---
product_id: 303805407
title: "Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray"
brand: "red devil"
price: "¥22089"
currency: JPY
in_stock: true
reviews_count: 5
category: "Red Devil"
url: https://www.desertcart.jp/products/303805407-red-devil-0841dx-f-seal-181-fiber-reinforced-water-based
store_origin: JP
region: Japan
---

# Low VOC & LEED EQ 4.1 Compliant Water-based & water resistant UL 181 a-m & b-m certified Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray

**Brand:** red devil
**Price:** ¥22089
**Availability:** ✅ In Stock

## Summary

> 💨 Seal smart, breathe easy — the pro’s choice for HVAC perfection!

## Quick Answers

- **What is this?** Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray by red devil
- **How much does it cost?** ¥22089 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/303805407-red-devil-0841dx-f-seal-181-fiber-reinforced-water-based)

## Best For

- red devil enthusiasts

## Why This Product

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

## Key Features

- • **Made in the USA:** Proudly crafted with precision in Oklahoma for trusted quality
- • **Durable & Flexible:** Fiber reinforced for long-lasting adhesion and crack resistance
- • **Certified Performance:** Meets UL 181 a-m & b-m standards for airtight HVAC sealing
- • **Eco-Conscious Formula:** Low VOC, LEED EQ 4.1 compliant for healthier indoor air quality
- • **Versatile Application:** Works seamlessly on metal, fiberglass, and flex duct systems

## Overview

Red Devil 0841DX F-Seal 181 is a premium fiber reinforced, water-based duct sealant designed for both indoor and outdoor HVAC applications. Certified to UL 181 a-m & b-m standards, it ensures airtight sealing on metal, fiberglass, and flexible ducts. With low VOC content and LEED EQ 4.1 compliance, it supports healthier environments while delivering durable, flexible adhesion. Proudly made in the USA, this 1-gallon gray sealant is the trusted solution for professional-grade HVAC sealing.

## Description

Red Devil F-Seal 181 is a specially formulated fiber reinforced water based duct sealant/mastic for indoor/outdoor use. Suitable for pressure sealing all types of HVAC duct systems including metal, fiberglass ductboard and flexduct. Made in USA. FEATURES: LEED EQ 4.1 Compliant Indoor/Outdoor Excellent Adhesion Excellent Flexibility Low VOC USE ON: Metal and Flexible Ducts Vents Air Conditioners HVAC Appliances SPECIFICATIONS: UL 181 A-M & B-M certified and can be used on all types of HVAC ductwork. ABOUT RED DEVIL: Red Devil is still a privately-owned family business with state-of-the-art manufacturing facilities in Pryor, Oklahoma. Click on the Red Devil link at the top of this page to visit our Brand Store.

Review: Works great
Review: Good for all around applications

## Features

- High quality, fiber reinforced
- UL 181 a-m & b-m certified
- Can be used on all types of HVAC ductwork
- Interior/exterior
- Made in the USA

## Technical Specifications

| Specification | Value |
|---------------|-------|
| ASIN | B01I7JVUO0 |
| Best Sellers Rank | #181,085 in Tools & Home Improvement ( See Top 100 in Tools & Home Improvement ) #291 in Heating & Cooling Ducting Products |
| Brand | Red Devil |
| Brand Name | Red Devil |
| Color | Gray |
| Compatible Material | Plastic |
| Customer Reviews | 4.4 out of 5 stars 1,220 Reviews |
| Global Trade Identification Number | 00075339003466 |
| Included Components | Duct Sealant |
| Item Dimensions | 17.8 x 17.8 x 20.3 centimeters |
| Item Form | Paste |
| Item Type Name | Water Based Duct Sealant, 1 Gallon |
| Item Weight | 1 Pounds |
| Item dimensions L x W x H | 17.8 x 17.8 x 20.3 centimeters |
| Item height | 8 inches |
| Item weight | 1 Pounds |
| Manufacturer | Red Devil |
| Material | Silicone |
| Material Type | Silicone |
| Style | 1 - Pack |
| Style Name | 1 - Pack |
| Supported Standards | UL 181 a-m, UL 181 b-m |
| Surface Recommendation | Duct |
| UPC | 075339003466 |
| Unit Count | 128 Milliliters |
| Water Resistance Level | Water Resistant |
| Water resistance level | Water Resistant |

## Product Details

- **Material:** Silicone
- **Brand:** Red Devil
- **Style:** 1 - Pack
- **Item weight:** 1 Pounds
- **Item dimensions L x W x H:** 17.8 x 17.8 x 20.3 centimeters

## Images

![Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray - Image 1](https://m.media-amazon.com/images/I/61DR9w5x7fL.jpg)
![Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray - Image 2](https://m.media-amazon.com/images/I/61g4OiMBuXL.jpg)
![Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray - Image 3](https://m.media-amazon.com/images/I/61wXviPRg2L.jpg)
![Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray - Image 4](https://m.media-amazon.com/images/I/718Qkc+7HiL.jpg)
![Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray - Image 5](https://m.media-amazon.com/images/I/71BJyuDkMZL.jpg)

## Questions & Answers

**Q: Is the "F" in the bucket like a liquid (brushable) or more like a paste?**
A: It's not quite like a paste but it's not liquidity either and doesn't drip so you can put it on thick.  I love this stuff, not much of a odor as well. I used a cheap chip brush to spread it.

**Q: I'm redoing all the flex ductwork (insulated kind) in a crawl space. should i use the d our f sealant ?**
A: You could use either one.  Both are perfect for what you are doing, but I would use the F-Seal because it has fibers in it.

**Q: Is this safe to use and will it work on gas dryer duct work joints (inside the fittings and outside)?**
A: Sorry, this should not be used on a dryer. It is for HVAC only. Thanks.

**Q: How long do I need to wait before turning on the A/C after application?**
A: Hi, you should wait 24 hours. Thanks....

## Customer Reviews

### ⭐⭐⭐⭐ Works great
*by H***. on 26 July 2020*



### ⭐⭐⭐⭐ Good for all around applications
*by S***G on 2 October 2020*



### ⭐⭐⭐⭐⭐ great buy
*by J***T on 11 March 2025*



## Frequently Bought Together

- Red Devil 0841DX F-Seal 181 Fiber Reinforced Water Based Duct Sealant, 1 Gallon, Gray, Made in USA
- Pro Grade - Chip Paint Brushes - 12 Ea 2 Inch Chip Paint Brush Light Brown

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*Product available on Desertcart Japan*
*Store origin: JP*
*Last updated: 2026-02-04*