How to Glue Metal to Wood and Which Adhesive is Best
If you’re working on a project that requires gluing metal to wood with hot glue and a hot glue gun, you probably figured out that it’s not exactly the easiest thing to do. The good news is that, with the right technique and the right adhesive or epoxy, you have a great chance of long-term success.
What Adhesive Should I Use?
There are a few different products that are great for gluing wood to metal. They are:
The good thing about this cement is that is doesn’t bond instantly. You actually have about five minutes before it starts to set so there’s a little time to make any necessary adjustments. It takes anywhere from 24 to 72 hours to cure. This adhesive is temperature-resistant, flexible, and waterproof once cured.
This is a super strength formula that’s great for heavy objects. It’s resistant to moisture, harsh chemicals, and maintains a stronghold in freezing temperatures. Plus, it bonds in seconds and dries clear.
- Professional-strength ingredients work fast and hold strong
- Fast-setting formula resists moisture, most chemicals and cold temperatures
- Pinpoint nozzle allows precise application without dripping or oozing
- Screw-on cap cleans and seals nozzle for clog-free use
- Loctite Super Glue Professional's super strength formula is ideal for heavy-duty projects and repairs.
This glue from Elmer’s is really strong, dries clear, and is non-toxic. It’s also non-foaming so there’s no expansion like so many other popular adhesives. It has a 20- to 30-minute clamp time and bonds in 24 hours. When it dries, it’s 1005 weatherproof, translucent, and can be painted.
- Professional-strength, all-purpose, and multi-surface glue
- Bonds metal, glass, ceramics, wood, stone, concrete, and more
- 100% weatherproof, non-toxic, no foam, and less mess
- 4-ounce adhesive bottle
- Elmer's: The Glue with the Orange Cap
The Importance of Clamping and Cleaning
Obviously, the adhesive you choose is very important in a project like this but something that’s equally important is effective clamping.
Clamping is essential because it holds the materials together to make sure the surfaces fully bond and that there is no air in between them. Air trapped between the two pieces will expand and contract which will eventually cause gaps. This allows moisture to get in which will absorb into the wood and eventually break the bond.
It’s also very important to make sure that both surfaces are as clean as possible. The wood should be free of any dust and debris to ensure the best possible bond. Anything left behind creates a gap which will eventually lead to other problems.
Metals are often treated with oil so be sure to clean it using denatured alcohol to get it as dry as possible. Any oil left behind will prevent a proper bond from forming.
In order to get the job done properly, you’ll need to gather your supplies before you get started. Here’s what you’ll need.
- Brush to clear away dust
- Clean rags
- Denatured alcohol
- Utility knife
- Small trowel
- Small roller
- Thin piece of small plywood
- A few 5-gallon buckets filled with sand or something to use as a weight during bonding
Here’s a step-by-step guide to help you glue wood to metal properly. Please keep in mind that this is a general guide that’s applicable to most situations but you should always follow the directions on the adhesive you’re using closely as that’s one way to make sure you’ll get good results.
- To ensure a proper bond, the first thing you have to do is prep the wood. If necessary, sand the side that is going to be bonded to the metal. You should use a heavy grit sandpaper to rough up the surface which will ultimately lead to a stronger bond. The rougher the surface is, the more surface area is available for the adhesive to hold onto.
- Use a brush or rag to wipe the surface of the wood to remove dust and debris. The surface should be as clean as possible. Anything that gets in between the wood and metal will affect the bond and leave an air pocket.
- Clean the surface of the metal with a clean rag and denatured alcohol. This removes dirt from the surface but, more importantly, it removes any oil. Oil drastically reduces the effectiveness of any adhesive so this step is really important. You can also, optionally, rough up the metal with some sandpaper or a file.
- Place the metal and wood next to each other with the clean sides facing up. Double check that you’re working with the right side because it’s not easy to make changes once you’ve already applied the glue.
- Prepare the adhesive. This step varies depending on what brand you’re using. Follow the directions carefully when preparing and applying the glue.
- It’s best to start by applying the adhesive to the metal first. Make sure you’re using the cleaned side and begin by running a bead of glue around the perimeter of the metal, about a half inch from the edge. Once you have the perimeter outlined, place a long line of adhesive zigzagging across the interior surface. Use a trowel to spread the zigzagged adhesive around, leaving the bead of glue around the perimeter intact.
- Place the side of the metal with the glue to the wood. Use the roller across the entire surface to work out any air bubbles starting from the center and moving outward.
- Now you’re ready to clamp. Place the smaller piece of plywood over the metal. This is to prevent the clamp from digging into the surface of your project. Space the 5-gallon buckets or suitable weights over the surface of the plywood. Then, clamp the edges of the metal to the wood to hold everything together.
- Clean up any glue that oozes from between the pieces being very careful not to get any on the surface.
- Leave the clamps and weights in places for the recommended time according to the adhesive instructions. This is usually around 24 hours but can be as long as 72 hours.
- Remove the clamps, buckets, and plywood once the adhesive has cured, wipe down the surfaces, and you’re done!
Take Your Time
As you can see, gluing metal to wood is time-consuming but if you want to create a bond that last, it’s important to do it right. Remember, the two most important factors for how well the glue will hold are the quality of the adhesive and clamping. One really does rely on the other.