---
product_id: 692715743
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: "216692 Ft"
currency: HUF
in_stock: false
reviews_count: 5
category: "Fiberglass Supply Depot"
url: https://www.desertcart.hu/products/692715743-fiberglass-supply-depot-4-lb-density-expanding-pour-foam-2
store_origin: HU
region: Hungary
---

# 2-part polyurethane formula for durable, closed-cell foam Rapid 5-minute full expansion time 4 lb density for superior flotation support 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:** 216692 Ft
**Availability:** ❌ Out of Stock

## Summary

> 🛠️ Expand your possibilities with 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?** 216692 Ft with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.hu](https://www.desertcart.hu/products/692715743-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:** Expands fully in just 5 minutes, letting you move fast and stay ahead on your projects.
- • **Creative Freedom:** Perfect for sculpting, carving, casting, and even floating decoys—unlock your DIY potential with professional-grade foam.
- • **Versatile & Tough:** Closed-cell polyurethane foam that laminates seamlessly with polyester, epoxy, or vinyl ester resins without melting.
- • **Float with Confidence:** 4 lb density foam engineered to support moderate loads—perfect for boats, docks, and gas tank stabilization.
- • **Precision Performance:** Ideal working temperature range of 75°-80°F ensures consistent expansion and reliable results every time.

## Overview

Fiberglass Supply Depot’s 4 lb density expanding pour foam is a high-performance, 2-part polyurethane closed-cell liquid foam designed for flotation, soundproofing, insulation, and filling voids. This 1-gallon kit produces 2 cubic feet of durable foam that cures quickly and bonds with various resins, making it ideal for marine, construction, and creative applications where strength and reliability are non-negotiable.

## Description

This 4LB density foam is suited well for most flotation applications that require more support than the 2LB offers. This foam is recommended to be used when supporting gas tanks and some deck areas. Choose this density if you feel that the foam will be required to withstand minor to moderate loads. The 4LB density also works well in floating decoy or taxidermy applications as well as many other sculpting, casting, carving and other filling applications

Review: Awesome stuff, I used it to fill holes used from animals going under my cement driveway and walkway. Fantastic results and hardens like a rock
Review: Works well. Be quick and ready for it, it expands quickly and will come for you if you're not prepared to control it.

## 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 |
| Country of Origin | USA |
| Item Dimensions LxWxH | 25.4 x 22.9 x 15.2 Centimeters |
| Item Weight | 4 kg 820 g |
| Item part number | FBAPOLY4LBGK |
| Manufacturer | Fiberglass Supply Depot Inc. |
| Net Quantity | 192 Fluid Ounces |
| Product Dimensions | 25.4 x 22.86 x 15.24 cm; 4.82 kg |

## Product Details

- **Brand:** Fiberglass Supply Depot
- **Manufacturer:** Fiberglass Supply Depot Inc.
- **Material:** Foam,Resin
- **Recommended Uses For Product:** Flotation, Soundproofing, Insulation, Filling Voids
- **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/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 2](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 3](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 4](https://m.media-amazon.com/images/I/51-GJ8ojZYL.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/519cSzhqfkL.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

### ⭐⭐⭐⭐⭐ Review
*by L***E on 18 October 2025*

Awesome stuff, I used it to fill holes used from animals going under my cement driveway and walkway. Fantastic results and hardens like a rock

### ⭐⭐⭐⭐⭐ Review
*by R***H on 8 March 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.

### ⭐⭐⭐⭐⭐ Review
*by A***H on 28 July 2025*

It worked perfectly to replace floatation foam in a boat

## 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)
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- 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 Hungary*
*Store origin: HU*
*Last updated: 2026-02-11*