---
product_id: 423761958
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: "1705 Lei"
currency: RON
in_stock: true
reviews_count: 5
category: "Fiberglass Supply Depot"
url: https://www.desertcart.ro/products/423761958-fiberglass-supply-depot-4-lb-density-expanding-pour-foam-2
store_origin: RO
region: Romania
---

# 2 cubic feet coverage per kit 5 min full expansion time 4 lb/ft³ density for robust 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:** 1705 Lei
**Availability:** ✅ In Stock

## Summary

> 🚤 Float, fill, and fortify with foam that means business!

## 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?** 1705 Lei with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.ro](https://www.desertcart.ro/products/423761958-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

- • **Precision Application:** Temperature-sensitive expansion and 45-second working time demand expert handling—perfect for pros who value accuracy and quality.
- • **Resin-Compatible Finish:** Can be laminated with polyester, epoxy, or vinyl ester resins without melting, ensuring seamless integration into advanced projects.
- • **Rapid Expansion & Curing:** Expands fully in just 5 minutes, enabling quick project turnaround without downtime.
- • **Superior Structural Support:** 4 lb density foam designed to withstand moderate loads, perfect for boat decks and gas tank flotation.
- • **Versatile Multi-Use Formula:** Ideal for flotation, soundproofing, insulation, sculpting, casting, and filling voids—one kit, endless possibilities.

## Overview

Fiberglass Supply Depot’s 4 lb density expanding pour foam is a high-performance 2-part polyurethane kit delivering 2 cubic feet of closed-cell foam. Engineered for flotation, soundproofing, insulation, and sculpting, it cures rapidly and supports moderate loads, making it the go-to choice for professionals seeking durable, versatile, and resin-compatible foam solutions.

## 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: Great product!!!!
Review: Good product.

## Features

- Causes skin irritation.
- Harmful if inhaled.
- May cause allergy or asthma symptoms or breathing difficulties if inhaled.
- May cause an allergic skin reaction.
- May cause damage to organs through prolonged or repeated exposure (respiratory tract).
- May cause respiratory irritation.
- 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 |
| Best Sellers Rank | 1,099,070 in DIY & Tools ( See Top 100 in DIY & Tools ) 40,857 in Adhesives & Sealers |
| Brand | Fiberglass Supply Depot |
| Coverage | 2 cubic feet (volume coverage) |
| Customer Reviews | 4.3 out of 5 stars 234 Reviews |
| Manufacturer | Fiberglass Supply Depot Inc. |
| Material | Polyurethane Foam |
| Recommended Uses For Product | Flotation, Soundproofing, Insulation, Filling Voids, Sculpting, Casting |
| Recommended uses for product | Flotation, Soundproofing, Insulation, Filling Voids, Sculpting, Casting |
| UPC | 819794022934 |

## Product Details

- **Brand:** Fiberglass Supply Depot
- **Manufacturer:** Fiberglass Supply Depot Inc.
- **Material:** Polyurethane Foam
- **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/81ySuM57MmL.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

### ⭐⭐⭐⭐⭐ Great product!!!!
*by L***E on 18 October 2025*



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



### ⭐⭐⭐⭐⭐ great product
*by A***H on 28 July 2025*



## 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)

---

## Why Shop on Desertcart?

- 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016
- 🌍 **Shop Globally** — Access 737+ million products across 21 categories
- 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price
- 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members)
- 🔒 **Secure Payments** — Trusted payment options with buyer protection
- ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews

**Shop now:** [https://www.desertcart.ro/products/423761958-fiberglass-supply-depot-4-lb-density-expanding-pour-foam-2](https://www.desertcart.ro/products/423761958-fiberglass-supply-depot-4-lb-density-expanding-pour-foam-2)

---

*Product available on Desertcart Romania*
*Store origin: RO*
*Last updated: 2026-01-31*