using too much filler and making the mix difficult to apply, or not achieving the intended consistency for filleting/filling; verify the mix consistency before application and follow the epoxy system’s mixing directions for the resin/hardener you’re using.
Related Products & Accessories
- WEST SYSTEM Fillers & Additives (Category) - Browse the fillers & additives category to find complementary fairing (low-density) fillers, sanding/surface-prep options, and related epoxy components.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 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.