Finding the right glue for your project can be tough. There are a a lot of options out there to sift through and each brand has its own version of each type of glue. This post won’t go into all of the different types of glues, but rather, I’ll focus on two of the most popular types of glue on the market- wood glue vs polyurethane glue.
When you stack up wood glue vs polyurethane glue, you find two very versatile and powerful glues that should get you through just about any project you could need. They both have their strengths and weaknesses, and knowing how to use them and when to use them will make you a better carpenter or DIYer. Keep reading and I’ll lay out the advantages and disadvantages of each so that you can figure out what will work for you.
Wood glue, sometimes known as yellow glue, has been around for a long time and is a workhorse of the carpentry shop. It is very easy to use and bonds so well to wood that the wood around the glue usually fails before the glue joint does when stressed. It is simple to apply and requires very little skill to apply with success.
Advantages of Wood Glue
- Easy to Apply
- Longer working time of about 30 mins
- Very strong edge grain to edge grain connections on wood
- Certain varieties are waterproof and can be used outdoors
- Water cleanup
Disadvantages of Wood Glue
- Weak end grain connections in wood
- Can only be used on wood and wood products
- Certain varieties cannot be used outdoors or in wet conditions
Wood Glue is for exactly what is sounds like. Wood. If you are laminating wood pieces together for projects like butcher block counters, cutting boards, or simply trying to make a larger piece of wood then wood glue is the way to go. For bonding wood along its sides or faces, wood glue provides the strongest bond on the market and is easy to apply. Wood glue works best when applied to both pieces of wood and brushed to cover the entire surface. Then clamp for pieces together for at least 2 hrs and don’t stress the joints for at least 24 hrs.
Make sure you find the right kind of wood glue that fits your needs since there are a lot of manufacturers with a lot of different products out there. My preference is Titebond and I’ve written a post comparing their three types Titebond I, Titebond II and Titebond III and when to use each. If you decide that wood glue is right for you, then check out that post.
Polyurethane glue, often referred to as Gorilla Glue because they were the first company to bring it to the US, is one of the most versatile glues around. Unlike wood glue, polyurethane glue can be used effectively on a variety of substrates like wood, stone, metal, ceramic, foam, glass, concrete, and lots more. There are very few materials you can’t glue back together with polyurethane glue.
Advantages of Polyurethane Glue
- Extremely versatile
- Expands to fill joints
- Very strong end grain connections on wood
Disadvantages of Polyurethane Glue
- Requires moisture to cure
- Expands to fill joints
- Shorter working time of about 15 mins
- Clean up requires paint thinner
- Short self life of 1 year
One of the tricks of polyurethane glue is how it cures. It requires moisture to cure rather than air drying like wood glue. That means that you’ll need to mist both surfaces lightly before applying the glue for a good bond. Unlike wood glue, polyurethane glue excels at connecting end grain joints, so keep that mind as well.
You may also have noticed that I listed “expands to fill joints” as both an advantage and disadvantage. That’s not a mistake. That expansion makes polyurethane glue an excellent choice for uneven, irregular surfaces. It also poses a challenge when gluing two smooth surfaces together because if not clamped properly, that expansion can push the surfaces away from each other.
Comparing wood glue vs polyurethane glue, you have a working time about half that of wood glue with polyurethane. For little projects this might be helpful, but for larger glue-ups, this usually causes problems.
Which Glue is Best?
The answer is neither, or rather…both! They are different glues with different strengths and weaknesses like I said earlier, and in my shop, I have need of both. Just like your tools, your hammer isn’t better than your screwdriver, they just do different things. And while they may both be glues, they are worlds apart in how I use them.
For the random things that break around the office and any end grain carpentry projects, polyurethane is my go to glue. When I’m laminating lumber, gluing dutchmans in place, or any other woodworking other than end grain connections, wood glue is the right choice for me.
I recommend you have them both in your shop. Buy a big container of wood glue and a smaller one of polyurethane to avoid it expiring and then use them for the jobs they were intended for and you’ll be a better craftsman for it!