If you are building anything out of wood, at some point you will use PVA glue. I use it all the time. You know that big jug of yellow glue you have sitting around your shop? That’s it.
Knowing about PVA glue is relevant for most woodworkers because it is a substance that they will use over and over on their projects. It is important to know why you are using a certain material instead of another.
For example, if you know that carpenters glue actually performs a certain task better than something like Gorilla glue or super glue, then you will want to use it instead. And vice versa.
Technical Details
Wood/carpenters glue, Elmer’s glue, bookbinding, drywall primer, and envelope glue are all PVA based glues. PVA stands for Poly(vinyl acetate).
It is a polymer, meaning that it is a large molecule that contains many monomers. A monomer is a molecule that can bind chemically to other molecules. It does this through the process of polymerization. Polymerization occurs through a chemical reaction.
Polymers have certain characteristics that make this type of glue ideal for tasks such as book binding. It is tough and viscoelastic, meaning it can handle some flexibility without being deformed.
PVA glue is an emulsion of the polymers in water. As a result, it is water soluble and easily cleaned with warm water and soap.
What is PVA Glue used for?
PVA glue works best on porous materials such as wood, paper, and sandstone. A variety of applications, from construction to crafting, require PVA glue. It is especially useful for us because we are building things with wood.
There are several different specialty glues within the PVA family. This is why you wouldn’t want to use Elmer’s Glue to glue up a table top or use carpenters glue for a book binding.
Here are some usage examples:
- Elmer’s glue is good for crafts and projects – schools use it all the time for this reason.
- PVA glue seals and dust proofs porous surfaces such as cinder blocks.
- Bookbinding glue will normally be clear or white. It is pH neutral.
- Envelope Glue
- Wallpaper Glue
Woodworking
For woodworking there are a few different types of PVA glue. Usually you will see yellow and white.
Yellow is usually used for outdoor applications. Carpenter’s glue is an example of that type of glue. Any wood based application can use this type of glue. It is not water-proof, but it is water resistant. It can withstand a little bit of moisture before it begins to breakdown.
White wood glue is good for more fine woodworking applications. Here are some pros and cons of wood glue:
Pros:
- Fast-drying
- Water soluble for cleanup
- Very strong wood joints
- Inexpensive for large quantities
- Good shelf life
- No dangerous fumes or hazards – you can easily handle this with your bare hands
- Neutral pH
- Only toxic if you eat it
- Can dilute it by adding water to the glue – this is useful for projects where you need to spread it out more or wash it over something
Cons
- Not fully waterproof
- A few different algeas and other types of fungi will break it down
- Not super fast drying time like some super glue – needs about 24 hours
How to Use Wood Glue
Using wood glue is relatively easy, but there are some techniques that can help make your life easier. It can be difficult to clean up if you use too much and it leaks out onto other surfaces. It is especially difficult to clean up if it has dried.
Once the glue has dried, your only real option is to sand it off. Maybe you can scrape some bigger drips off.
Here are some helpful tips for when you go to glue up some wood:
1. Prepare Workspace
Once you start pouring some glue around things can get messy and out of hand if you’re not prepared. You should take some steps to prepare the work area.
This means having room to maneuver your boards around without knocking other things over.
Cover any table top surfaces that you don’t want glue on with craft paper. This will allow easy cleanup from drips that are likely to occur.
Make sure to have all of your tools accessible that are needed. This leads me into point number 2.
2. Use the Right Clamps for the Job
Normally when glueing a joint together you will want to use a clamp. There are many different types for woodworking.
Generally some pipe clamps will work well for glueing up a table top. A spring clamp and bar clamp are two others that beginners need to get started.
I will make a page later on about the best clamps for the job. For now I will link to here and here for more info.
3. Right Conditions
Make sure that your environment is suitable for using the glue. This means having a well ventilated area.
The temperature should be 50-80 degrees Fahrenheit, although that is not a requirement. Usually the glue will function as normal between 30-100 degrees; the drying time and consistency will just change.
The humidity is also a factor, but generally it is not something you should be too concerned with.
After glueing some projects together a few times you will begin to get a feel for what works and what doesn’t as far as conditions go.
4. Clean Up Well
Wood glue can be a pain to clean up once it is dried. If you take your clamps off the next day and realize that glue has dripped on your project, then you will have to get the sander out.
Sometimes there are large drops that you can chisel off, but sanding it is really the best way to get it off completely.
Avoid this problem altogether by taking the time to keep your project clean and tidy. As you glue it up have a wet rag nearby to clean up excess glue.
Don’t use too much glue to start off with as well. That will help prevent having excess glue squeezing out of the joint as you clamp it together.
Conclusion
PVA glue is used in a number of applications. For our purposes we are only concerned with wood glue. There are a few different types of wood glue that you will see at the store. I recommend experimenting with these different types and find what you like best.
For more tips on beginner woodworking check out my Get Started page. It has several more woodworking 101 articles that can help answer some questions that you may have. It will also help you build some more skills.
For some projects to get started on have a look at these projects.