Joining wood together (joinery) is necessary for loads of purposes in life. It’s not something reserved for professional woodworkers or other tradesmen.
And when you need to join wood, and wish to achieve an excellent, durable result, you need to use a quality wood glue that’s best suited for the application at hand.
Continue reading to learn about the different types of wood glue on the market, the factors that dictate how fast wood glue dries, and how long you should wait after applying it to sand it.
And no worries, like always, we’ll keep it fresh, educational, and fun!
Understanding the Different Types of Wood Glues
Polyvinyl acetate (PVA) glues are the most common type, and there are quite a few different glues that fall into this category, including good old-fashioned white glue, like Elmer’s. And while any given woodworker is sure to have a favorite type of wood glue they reach for regularly, some projects will require other types.
While it may seem trivial to most, the choice of which wood glue to use matters in terms of achieving a professional-grade result that will perform well for many years. Choosing the wrong type of wood glue for your application can yield inferior results that don’t look, perform, or endure well = no good!
Some of the better known types of wood glue you’ll find on the shelves include:
- Gorilla Glue: This popular brand of glue is polyurethane-based and is manufactured as an all-purpose adhesive, not simply a wood glue. Like other polyurethane glues, Gorilla Glue is moisture-activated, which means it’s a good choice when working with high-moisture woods. According to International Timber, when wood moisture is high, these glues tend to foam up and expand out of joints.
- Cyanoacrylate Adhesives: CA glues are typically referred to as the brand name, Superglue. This is actually a category of adhesives that work well on a variety of substrate materials. Cyanoacrylate adhesives set very quickly, so you have to have a good plan and stay organized when working with them. Gel versions are good choices for gap fillers, and can also be used to form a hard-shell, self-leveling finish.
- Epoxies: While not widely thought of as wood glues, epoxy resins can join wood together excellently. They are especially useful when working with gapped joints because of their high solids content. Epoxies have superior tensile strength and can be used to achieve a high-sheen, hard finish coat on wood.
- Contact Cements: Surfaces coated with these highly tacky adhesives bond together instantly. They have many uses but are widely used for applying veneer. Be careful when working with contact cement as it is completely unforgiving. Once it grabs, it is difficult to reverse without damaging the substrate.
- PVA Glues: The most popular PVA adhesives are Titebond, Titebond II, Titebond III, and Titebond Extend. Titebond I and II are yellow PVA glues with lower water content than white glues like Elmer’s. Water content matters to woodworkers because more water can cause warping and decrease gap-filling capability. To put it in perspective, yellow PVA glues fill gaps better than Elmer’s and other white glues – but not as well as some other adhesives, like epoxies, for instance.
- Titebond III is like I and II, except it has the added feature of being waterproof. And finally, Titebond Extend is a slow-setting version, which is useful in applications where complex clamping set-ups are needed, as it allows you longer to clamp all pieces in place for optimal positioning.
Now, before we learn about how long it takes wood glue to dry before it’s good for sanding, let’s do a quick recap about the importance of clamping. I mean, you aren’t going to have very good results with your wood gluing projects unless you have a way to hold the wood in place as the glue dries.
It’s OK – I’ll make it fast and easy!
Proper Clamping Is Imperative
Doing a good job clamping wood together is an integral aspect of every successful glue-up, maybe even more important than the kind of glue you choose to use. Effective clamping accomplishes three nice things for the woodworker, including:
- It holds the wood pieces in proper orientation with each other
- It maintains the positions of all pieces as the adhesive dries
- It closes gaps, negating the need for glue to span them
When clamping, try to ensure that all gaps are closed. Different clamps provide different forces. Some are easier to use in a given application than others.
So, I recommend keeping loads of different clamps in your workshop. They’re relatively inexpensive, are super useful, and last for years and years.
PRO TIP 1: Dry clamp your pieces together before gluing them. It’s really smart and helps to avoid mistakes during a glue-up. Also, if you have a complex clamping set-up, give a little consideration to the precise order you should apply the different clamps when actually gluing.
You don’t want to encounter a situation where you have already glued a piece, and then realize you should have glued another first.
What Affects Wood Glue Drying Time?
There are several factors that can affect the amount of time it takes wood glue to fully dry, including:
- Wood Type
- Moisture Content
Let’s look at each.
Humidity is moisture in the atmosphere. High humidity will typically make glue take longer to dry out (dehydrate). Low humidity will help wood glue to dry faster.
Wood glue dries faster when it can soak into the pores of the substrate it’s applied on. So, if you have a non-porous wood that doesn’t absorb well, the drying process will take longer.
The temperature in the space where your glued wood is drying matters. Too cold or too hot temps can affect both the drying time and the strength of the bond created.
Extreme temperatures can cause the glue to not dry and cure appropriately. Always read the directions on the glue product you’re using.
Wood Moisture Content
The amount of moisture in a piece of wood also affects its capacity for bonding and how long it takes wood glue to dry on it. Higher moisture wood will extract less moisture from the glue, making it take longer to completely dry.
PRO TIP 2: Whenever I clamp and glue wood pieces together, I turn the heat up to about 80 and run a box fan. That keeps the air warm and circulating, which does a lot to speed up curing and achieve a professional, tight result.
I also plan every move so that I am in no hurry for the glue to dry. I always give it extra time so that I know for sure that the glue has dried 100%. (More on that below.)
How Long Should You Wait before Sanding Wood Glue?
OK – here we are, finally to the point of the post: How long should you wait for wood glue to dry before sanding it?
Well, first, always read the application and curing instructions on the wood glue product you use. Take a minute or two to thoroughly read all the instructions, because, sometimes, there’s actually useful info there. You know the old saying, if all else fails, read directions!
After you have your workpieces glued and clamped, leave them in a warm, well-ventilated, and well-circulated environment. Most wood glues begin setting up rapidly, and many of them form what initially may feel to be a strong bond within 30 minutes or so.
But what’s the rush?
Most people I have ever known are not professional woodworkers with tight production schedules to meet. Nope, not the case! Most are people like you and I who may need to glue some wood together here and there throughout life, but it’s not something we do often. Right?
If you start testing your glued joints too soon, you’ll likely disrupt their positioning and the curing process, many times, leading to an inferior glued union = not the goal.
Patience is definitely a virtue when gluing wood pieces together. I highly recommend that you approach each project, allowing at least a full day of drying time, with the fan running in a warm environment.
Trust me, it’s always better to grab your glued-up workpiece and FEEL the rigidity of the glued work. You know when it’s tight and right – and it means that you did excellent work!
Thanks so much for reading along and I hope the information helps. And please remember to ensure proper ventilation and respiratory protection when gluing and clamping wood!