---
product_id: 282511399
title: "4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (2 Quart Kit)"
brand: "fiberglass supply depot"
price: "472 zł"
currency: PLN
in_stock: true
reviews_count: 4
category: "Fiberglass Supply Depot"
url: https://www.desertcart.pl/products/282511399-4-lb-density-expanding-pour-foam-2-part-polyurethane-closed
store_origin: PL
region: Poland
---

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

**Brand:** fiberglass supply depot
**Price:** 472 zł
**Availability:** ✅ In Stock

## Summary

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

## Quick Answers

- **What is this?** 4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (2 Quart Kit) by fiberglass supply depot
- **How much does it cost?** 472 zł with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.pl](https://www.desertcart.pl/products/282511399-4-lb-density-expanding-pour-foam-2-part-polyurethane-closed)

## 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 5-Minute Cure:** Get your projects moving fast with quick setting and minimal downtime.
- • **Resin-Compatible Finish:** Laminates seamlessly with polyester, epoxy, or vinyl ester without melting or damage.
- • **Versatile Application Power:** Perfect for flotation, soundproofing, insulation, and filling voids—one kit, endless solutions.
- • **Precision-Mixed 2-Part Formula:** Ensures consistent, uniform expansion every time for flawless results.
- • **Temperature-Optimized Performance:** Ideal working range of 75°-80°F guarantees maximum expansion and efficiency.

## Overview

Fiberglass Supply Depot’s 4 lb density expanding pour foam is a high-performance, 2-part polyurethane closed-cell liquid foam designed for boat and dock flotation, soundproofing, insulation, and filling voids. This 2-quart kit mixes easily, cures fully in 5 minutes, and offers water resistance and compatibility with various resins, making it a versatile and reliable choice for professional-grade projects.

## Description

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 (2 Quart Kit): desertcart.com: Industrial & Scientific

Review: Works well - Easy to use and set up well. Product worked predictably and set up uniformly. Another brand I have used in the past started not performing as desired as it had a violent reaction and non uniform results making it unusable. Cost for these smaller bottles was excessive, but at least it worked!
Review: Prompt shipping, easy pour, easy mix. - Sets up just about the same as other brands, so the advantage is the packaging. The bottles have a 2-part seal, so less risk of moisture contaminating the components and spoiling the bottom half of the container. Good move! Tip - refrigerate part B to get longer pot life.

## 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 1/2 Gallon Kit; Consists of 1 quart of Part A and 1 quart of Part B and produces 1 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 | B08T21WRF9 |
| Best Sellers Rank | #392,970 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #356 in Urethane Adhesives |
| Brand | Fiberglass Supply Depot |
| Color | Clear |
| Date First Available | January 14, 2021 |
| Full Cure Time | 5 Minutes |
| Item Form | Liquid |
| Item Package Quantity | 1 |
| Item Volume | 2 Quarts |
| Item Weight | 5.57 pounds |
| Manufacturer | Fiberglass Supply Depot Inc. |
| Material | Foam,Resin |
| Package Dimensions | 9.21 x 7.36 x 4.8 inches |
| Package Information | Can |
| Special Feature | soundproofing, insulation, buoyancy, laminating with certain resins without melting |
| Specific Uses For Product | Flooring, Boat, Dock, Insulation, Soundproofing |
| UPC | 819794022910 |
| Unit Count | 1 Count |
| Viscosity | High |
| Viscosity Level | High |
| Water Resistance Level | Water Resistant |

## Product Details

- **Brand:** Fiberglass Supply Depot
- **Item Form:** Liquid
- **Material:** Foam,Resin
- **Special Feature:** soundproofing, insulation, buoyancy, laminating with certain resins without melting
- **Specific Uses For Product:** Flooring, Boat, Dock, Insulation, Soundproofing

## Images

![4 Lb. Density Expanding Pour Foam, 2 Part Polyurethane Closed Cell Liquid Foam for Boat and Dock Flotation, Soundproofing, Filling Voids, and Insulation (2 Quart Kit) - Image 1](https://m.media-amazon.com/images/I/814gSi7cACL.jpg)

## Questions & Answers

**Q: i'm new at this.what does density mean i see 2lb 4lb 6lb? thanks**
A: The higher the number, the higher the density equaling stronger flotation.

**Q: How well does this hold up to exposure to water? Applied to the bottom of a boat rear swim platform, for example, to reduce noise?**
A: Not good exposed to the elements.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works well
*by J***T on March 18, 2023*

Easy to use and set up well. Product worked predictably and set up uniformly. Another brand I have used in the past started not performing as desired as it had a violent reaction and non uniform results making it unusable. Cost for these smaller bottles was excessive, but at least it worked!

### ⭐⭐⭐⭐⭐ Prompt shipping, easy pour, easy mix.
*by P***K on February 7, 2023*

Sets up just about the same as other brands, so the advantage is the packaging. The bottles have a 2-part seal, so less risk of moisture contaminating the components and spoiling the bottom half of the container. Good move! Tip - refrigerate part B to get longer pot life.

### ⭐⭐⭐⭐ Great for repairing old fence
*by R***H on May 22, 2023*

got this to repair a fence post that was searing badly and nearly failed. I dug around it a bit then filled this material in the hole. It did a great repair. Highly recommend it

## 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 (2 Quart Kit)
- 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)
- 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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**Shop now:** [https://www.desertcart.pl/products/282511399-4-lb-density-expanding-pour-foam-2-part-polyurethane-closed](https://www.desertcart.pl/products/282511399-4-lb-density-expanding-pour-foam-2-part-polyurethane-closed)

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*Product available on Desertcart Poland*
*Store origin: PL*
*Last updated: 2026-04-27*