--- product_id: 680856745 title: "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: "1394 Lei" currency: RON in_stock: true category: "Fiberglass Supply Depot" url: https://www.desertcart.ro/products/680856745-4-pounds-density-expansion-foam-2-part-pu-closed-cell store_origin: RO region: Romania --- # Closed-cell foam for soundproofing 5 min full expansion time 4 lbs density for robust flotation 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:** 1394 Lei **Availability:** ✅ In Stock ## Summary > 🛠️ Float, fill, and fortify—foam that works as hard as you do! ## Quick Answers - **What is this?** 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?** 1394 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/680856745-4-pounds-density-expansion-foam-2-part-pu-closed-cell) ## 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-Purpose Use Cases:** Perfect for soundproofing, insulation, sculpting, casting, and even taxidermy—unlock creative and practical potential. - • **Versatile Compatibility:** Seamlessly laminates with polyester, epoxy, or vinyl ester resins without melting, ensuring durable finishes. - • **Superior Buoyancy & Support:** 4LB density foam designed to handle moderate loads, perfect for boat flotation and gas tank support. - • **Temperature-Optimized Performance:** Best results at 75°-80°F; precise mixing critical to maximize expansion and strength. - • **Rapid Expansion & Easy Application:** Expands fully in just 5 minutes with a quick 45-second working time—ideal for efficient project completion. ## Overview Fiberglass Supply Depot’s 4LB Density Expansion Foam is a high-performance 2-part polyurethane closed-cell foam delivering 2 cubic feet of durable, buoyant, and soundproof material. Engineered for boat flotation, insulation, and versatile crafting applications, it cures quickly and bonds with common resins without damage. Ideal for professionals demanding reliable strength and multi-functionality in one kit. ## 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. ## 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 | | Brand Name | Fiberglass Supply Depot | | Coverage | 2 cubic feet | | Customer Reviews | 4.4 4.4 out of 5 stars (247) | | Manufacturer | Fiberglass Supply Depot Inc. | | Manufacturer Part Number | FBAPOLY4LBGK | | Material Type | Foam, Resin | | Recommended Uses For Product | Flotation, Soundproofing, Insulation, Filling Voids, Sculpting, Casting | | UPC | 819794022934 | | Unit Count | 192 Milliliters | ## Product Details - **Brand:** Fiberglass Supply Depot - **Manufacturer:** Fiberglass Supply Depot Inc. - **Material:** Foam, Resin - **Number of Items:** 1 - **Recommended uses for product:** Flotation, Soundproofing, Insulation, Filling Voids, Sculpting, Casting ## Images ![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/611pMIJrAfL.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. ## 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/680856745-4-pounds-density-expansion-foam-2-part-pu-closed-cell](https://www.desertcart.ro/products/680856745-4-pounds-density-expansion-foam-2-part-pu-closed-cell) --- *Product available on Desertcart Romania* *Store origin: RO* *Last updated: 2026-07-23*