---
product_id: 680856745
title: "Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill"
brand: "fiberglass supply depot"
price: "1075.59 DT"
currency: TND
in_stock: true
reviews_count: 5
category: "Fiberglass Supply Depot"
url: https://www.desertcart.tn/products/680856745-fiberglass-supply-depot-4-pounds-density-expansion-foam-2-part
store_origin: TN
region: Tunisia
---

# Closed-cell foam for superior soundproofing 45 sec working time, 5 min full expansion 4 lbs density for robust flotation Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill

**Brand:** fiberglass supply depot
**Price:** 1075.59 DT
**Availability:** ✅ In Stock

## Summary

> 🛠️ Float, fill, and fortify—foam that means business!

## Quick Answers

- **What is this?** Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill by fiberglass supply depot
- **How much does it cost?** 1075.59 DT with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.tn](https://www.desertcart.tn/products/680856745-fiberglass-supply-depot-4-pounds-density-expansion-foam-2-part)

## 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

- • **Multi-Use Mastery:** Ideal for soundproofing, insulation, sculpting, casting, and filling voids with precision.
- • **Premium 4LB Density:** Engineered for durable flotation and moderate load support—perfect for boats and docks.
- • **Rapid Expansion Formula:** Mix and apply with a quick 45-second working window and full cure in just 5 minutes.
- • **Versatile Compatibility:** Seamlessly laminates with polyester, epoxy, or vinyl ester resins without melting.
- • **Temperature-Optimized Performance:** Best results at 75°-80°F, ensuring consistent expansion and reliable application.

## Overview

Fiberglass Supply Depot’s 4LB Density Expansion Foam is a high-performance 2-part closed-cell polyurethane solution delivering 2 cubic feet of durable, soundproof, and insulating foam. Designed for boat flotation, dock support, and versatile applications like sculpting and casting, it cures rapidly and bonds flawlessly with common resins, making it the go-to choice for professionals demanding strength and precision.

## Description

This 4LB density foam is suitable for most float applications that require more support than that of 2LB offers. This foam is recommended for use on gas tank support and some deck areas. Choose this density if you think the foam will need to withstand small to moderate loads. The density of 4LB also works well in floating bait or taxidermy applications, as well as many other sculpting, casting, notching 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 2-part polyurethane foam that, when mixed in equal parts and put in place, this foam will be soundproof, insulate or provide extra buoyancy.
- 4 lbs. 1 Gallon Density Polyurethane Flotation Foam Kit; Consists of 1/2 Gallon Part A and 1/2 Gallon Part B and produces 2 cubic feet.
- Once fully cured, this foam can be laminated with any type of polyester, epoxy or vinyl ester resin without melting.
- 4LB density also works well in floating bait or taxidermy applications, as well as many other sculpting, casting, carving and other filling applications.
- All provided expansion rates and times are temperature critical. Temperatures below 75° F will decrease the expansion rate, therefore requiring more foam. Ideal working temperature is 75° to 80° F or higher. Accurate measurement 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 |
| Manufacturer | Fiberglass Supply Depot Inc. |
| Manufacturer reference | FBAPOLY4LBGK |
| 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, Sculpting, Casting
- **UPC:** 819794022934

## Images

![Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill - Image 1](https://m.media-amazon.com/images/I/41S-u-+aQ2L.jpg)
![Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill - Image 2](https://m.media-amazon.com/images/I/41cVcze5RmL.jpg)
![Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill - Image 3](https://m.media-amazon.com/images/I/41z05kTc6bL.jpg)
![Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill - Image 4](https://m.media-amazon.com/images/I/51-GJ8ojZYL.jpg)
![Fiberglass Supply Depot 4 Pounds. Density Expansion Foam, 2-Part PU Closed Cell Liquid Foam for Boat Flotation and Dock, Acoustic Insulation, Vaz Fill - 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)
- 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 Tunisia*
*Store origin: TN*
*Last updated: 2026-02-01*