---
product_id: 273973810
title: "Fiberglass Supply Depot 4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (Quart Kit)"
brand: "fiberglass supply depot"
price: "102473CFA"
currency: XOF
in_stock: true
reviews_count: 13
url: https://www.desertcart.sn/products/273973810-fiberglass-supply-depot-4-lb-density-expanding-pour-foam-2
store_origin: SN
region: Senegal
---

# Closed-cell foam for soundproofing 5 min full cure time 4 lb density for superior buoyancy Fiberglass Supply Depot 4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (Quart Kit)

**Brand:** fiberglass supply depot
**Price:** 102473CFA
**Availability:** ✅ In Stock

## Summary

> 🛠️ Elevate your projects with foam that floats, seals, and silences like a pro!

## Quick Answers

- **What is this?** Fiberglass Supply Depot 4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (Quart Kit) by fiberglass supply depot
- **How much does it cost?** 102473CFA with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sn](https://www.desertcart.sn/products/273973810-fiberglass-supply-depot-4-lb-density-expanding-pour-foam-2)

## Best For

- fiberglass supply depot enthusiasts

## Why This Product

- Trusted fiberglass supply depot brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Speedy Setup:** Fully cures in just 5 minutes, so your projects move fast without waiting around.
- • **Seal & Silence:** Closed-cell polyurethane structure provides excellent waterproofing and soundproofing.
- • **Float Above the Rest:** 4 lb density foam delivers unmatched buoyancy for boats, docks, and floating decoys.
- • **Precision Performance:** Ideal working temperature range (75°-80°F) ensures consistent expansion and flawless results.
- • **Versatile Crafting Power:** Perfect for sculpting, carving, filling voids, and laminating with polyester or epoxy resins.

## Overview

Fiberglass Supply Depot’s 4 lb density expanding pour foam is a two-part polyurethane closed-cell liquid foam designed for superior flotation, soundproofing, insulation, and filling applications. It cures fully in 5 minutes, is waterproof, and compatible with polyester, epoxy, and vinyl ester resins, making it a versatile choice for boat docks, floating decoys, taxidermy, and industrial sound dampening.

## Features

- Flotation Foam is a polyurethane 2-part foam that, when mixed in equal parts and poured in place this foam will soundproof, insulate, or provide extra buoyancy.
- 4LB. Density polyurethane flotation Foam Quart Kit; Consists of 1 pint of Part A and 1 pint of Part B and produces 1/2 cubic foot.
- Once fully cured this foam can be laminated over with any type of polyester, epoxy or vinyl ester resin without melting.
- The 4LB density also works well in floating decoy or taxidermy applications as well as many other sculpting, casting, carving and other filling applications
- All expansion rates and times given are temperature critical. Temperatures below 75° F will lower the expansion rate therefore requiring more foam. Ideal working temperature is 75° to 80° F or above. Accurate measuring of these products is extremely critical. Working time before foaming: approx. 45 seconds Time before full expansion: approx. 5 minutes

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Asin | B08T255GS5 |
| Best Sellers Rank | #31,403 in Industrial & Scientific (See Top 100 in Industrial & Scientific) #63 in Urethane Adhesives |
| Brand Name | Fiberglass Supply Depot |
| Color | Black, Clear, Yellow |
| Compatible Material | Vinyl |
| Container Type | Bottle |
| Customer Reviews | 4.3 4.3 out of 5 stars (157) 4.3 out of 5 stars |
| Full Cure Time | 5 minutes |
| Item Form | Liquid |
| Item Package Quantity | 1 |
| Manufacturer | Fiberglass Supply Depot Inc. |
| Material Type | Foam,Resin |
| Number Of Pieces | 2 |
| Other Special Features Of The Product | Versatility |
| Part Number | poly4lbqk |
| Specific Uses For Product | Floating Decoy, Taxidermy |
| Unit Count | 64 Ounce |
| Upc | 819794022897 |
| Viscosity Level | Medium to High |
| Volume | 1 quarts |
| Water Resistance Level | Waterproof |

## Product Details

- **Brand:** Fiberglass Supply Depot
- **Item Form:** Liquid
- **Material:** Foam,Resin
- **Special Feature:** Versatility
- **Specific Uses For Product:** Floating Decoy, Taxidermy

## Images

![Fiberglass Supply Depot 4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (Quart Kit) - Image 1](https://m.media-amazon.com/images/I/81XhbU5HAlL.jpg)

## Questions & Answers

**Q: What is the cure time?  I see 5 minute until "full expansion" but nowhere on the package do I find the cure time.**
A: Around 30-60 minutes

**Q: If one doesn't use the whole kit how long will the 2 parts last?**
A: As long as you make them.

**Q: would this provide floatation if used in the bow of a kayak?**
A: Yes, that is one of its intended uses. It is a closed cell foam.

**Q: Question any way to pump this? I have a void under a concrete walkway and I need to get it back 4 feet The void is 4x4 and 2 to 6 inches deep.**
A: You only have a brown 30 seconds after you mix the product to put it in the location that you are wanting depending on temperature if you have a mixing tip then you could pump it however it needs to be agitated for 20 seconds

## Customer Reviews

### ⭐⭐⭐⭐⭐ Great product! Directions a bit off.
*by  on Reviewed in the United States August 3, 2024*

This works great and made a nice, firm filler that I needed for a place on my kayak. It was easily sand-able and paintable. It is firmer/stiffer than the spray foam you buy in cans at the home improvement store. Just be aware that the directions are a bit off. In the video we watched online, it looked as if it foamed up instantly, and the directions said to count a number of seconds and no more before pouring. Our experience was that it took a bit longer for it to foam up, and we wasted some that poured through some holes in the cavity we were trying to fill. I would say an extra 10-15 seconds would have worked better.

### ⭐⭐⭐⭐⭐ 2part foam
*by  on Reviewed in the United States March 6, 2026*

The foam is exactly what I needed. It worked perfectly. Awesome product.

### ⭐⭐⭐⭐⭐ Expands quickly
*by  on Reviewed in the United States January 4, 2024*

I created a rear wing which was hollow and needed to strong as it is active and used as an air brake so I needed to fill it with foam. The 4 pound foam was perfect but calculating the internal volume was difficult. To be sure I wasn't going to come up short I added a little extra and did two pours. Because of the shape I couldn't see where the first ended so I proceeded to do the second pour. As soon as I saw it I had like 2 seconds before it over flowed. All good as I planned for this and could just cut the excess off. So be warned and prepared if you mixed too much. It sticks to everything and there is no stopping it. My wing now is as hard as a rock and strong so it worked well for me.

## Frequently Bought Together

- 4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (Quart Kit)
- Fiberglass Supply Depot 6LB Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boats, Dock Flotation, Carving, Soundproofing, Filling Voids, and Insulation (Quart Kit)
- 2 Lb Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (Quart Kit)

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*Product available on Desertcart Senegal*
*Store origin: SN*
*Last updated: 2026-08-16*