How to glue wood

Dozens of glues claim to work well on wood and a variety of other materials. But regular wood glue is the best wood glue for raw wood-to-wood joinery. Most wood glues are a type of polyvinyl acetate (PVA wood glue). Also sometimes called carpenter’s glue, wood glue is formulated to penetrate wood fibres, making glue joints that are stronger than the wood itself.

Yellow exterior glue (sometimes grey)

Yellow exterior glue is used for outdoor projects but not continuous submersion. It will be labelled water resistant or exterior.

White and yellow interior glue

White and yellow interior glue is the most common, workhorse wood glue, but it’s not for outdoor use.

Liquid hide glue

Use it for furniture repair; very long open time for assembly – up to 30 minutes. Requires a long curing time.

Polyurethane glue

Use it when you need a completely waterproof glue. Also glues metal and some plastics. Long open time for assembly – up to 15 minutes; curing time: up to five hours.

Epoxy

Use it when you need to fill gaps and for great strength. Comes in two parts that must be mixed just before using. Epoxy will glue most materials, and it’s waterproof. Won’t wash off your skin – or anything else.

Learn more about glues and adhesives.

Wood glue can last for years. But you may have heard that PVA wood glue goes bad after freezing or sitting around for a long time. The truth is that it might still be OK. Try stirring it with a stick to mix all the glue particles (don’t just shake it). If it’s a little thick, add some water – up to 5 percent. If glue flows freely from the bottle and feels slippery between your fingers – not stringy or clumpy – it’s probably OK to use. But if in doubt, throw it out. It’s not worth taking the chance.

Learn 22 cheap ways to make stuff last longer.

Wood glue brands recommend clamping an unstressed joint for 30 minutes to an hour. Stressed joints need to be clamped for 24 hours and it’s recommended that the joint not be stressed for at least 24 hours. For polyurethane glue, it is recommended that you clamp for at least 45 minutes.

Don’t miss our essential guide to clamps.

If your carpentry project might get wet, use glue that stands up to water. Glues labelled ‘water resistant’ are fine for things that’ll only get wet occasionally. For most outdoor projects, however, choose ‘waterproof’ glue, which comes in both PVA and polyurethane formulas. Both types are plenty strong and stand up to the weather, but polyurethane glue has the added benefit of being able to bond materials like stone, metal and glass. It’s messy stuff, though, so wear gloves while using it.

Learn more about how to choose the right adhesive for the job.

Finishing the parts of your project before you assemble them can be a great time-saver and allow you to get a better-quality finish. But for a strong glue joint, you have to keep the joints free of finish (glue doesn’t stick to varnish or stains very well). The solution is to apply masking tape to the surfaces that will be glued. Then remove it to expose raw wood when you glue up the project. Any good-quality masking tape will work. If you’ll be using a water-based finish, you’ll get the best results with a “no-bleed” tape such as ScotchBlue painter’s tape.

Check out these 5 masking tape hacks that will make your DIY easier.

Flux brushes, available in the plumbing department of hardware stores and home centres, are just right for applying and spreading glue. They work especially well for gluing intricate joints like the ones in the coped door rail shown here. You can store a wet brush for a few days in water and then wash and use it over and over again.

When you use steel bar clamps or pipe clamps, and wood glue comes in contact with the clamp, the moisture in the glue can cause the steel to leave a dark mark on your wood. Lay a sheet of wax paper over the clamps to prevent this “dark spot” problem. It will also catch glue drips that would otherwise get all over your clamps and workbench.

One good way to ensure a strong glue joint is to use the ‘rub joint’ method. Simply apply glue to the edges of one or both boards and rub them together to help spread the glue evenly before clamping.

When you’re gluing several boards together, it can be difficult to get all the top surfaces perfectly aligned. Here’s a tip that solves the problem. Rather than glue and clamp all the boards at once, add one board at a time. Let the glue joint set for about 20 to 30 minutes, then release the clamps and add another board. This method will take a little longer. But it makes it a lot easier to keep all of the boards’ top surfaces flush, which makes for much easier flattening and sanding of the surface.

Of course you reach for a superglue (cyanocacrylate glue, or CA) to fix a broken teacup handle. But did you know that it works on wood, too? In fact, CA glue is really handy for attaching small trim pieces that would be hard to clamp. Just put three or four drops onto the parts and stick them together. We like the gel version of CA glue because it doesn’t run off and make a mess.