Thermwell R538H Black Foam Tape 3/8x5/16 10 Ft

Product Description

The THERMWELL R538H is a black, high-density, self-stick foam tape designed for sealing, insulating, and weatherstripping applications in residential and light commercial settings. Measuring 0.375 inches wide by 0.3125 inches thick and 10 feet in length, each roll delivers a compressible, adhesive-backed seal that conforms to irregular surfaces. The high-density foam construction resists compression set over time, maintaining an effective barrier against air infiltration, moisture, and dust. HVAC technicians, plumbers, and general contractors reach for this tape when sealing gaps around ductwork, pipe penetrations, doors, windows, and equipment access panels where a conformable foam seal is required.

This foam tape is suited for use in draft-sealing, vibration dampening, and gap-filling tasks across a wide range of trade applications. Common install scenarios include sealing around HVAC unit panels, insulating around refrigerant line sets where they pass through walls, reducing rattles on sheet metal ductwork, and weatherstripping door frames or access hatches. The self-adhesive backing speeds up installation without requiring additional fasteners or adhesive products. It is sold in a package of 24 rolls, making it practical for stocking service vans or supply rooms.

Key Features

• High-density foam construction resists long-term compression set for a lasting seal
• Self-stick adhesive backing for fast, tool-free application to clean surfaces
• Black color blends with dark equipment panels and ductwork interiors
• 10-foot roll length provides adequate material for most single-opening sealing tasks
• 0.3125-inch thickness fills moderate gaps while remaining compressible under closure pressure
• Sold in a 24-roll package for multi-job or supply-room stocking

Compatibility

Designed as a general-purpose weatherstripping and gap-sealing tape suitable for use with HVAC equipment panels, ductwork, plumbing penetrations, door and window frames, and other surfaces requiring a compressible foam seal.

Installation Notes

Surface must be clean, dry, and free of dust or grease before applying the adhesive backing for proper adhesion. Press the tape firmly along the entire length of the sealing surface to activate the adhesive bond. When used around energized HVAC equipment or electrical enclosures, de-energize the unit at the disconnect before accessing panels. Cutting to length with scissors or a utility knife is recommended for clean, accurate fits at corners and joints.