---
product_id: 273973809
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 (1 Gallon Kit)"
brand: "fiberglass supply depot"
price: "6783631₫"
currency: VND
in_stock: true
reviews_count: 13
category: "Fiberglass Supply Depot"
url: https://www.desertcart.vn/products/273973809-fiberglass-supply-depot-4-lb-density-expanding-pour-foam-2
store_origin: VN
region: Vietnam
---

# Closed-cell foam for soundproofing 5 min full expansion time 4 lb density for superior flotation 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 (1 Gallon Kit)

**Brand:** fiberglass supply depot
**Price:** 6783631₫
**Availability:** ✅ In Stock

## Summary

> 🛠️ Float, fill, and fortify—foam that works as hard as you do!

## 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 (1 Gallon Kit) by fiberglass supply depot
- **How much does it cost?** 6783631₫ with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.vn](https://www.desertcart.vn/products/273973809-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

- • **Rapid Expansion:** Expands fully in just 5 minutes—work fast, seal tight
- • **Resin Compatible:** Laminates seamlessly with polyester, epoxy, or vinyl ester resins
- • **Buoyant Powerhouse:** 4 lb density foam delivers unmatched flotation for boats and docks
- • **Soundproof & Insulate:** Closed-cell structure blocks noise and locks in temperature
- • **Versatile Application:** Perfect for sculpting, casting, filling voids, and more

## Overview

Fiberglass Supply Depot’s 4 lb density expanding pour foam is a 2-part polyurethane closed-cell liquid foam kit that produces 2 cubic feet of high-performance flotation, soundproofing, and insulation material. Designed for quick 5-minute expansion and compatibility with various resins, it’s ideal for boat and dock applications, as well as sculpting and filling tasks, delivering professional-grade results with heat resistance and durability.

## Description

Buy 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 (1 Gallon Kit): Urethane Adhesives - desertcart.com ✓ FREE DELIVERY possible on eligible purchases

Review: Good product. - Works well. Be quick and ready for it, it expands quickly and will come for you if you're not prepared to control it.
Review: Works great - Works great , quick set up and easy to use

## 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 1 Gallon Kit; Consists of 1/2 gallon of Part A and 1/2 gallon of Part B and produces 2 cubic feet.
- 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 | B08T2195F8 |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #56,657 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #81 in Urethane Adhesives |
| Coverage | 2 cubic feet |
| Customer Reviews | 4.5 4.5 out of 5 stars (241) |
| Date First Available | August 19, 2021 |
| Item Package Quantity | 1 |
| Item Weight | 10.61 pounds |
| Manufacturer | Fiberglass Supply Depot Inc. |
| Material | Foam,Resin |
| Part Number | FBAPOLY4LBGK |
| Product Dimensions | 10 x 9 x 6 inches |
| Special Features | Heat Resistant |
| Usage | Boat, Dock |

## Product Details

- **Brand:** Fiberglass Supply Depot
- **Manufacturer:** Fiberglass Supply Depot Inc.
- **Material:** Foam,Resin
- **Recommended Uses For Product:** Flotation, Soundproofing, Insulation, Filling Voids, Sculpting, Casting
- **UPC:** 819794022934

## 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 (1 Gallon Kit) - Image 1](https://m.media-amazon.com/images/I/41LTYo7PPjL.jpg)
![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 (1 Gallon Kit) - Image 2](https://m.media-amazon.com/images/I/41S-u-+aQ2L.jpg)
![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 (1 Gallon Kit) - Image 3](https://m.media-amazon.com/images/I/41cVcze5RmL.jpg)
![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 (1 Gallon Kit) - Image 4](https://m.media-amazon.com/images/I/41z05kTc6bL.jpg)
![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 (1 Gallon Kit) - Image 5](https://m.media-amazon.com/images/I/51-GJ8ojZYL.jpg)

## Questions & Answers

**Q: What is the compressive strength of the foam, in  PCF?**
A: They only give the compressive strength in PSI and that is 78 for the 4lb foam

**Q: What is the viscosity of the liquids before they mix?**
A: The best way to describe it would be like warm pancake syrup.

**Q: i'm new at this..what does density mean i see 2lb..4lb..6lb? thanks**
A: Think of it as hardness or strength. The 2lb will be more sponge like 6 will be harder.

**Q: Can you use pole foam to insulate the walls of a shop? Does it go thru a heat?  Will it blister the tyvek or metal on the outside?**
A: It doesn't fill a very big volume like spray foam. It is very liquid and comes out of any cracks. Will set up hard as a rock though.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Good product.
*by R***H on March 8, 2025*

Works well. Be quick and ready for it, it expands quickly and will come for you if you're not prepared to control it.

### ⭐⭐⭐⭐⭐ Works great
*by J***D on May 28, 2025*

Works great , quick set up and easy to use

### ⭐⭐⭐⭐⭐ Pool step repair.
*by 1***Y on December 20, 2025*

Being a more dense foam I was hoping for more expansion but it did the job. I used this to repair my pool steps from where improper install caused the dirt to wash out underneath them. This filled the void well.

## 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 (1 Gallon Kit)
- Custom Shop Paint Mixing Cups Plastic Measuring Cup Epoxy Resin, Disposable or Reusable, 32-Ounce Quart - Pack of 12 - Graduated, Mixing Ratios, Automotive Painting Acrylic Art Crafts Kitchen
- 6 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boats, Dock Flotation, Carving, Soundproofing, Filling Voids, and Insulation (1 Gallon Kit)

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*Product available on Desertcart Vietnam*
*Store origin: VN*
*Last updated: 2026-01-26*