Overview
Barron Equipment supplies the Action Industries B4711-FL-W-8, an 11-inch large polypropylene flex brush weather seal designed for industrial and commercial door openings with oversized gaps. This is the largest brush profile in the Action Industries Flex Brush lineup, providing dense filament coverage across an 11-inch contact area to block air infiltration, dust, debris, pests, and light on doors where standard 1- to 3-inch brush seals cannot reach.
The 100% synthetic construction eliminates the metal spine found in traditional strip brush. The polypropylene filaments are bonded directly into a flexible backing, producing a seal that is up to 40% lighter than metal-backed alternatives and completely immune to corrosion. This makes it well suited for moisture-prone environments, chemical exposure areas, wash-down facilities, coastal buildings, and cold storage entry points where metal-backed brush degrades over time.
Why Choose Flex Brush Over Traditional Strip Brush
Traditional large strip brush relies on a rigid metal rod with filaments crimped around it. That metal core adds weight, limits flexibility, and introduces corrosion risk in wet or chemically active environments. The Flex Brush replaces the metal rod with a homogeneous bond between a flexible polypropylene backing and the brush filaments. There is no metal anywhere in the finished seal.
This design delivers several practical advantages for installers and facility managers. The seal is lighter and easier to handle on ladders, lifts, and scaffolding during overhead installations. It can be trimmed to length on-site with standard tools. And because the polypropylene filaments do not absorb water, the brush will not freeze in sub-zero conditions or swell in high-humidity environments — maintaining consistent seal contact year-round.
Specifications
The B4711-FL-W-8 is sold as an individual 8-foot section. Key specifications are listed below.
- Part Number: B4711-FL-W-8
- Brush Size: 11 inches
- Section Length: 8 feet
- Filament Material: Polypropylene
- Backing Material: Flexible polymer (metal-free)
- Retainer Compatibility: #7 large channel retainer
- Retainer Family: Large
- Product Family: Large Flex Brush
Compatible Applications
An 11-inch brush profile is designed for industrial door openings with large gaps between the door edge and the frame, header, or jamb. Typical installations include rolling steel doors, sectional overhead doors on warehouses and distribution centers, aircraft hangar doors, large self-storage facilities, agricultural buildings, loading dock perimeters, and freight terminals. The seal is also used in specialty applications where oversized gaps result from structural settling, non-standard door sizing, or equipment clearance requirements.
For doors with smaller gaps, Barron Equipment also carries the standard Flex Brush (fits #4 retainers) and the Slim-Line Flex Brush (fits #2.5 retainers). Contact Barron’s product specialists for help selecting the right brush size and retainer profile for your application.
Other Large Flex Brush Sizes
The B4711-FL-W-8 is part of a family of large flex brush seals that all fit the #7 large channel retainer. If 11 inches is more coverage than your application requires, the same product family includes a 3-inch brush (B3772-PP-W-8), a 5-inch brush (B3775-PP-W-8), and a 6-inch brush (B3776-PP-W-8) — all sold in 8-foot sections. Measure the gap at your door opening and select the brush size that provides full contact without preventing the door from operating smoothly.
Installation
Trim the 8-foot section to the required length using a standard utility knife or shears. Slide the flexible backing into the #7 large channel retainer mounted on the door frame, header, or jamb. The brush filaments should compress slightly against the door surface when the door is in the closed position. No adhesives, fasteners, or special tools are needed beyond the retainer channel. For new installations where no retainer is present, Barron Equipment carries compatible large aluminum retainers and mounting hardware.