Polyurethane Glue

Overview

Polyurethane adhesives are the perfect adhesives for almost every DIY repair that does not involve extremes of environment.

The main types of polyurethane glue for outdoors use are designed for wood surfaces and those that can be used as construction adhesives. Indoor use typically is for metal, copper, plastic, ceramic and glass.

What jobs is it good for?

The thing to remember when selecting a polyurethane adhesive is that there are many variations. Some come in two part formulations much like epoxy, while others are similar to superglue. Some dry with a very hard surface and very high strength; others are aimed at joining rough materials together like stone and will expand to fill gaps.

I'll go more into the details of the different types in the detailed guide but for now the thing two to bear in mind is that this is the workhorse of DIY adhesives, but when selecting the specific brand its important to see exactly what application is intended for.

What jobs is not good for?

Polyurethane glue can be quite messy. In some respects is rather like epoxy. It also needs moisture as part of the curing process and so can't be used on very dry surfaces. In my experience it also tends to have a rather short shelf life - once you return to it six months later you'll find it to be a plastic clump.

How to use

This is one of those glues that you need to be patient with, taking as much as up to 40 hours to fully cure. Depending on the situation you need to find some method of holding the two surfaces together using a clamp or similar. I've often found using a heavy book has the same result depending on the application.

The curing process itself requires moisture and heat; the more heat and the more moisture present the faster and better it'll cure.

As with most adhesives it's always advisable to work in a well-ventilated area and if it does spill warm soapy water can be used clear up the excess. If you have it, acetone also works well