Fiberglass Supply Depot 6LB Expanding Pour Foam Quart Kit - Buoyant

In this review of the Fiberglass Supply Depot 6LB Density Expanding Pour Foam Quart Kit the bottom line is clear: this is a practical, small-volume two-part polyurethane foam for anyone needing reliable buoyancy, insulation or carving stock. The kit mixes 1 pint of Part A with 1 pint of Part B to produce about 0.375 cubic feet of closed-cell foam that can be laminated over with polyester, epoxy or vinyl ester resins once cured. It is especially useful where controlled, in-place pouring and a moderate 6LB density are required.

Key Features

• Two-part formulation: Equal parts of Part A and Part B are mixed and poured to create a consistent closed-cell foam that provides buoyancy and insulation.
• 6LB density: The mid-weight foam balances rigidity and carvability, making it suitable for flotation, decoys and sculpting projects.
• Quart kit yield: The 1 pint + 1 pint kit produces approximately 0.375 cubic feet of cured foam, convenient for small repairs and fills.
• Resin compatible: Once fully cured the foam accepts polyester, epoxy or vinyl ester laminates without melting, allowing reinforcement or fairing.
• Fast working profile: Working time before foaming is about 45 seconds with full expansion around 5 minutes at recommended temperatures, enabling quick turnarounds.
• Temperature sensitive: Best performance between 75 and 80 F; lower temperatures reduce expansion and may require more material.

Who It's For

The kit is aimed at boaters, dock builders, hobbyists and modelers who need reliable buoyancy or a carvable closed-cell foam for decoys, taxidermy, filling voids and soundproofing. Its small yield and compatibility with common marine resins make it practical for patching cavities or creating lightweight floatation blocks where larger drums would be wasteful.

It is less suitable for very large displacement flotation jobs that require bulk quantities or for users who cannot reliably control ambient temperature during mixing, since expansion rates and final yield are temperature dependent. Professionals needing industrial-scale output should look for larger volume packaging.

Pros & Cons

Pros

• Provides genuine closed-cell buoyancy and insulation in a compact quart kit.
• Cures to a surface that can be laminated with polyester, epoxy or vinyl ester resins for reinforcement.
• Work time and fast expansion allow quick pours and short project cycles.
• 6LB density offers a good balance for carving, sculpting and float applications.

Cons

• Temperature-sensitive expansion means yields vary below 75 F and colder conditions may require additional material.
• Small 0.375 cu ft yield limits use to small repairs and projects, not large-scale flotation jobs.

Specifications

Product Type	Two-part polyurethane expanding pour foam
Density	6LB
Kit Size	1 pint Part A + 1 pint Part B (quart kit)
Yield	Approximately 0.375 cubic feet
Working Time	About 45 seconds before foaming
Full Expansion Time	Approximately 5 minutes (temperature dependent)
Post-cure Compatibility	Laminatable with polyester, epoxy or vinyl ester resins

Our Verdict

The Fiberglass Supply Depot 6LB Quart Kit is a solid choice for small boat repairs, dock flotation patches, carving and hobby applications where a mid-density closed-cell foam is needed. It is good value for projects that fit the 0.375 cu ft yield and where working temperature can be controlled, offering easy post-cure lamination and a practical balance of buoyancy and carveability.

Frequently Asked Questions

Can this foam be laminated over with standard marine resins?
Yes. Once fully cured the foam accepts polyester, epoxy and vinyl ester resins without melting, making it suitable for reinforced repairs.

How much foam does the quart kit produce?
The kit (1 pint Part A + 1 pint Part B) produces about 0.375 cubic feet of cured foam under recommended temperature conditions.

What temperature is best for mixing and pouring?
Ideal working temperature is 75 to 80 F or above; temperatures below 75 F reduce expansion and can change yield.