Different Types of Wood Adhesives

Wood adhesive or wood glue is the most important support material in woodworking and carpentry projects. It is an adhesive material for joining or bonding two pieces (or more) wood components together.

There are other materials such as nails or screws, but glue create the strongest joints and the cleanest connection. Today, there are many types of wood glue available with some advantages and disadvantages.

A worker is applying PvAc glue into wood components

You have to know the application area and your purpose in order to choose correct type of wood glue. Wood glue has different physical properties that will give impacts to your application. The drying time or curing time, level of strengths, viscosity, and water resistance level.

Drying time refers to how long the glue can be totally dried to create the bonds between pieces. Some glues take several hours to dry, some wood glue just takes a few minutes. To decide which one is right, you need to identify the process possibilities. Some joining process needs more time than the others because of its complexity.

1. Polyvinyl Acetate (PvAc) Glue

It is widely used in woodworking industries, some call it white-glue. It is waterbased glue commonly used for wood furniture manufacturing. This glue requires clean surface, free of dust and dirts. And as it is a waterbased, the glue will 'penetrate' into the wood pore and create a strong connection when fully dried.

PvAc glue needs longer time to dry, normally it takes between 10-16 hours to be completely dried before the next process. Although on some kind of joints, you can remove the clamp when it is 'touch dry', about 1-2 hours after application.
Using PvAc glue is very easy. Simply apply on both surfaces, connect both components, and you'd better clean up the overrun glue using a wet clothes or brush immediately. But be careful not to apply to much amount of glue, because it can create humid on the surface and you may end up with swelled wood or bending wood.

2. PolyUrethane (PU) Glue

Polyurethane is a synthetic plastic resin that is both water resistant and waterproof. Its bond is activated by moisture in the air, so it works well in humid environments. It's also called foam glue because it turns foamy. Once dry, this glue is in the form of foam, the harder the foam produced, the better the quality of the Polyurethane glue.

Polyurethane glues even works better when wood MC is above 20%, besides being a great fit for oily wood. The fact that water and oil don’t mix also applies to wood glues. This explains why PVA, water-based wood glues don’t perform well bonding oily woods whereas polyurethane glues excel in this area.

PU glues offer longer assembly times of up to 30 minutes, along with a short clamping time. That's why, polyurethane glues are the best adhesive for finger joints and lamination works.

The disadvantages of polyurethane glues is that they’re more toxic than other types of wood glue and they are more costly. They also are more difficult to clean up. But you can use a chisel or sandpaper when dried. Or you can proceed it again into planing machine.

3. Ethyl Cyanoacrylate glue

Cyanoacrylate (or CA glue) is a fast-drying acrylic resin with a tight and rigid bond. CA glue is the hobbyists’ name for what everyone else knows as super glue.

CA glue cures quite fast, in just a few minutes. Just apply the glue, then press the two wood pieces together, hold it for a few seconds, and the 2 pieces will be bond strongly.
You don’t need clamps to keep those 2 pieces as a tight bond. This glue does not provide the best quality to join 2 wood components, but it is the best option if you want to attach other materials such as ceramics tile, a pice of glass, or to strenghten metal attachment on a wood pice.

In term of functional, CA glue is good to use as a temporary bon when you dont have the tools to clamp, or when the use of clamps is not possible.

4. Epoxy Glue

Epoxy is a type of polymer with an incredibly high tensile strength which can range from at least 5,000 PSI to upwards of 10,000 PSI. Most epoxy resins come in two parts and must be mixed to activate. But once you mixed the 2 components, it cannot be re-use when you have left over.

Epoxy is waterproof and the cure times do vary by a wide range, about 20 minutes to one hour. Some other epoxies can even take days to cure.

Epoxies are most commonly used in woodworking to fill in cracks and voids, sometimes mixed with wood saw dust. Just mix some saw dust and epoxy together and rub it into any holes. You can do the same using other types of glues, but epoxy glue has better finish and easier to smoothened.

5. Yellow glue
Yellow glue have long been the preferred option in Indonesia, often known as "Aibon glue," is frequently used to adhere materials including HPL, plywood, rubber, leather and metal plate. Yellow glue contains organic solvents and synthetic rubber. Most common usage is to apply top layer of HPL on a plywood.

The application of this glue is easy, first you must clean the 2 surfaces of the object to be glued. After that, spread the glue on both surfaces and then let the glue dry. After 'touch-dry', you can start connect the two surfaces together.


Because wood is sustainable and more eco-friendly

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