---
product_id: 182434578
title: "Duct Seal 321 Duct Sealant #DS-321-4F"
brand: "hardcast"
price: "$218.41"
currency: USD
in_stock: true
category: "Hardcast"
url: https://www.desertcart.us/products/182434578-duct-seal-321-duct-sealant-ds-321-4f
store_origin: US
region: United States of America
---

# Water-based & water resistant Compatible with metal, glass & flex duct 10.8 lbs robust weight Duct Seal 321 Duct Sealant #DS-321-4F

**Brand:** hardcast
**Price:** $218.41
**Availability:** ✅ In Stock

## Summary

> 💨 Seal smart, seal strong — keep your airflow flawless!

## Quick Answers

- **What is this?** Duct Seal 321 Duct Sealant #DS-321-4F by hardcast
- **How much does it cost?** $218.41 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/182434578-duct-seal-321-duct-sealant-ds-321-4f)

## Best For

- hardcast enthusiasts

## Why This Product

- Trusted hardcast brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **One-Gallon Bulk Supply:** Generous 1-gallon pail designed for professional HVAC projects and large-scale use
- • **Eco-Friendly Water Base:** Water-based composition ensures safer handling and easy cleanup
- • **Heavy-Duty Sealant Power:** 10.8 lbs of durable acrylic formula for long-lasting duct sealing
- • **Trusted Industrial Standard:** Ranked #578 in duct tape category with 4.7-star user approval
- • **Versatile Surface Compatibility:** Seals metal, glass fiber, flexible tubing, and duct fabric effortlessly

## Overview

DUCT-SEAL 321 by Hardcast is a 1-gallon, water-based acrylic sealant weighing 10.8 lbs, engineered for industrial HVAC applications. It offers water resistance and superior adhesion to metal, glass fiber, and flexible duct materials, making it a top-rated choice for professionals seeking reliable, eco-conscious duct sealing solutions.

## Description

The item is DUCT-SEAL 321 WATER BASED DUCT - HARDCAST 304156, SEALANT 1-GAL PAIL with UPC: 63853280050. DUCT-SEAL 321 WATER BASED DUCT is manufactured by: HARDCAST. DUCT-SEAL 321 WATER BASED DUCT is a component that has the part number of: 304156. And weighs at around 10.75 lbs.

## Features

- weight: 10.75

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B071ZQXDQZ |
| Best Sellers Rank | #90,069 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #578 in Duct Tape |
| Brand | Hardcast |
| Brand Name | Hardcast |
| Compatible Material | Glass,industrial,metal |
| Customer Reviews | 4.7 out of 5 stars 16 Reviews |
| Item Form | Liquid |
| Item Weight | 10.8 Pounds |
| Material | Acrylic |
| Material Type | Acrylic |
| Number of Items | 1 |
| Part Number | DS-321-4 |
| Style | Industrial |
| Style Name | Industrial |
| Surface Recommendation | Metal, Glass Fiber, Flex Duct, Duct Fabric, Flexible Tubing |
| UPC | 638532800500 |
| Unit Count | 1.00 Count |
| Water Resistance Level | Water Resistant |

## Product Details

- **Brand:** Hardcast
- **Item Weight:** 10.8 Pounds
- **Material:** Acrylic
- **Style:** Industrial
- **Water Resistance Level:** Water Resistant

## Images

![Duct Seal 321 Duct Sealant #DS-321-4F - Image 1](https://m.media-amazon.com/images/I/41VktDq0XjL.jpg)

## Frequently Bought Together

- Hardcast Duct Seal 321 Duct Sealant #DS-321-4F
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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-07-14*