Plywood bends can be used for a large variety of purposes, ranging from chair legs to decorative cupboards. Getting plywood to bend isn’t as simple as you might think, so we will be teaching you how to bend plywood using 4 different techniques: Kerf Bend, Steam Bend, Laminating Bend and Soaking Bend.
Always try to select plywood with little to no knots, as the knot can weaken the bend dramatically. Another thing you should focus on is to bend your plywood by following the grain, this is referred to as the “Strong way”.
As with any woodworking project, you will need some tools.
- Pencil – For your marks.
- Plywood – Choose your ideal plywood for your bends, Finnish birch is often recommended for bends.
- Circular saw – Kerf bend method.
- Large square or straight edge – To ensure your cuts are straight.
- Wood glue – Kerf bend.
- MDF – To create a form/template for your bends.
- Jigsaw/Band saw – Used for cutting long strips easily.
- Steam Box – For steam bend.
- Heavy Gloves – Protects your hands from steam and hot plywood scolding.
- Bar Clamps – Used to secure your plywood around a form.
- Polyurethane glue – Long setting glue for the laminated bend.
- Sander – For finishing your edges.
- Sandpaper – Required for final touches.
Bending plywood using the Kerf bend method is the fastest and easiest way to achieve a bend.
It involves cutting notches or grooves into the inside of your desired corner. The narrower the cuts, the smoother the curve will be.
- Cut a length of thick plywood into the desired dimensions for your bend.
- Using a ruler and pencil, mark out the area designated for your bend, this will give you a guide when it comes to sawing your notches – referred to as kerfs.
- Check your plywood for knots, a knot will drastically increase the odds of the bend failing.
- Use a circular saw, set to one half or one third of the depth of your plywood.
- With the help of a straight edge, cut a groove every 6mm between your cornering marks.
- Fill the kerfs (grooves) you have cut with a strong bonding wood glue, PVA will do fine but ideally you want a strong, slow setting glue for maximum bonding and strength.
- Bend the corner and secure using clamps, leave to set for over 6 hours. Once the glue sets, you have your bend ready for application.
Steam bending creates a strong dependable bend. As the bend follows the grain of the wood, it eliminates the weakness issues of a band sawn curve.
Just like all bending methods, choose a knot free strip of plywood.
- Cut a form using multiple layers of MDF until you reach the desired thickness for the bend. This will create a template for your plywood to follow when bending.
- Set up your steaming box and prepare for use.
- Once ready, place your plywood above the steam box, fixed with wire supports.
- Turn on the heat source and steam your plywood for 1 hour per 24mm of plywood thickness.
- Using heavy duty, heat resistant gloves, remove your plywood from the steam box.
- Immediately bend it over your form and attach with clamps to secure.
- Leave the plywood to dry for several hours.
- When your plywood has dried, loosen it from the clamps and you will have your bend.
Laminated curves are extremely strong bends, made up of 2 or 3 strips of plywood, glued together to create a reliable corner.
- As described above, build a form for your bend.
- Use a thin sheet of plywood, 5.2mm is ideal. Measure your plywood and cut multiple lengths until you have enough to reach your desired thickness.
- Stack your pieces together and precondition them by clamping them to the form, DO NOT USE GLUE YET.
- The first clamp should be place in the middle of the corner. Working from the middle, outward, attach more clamps as required.
- Keep adding more clamps until no space exists between your plywood and the form. It’s not uncommon to use 6 or more clamps for larger bends.
- Using a pencil, mark on your form where the clamps are, this will save you time later.
- Remove your clamps and keep them close. Your next move is to place all the strips onto a cloth, or butcher paper.
- It’s time to get gluing. Get your glue ready, a long setting glue like Polyurethane is recommended for maximum bonding and adhesion.
- Once glued, stick your strips together and re apply them to your form, make sure you don’t glue the strips to the form!
- Use the same clamping method as before, starting from the centre and following your pre marked clamp points. Excess glue will leak out of the joints, don’t worry about this now as we will clean this of later.
- Keep tightening the clamps until there is no visible space between your plywood and the form.
- Once clamped and ensuring there are no spaces between your plywood and form, leave the glue to set according to the instructions. Waiting time can vary depending on which glue you have used.
- When the glue has set, remove your plywood from the form by loosening the clamps.
- Remove the excess glue with a belt sander, this may take a little while, but keep going until your edges are smoothed finely.
- Depending on how strong of a sander you used, you may need to trim a few mm of your edge from your corner.
- Once finished use an orbital sander to fine touch your edges until you reach your desired finish. That’s all there is to it!
Soaking is another way to achieve a strong corner, it is best used for smaller work as you will need a huge water tank to soften an entire sheet of plywood.
- Start by cutting your plywood to the desired dimensions, you will only need one strip for this type of corner.
- When ready fill an appropriately sized water tank with water and submerge your plywood completely.
- Leave it to soak for about 2 hours, until the plywood has softened.
- While the plywood is submerged, use the time to cut and stack your form using the same MDF method as mentioned above.
- After a couple of hours, remove your plywood from the water tank.
- Make sure you bend the plywood along the grain, using the same clamping method as the laminated corner.
- Start from the middle of your corner and clamp your plywood to the form. Ensuring there is no space between your plywood and the form.
- Once you are happy with your clamp work, leave the plywood clamped and allow it to dry for a couple of hours.
- Once dried, remove your plywood from the clamps and you have a perfect corner for your project!
So there you have it! 4 different ways on how to bend plywood, now get out to the workshop and make those corners glide!