All-purpose for PU

Polyurethane glue: A beginner’s guide

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If you’re looking for a versatile bonding solution that’s compatible with multiple materials, it’s worth checking out Loctite’s guide to polyurethane glue.

Polyurethane glue: What is it?

Here’s the science bit: first created in Europe in 1937, polyurethane is a polymer composed of units of organic chains connected by urethane or carbamate links. Most polyurethanes are thermosetting polymers, so they set when heated.

In the case of polyurethane adhesive – also known as PU adhesive – this means that the liquid glue will become rigid when exposed to air at room temperature. When polyurethane adhesive sets, it absorbs the energy in heat to power a chemical reaction and create a very high strength bond.

What can you use polyurethane adhesive for?

As well as forming a strong and long-lasting bond, polyurethane-based adhesive is also incredibly versatile, making it a good choice for those needing an all-purpose adhesive that is flexible, relatively quick to set and suitable for non-porous as well as porous materials. Polyurethane glue can be used to bond wood, metal, leather, tile, glass, rubber, brick and concrete. It isn’t effective with plastics like polyethylene, polypropylene and chemically-created materials like Teflon.

Polyurethane glue is available as a one or two-part adhesive. The one-part adhesive will take up to half an hour to set, giving you plenty of time to reposition, while the two-part will set more rapidly.

Polyurethane glue: Advantages

  • Can be used to glue non-porous materials together, such as mirror to walls or wood to metal.
  • Sets in high moisture conditions and is waterproof.
  • Very easy to sand and cut away unsightly excess adhesive.
  • Suitable for application outdoors as well as indoors – as well as being waterproof, PU adhesive has good UV resistance.
  • Can be painted and stained after it has set.