LLPT BST342 Butyl Tape, 3/4-Inch x 33-Foot, Black, 2-Pack

Everyday use

RV owners and boaters looking to seal seams, windows, roof areas, or trim need a material that can follow the shape of the repair. LLPT BST342 butyl tape is a flexible, non-hardening sealing strip for indoor and outdoor projects. Its synthetic composite rubber molds around tight corners, curves, and uneven surfaces, making it useful for repairs where a pressed-on strip can trace the joint.

For a roof seam or vent edge, clean the surface, position the tape, and press it firmly along the area to be sealed. If your project calls for a molded strip around a window or a patch on metal roofing, the same tape can be shaped to fit. That differs from applying sealant as a bead: this format is a practical choice when you want to lay and form tape directly over a joint.

Product specs

• Type: Butyl sealing tape
• Size: 3/4 inch x 33 feet
• Color: Black
• Pack: 2-pack
• Material: Synthetic composite rubber
• Compatibility: Glass, fiberglass, wood, coated or uncoated metals, plastic, and rubber
• Application: Indoor and outdoor sealing and waterproofing

What stands out

The tape stays pliable rather than drying or hardening, so it can be molded around tight corners and unusual curves. Its flexibility also helps it conform to uneven or jagged surfaces, including joints where a rigid strip would be difficult to position. The manufacturer describes it as waterproof, elastic, and high-viscosity, with sealing uses that include blocking wind, water, dust, oil, grease, vapor, and moisture.

It can be used for window and door reinforcement, windshield and pipe sealing, mobile home repairs, and patching EPDM or galvanized metal roofing. It is also paintable, which can help create a more integrated finish at the installation area. Buyers commonly highlight the tape’s flexibility, ease of handling, and sealing performance. Feedback on adhesion and durability is mixed, so careful surface preparation and firm pressure are useful parts of the application.

For best bonding, clean the surface before applying the tape, then press it down around the full area. The recommended installation temperature is around 10 Celsius degrees, colder conditions can make the material stiffer and take more effort to mold.

When it makes sense

Choose this format for repair work where you need to shape a sealing strip along a seam, around a window, or over a roof joint. It suits varied materials such as glass, fiberglass, metal, plastic, wood, and rubber, giving it a range of uses across RV, boat, home, and roofing maintenance. The black, 3/4-inch-wide tape is a straightforward fit for projects where a flexible, non-hardening seal is more practical than a bead-applied product. It is especially useful when the repair follows curves or uneven edges and needs to be pressed into place by hand.