Bondit PU18 Polyurethane Adhesive & Sealant – Expansion Joints

Bondit PU18 is a one-part, moisture-curing polyurethane adhesive and sealant built for expansion joints in construction, engineering, automotive and marine applications. If you need a PU18 expansion joint sealant that bonds well, moves with the joint and stays put through temperature cycling and vibration, this is a practical, well-proven choice. One-part means no mixing, no waste and no mess from getting the ratio wrong at the end of a busy day.

The product cures to a tough, elastic seal with a Shore A hardness of 40. That sits in a useful middle ground: firm enough to resist mechanical damage and foot traffic near joints, but flexible enough to accommodate the movement you expect in expansion joints across concrete slabs, panels and similar structures. The elasticity is not just a nice-to-have here. It is doing real work every time the structure expands, contracts or takes a load.

Where Bondit PU18 Gets Used

On site this sealant earns its place sealing movement joints in concrete floors, cladding panels, precast elements and masonry. It performs just as well in the engineering sector, where oil resistance and vibration damping matter. The automotive and marine trades use it where a sealant needs to cope with exposure to oils, fuels and constant movement without breaking down or losing adhesion.

Adhesion and Compatibility

Adhesion is one of the stronger points of PU18. It bonds to concrete, wood, metals, GRP, most rubbers and the majority of common building materials without requiring a primer in many cases, though priming is always worth considering on porous or contaminated surfaces. It is also suitable for fixing wooden floors, which is a useful secondary application when you already have a cartridge open on a refurbishment job.

CE approved and available in black, grey and white, Bondit PU18 suits both structural and aesthetic requirements. It works in a standard 310ml cartridge, so any competent applicator gun handles it without fuss.