Bent Laminated Bench From a Sheet of Plywood

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About: I'm a DIYer and creator likes to build, capture, and share my creations. Thanks for watching! Zach aka The Cutting Bored

Intro: Bent Laminated Bench From a Sheet of Plywood

The Modern Maker Podcast put out a challenge to create something cool from one sheet of plywood, so I got to work designing something in the bent-lamination category. Below is a video to the project, followed by a full tutorial. Hope you find the content entertaining and the project fun!

Step 1: Gather Materials and Get Stoked!

Below is a list of everything I used - hope this is helpful!

MATERIALS

  • 1 x 4' x 8' x 1/2" sheet of plywood (higher quality to avoid delamination)
  • 1 x 2' x 4' x 1/3" sheet of MDF
  • Scrap melamine
  • Titebond slow curing glue

TOOLS

FILMING EQUIPMENT

Step 2: Making Strips (lots of Them!)

My project called for 2 pieces of 1" thick, 2' x 4' plywood - the denser the laminations, the better (Pic 1). Instead of buying one large sheet of plywood and ripping it down, I skipped this step and bought 4 x 2' x 4' x 1/2" thick pieces and just laminated two of them together

In Pic 2, I glued them up and used all the heavy things I owned to clamp them together. Once they cured, I moved over to the table saw to rip them into 8 smaller pieces to make the more manageable (Pics 3-4).

Next came the tedious process of ripping strips. In Pics 5-6, I took all 8 pieces that I had initially ripped, moved the fence in 1/4" inch, and then ripped a very skinny strip. I repeated this process 15 times, removing 1/4" in at a time from each piece of wood (1/8" was lost to kerfing, while the rest resulted in a cut 1/8" thick). I ended up with 120 of these strips. If I had a drum sander, I'd have passed all the strips through it at this point to make them all the exact same thickness.

Step 3: Preparing Your Mold

Next was prepping the mold. I took a 1/2" sheet of MDF, ripped it in half (Pic 1), and then glued it together (Pic 2). I designed a template in Illustrator and printed it out to scale. I taped it together, cut it out (Pic 3), traced it onto the MDF (Pic 4), and cut it out with a jigsaw (Pic 5).

My jigsaw work left something to be desired, so I cleaned up the cut with a belt sander (Pic 6). Then, using a speed square, I traced a line 3 inches in on the curve of the mold (Pic 7) to provide a uniform spot for holes to be drilled later on. I counted my clamps (Pic 8), and determined how many holes I could cut. Using a large forstner bit (large enough to accept a clamp head), I drilled holes one by one (Pic 9). Pic 10 shows how all 15 or so holes were cut into the mold. You'll see how it comes together in the next step.

Note - this took a while and was tiring. I need a drill press. Also, the amount of MDF I bought was based purely on my design, and in hindsight, I wish I could have designed a more extreme curve.

Step 4: The Big Glue Up!

I used a large piece of melamine I had on hand as my flat surface. In order to avoid a mess and extra sticking, I laid masking tape (Pic 1) on the surface, including the edge of the mold. This is cheap and very effective.

I wanted to do this entire glue up at once - which was ambitious. Tite Bond has a slow curing glue - around 45 minutes - that allowed me to glue up 12 sets of 5 strips at a time (Pic 2-3) without worrying about things drying before clamping. Overall, this took about 33 minutes using a roll on glue bottle.

Then, one by one, I added clamps and slowly tightened things (Pic 4) until I got to a very solid tight glue up (Pic 5). I also used cauls on the sides to keep things flat - this is pretty much a necessity, otherwise you won't get a good flat glue up.

Once all the curved pieces were glued up, I also glue up strips of 5 and strips of 3 that were straight to serve later as legs and spacers, respectively.

NOTE - let this cure overnight - it needs to set properly for the lamination to work. Use cauls whenever you can to keep things flat, and make sure you are careful that when you make a single lamination (in my case, it was 5 strips), that your outside pieces of each strip don't have glue on their outsides so that each of your overall strips (5 total) don't stick to others.

Step 5: Admire Your Hard Work

After 12 hours, have fun breaking apart the mold, removing all the clamps and checking out how well your lamination came together. If it goes correctly, you should have no spring back. I was so excited at this point! One tip - keep your piece is in order (or at least labeled) for how you glue them up. Not everything is uniform, and it helps to keep things in the same order when you do the final assembly.

Step 6: Plane, Cut, and Prep for Final Assembly

After the glue up, I planed everything down to a uniform thickness. This was less about remove material and more about remove glue as I wanted to preserve thickness. I did this for my curved pieces and my straight pieces in groups of 5-6 to speed things up (Pic 1).

I switched to the miter saw to cut my legs and spacers to length out of the straight pieces, starting with cleaning up the outside edges of each piece (Pic 2)

For cuts, I did the following

Legs (5 strips thick)

  • 22 x 14" pieces

Spacers (3 strips thick)

  • 20 x 3.5" pieces (top spacer - Pic 3)
  • 20 x 2.5" pieces (bottom spacer)

One step I don't show is that each spacer (top and bottom) needed to be the same thickness to make spacing things uniform, so I cleaned up pieces on my stationary bench sander and then labeled them so pieces were not mixed up (Pic 4) - this will make sense on the next step.

Step 7: Leg Assembly

As you can see, each leg has three pieces - the 14" piece a 5 strips wide, the 3.5" piece at 3 strips wide, and the 2.5" strip at 3 strips wide.

This gave you a leg with spacers. The top spacer should over extend the leg by the thickness of the curved strips (Pic 2)

Step 8: Final Assembly

I used a quick grip clamp to clamp the pieces together, and then a speed square to square off each size of the piece (Pic 1). This gave me a reference line for the final glue up of the legs.

To do the glue up properly, I used the slow cure Tite Bond again and put 3" thick spacers between each piece, then squeezed it all together using the same quick grip clamp. By doing so, it gave the piece enough tension/friction that I could glue up and insert each leg in between the curved pieces, and they would hold properly until I could go back and clamp things up (Pic 2).

Pic 3 shows my exhaustion after that daunting clamp process (so many angles and cauls haha).

Step 9: Finishing Up!

The next day, I used my circular saw (Pic 1) to trim off the excess of the bench, followed by belt sanding at 80 grit (Pic 2) to flush everything up and remove as much burn as I could from the planer/saw, then final sanding with an orbital sander at 120 grit (Pic 3).

Not shown is me hand sanding the edges at 120 to just break them a bit (and not be so sharp).

Step 10: All Done!

And then I was done! And wow what a project! This is by no means perfect, but it is also very damn close to the vision I had for this project. I still haven't added a finish to it, but thinking about going a walnut color and sitting this in our garden as a statement piece.

NOTE - this thing isn't very sturdy and I didn't intend it to be - this was purely an experiment and I'm stoked to do something like this down the road.

If you want to know any materials, tools, or have any general questions answered, you can check out the second step or contact me via my website, thecuttingbored.com and I would be happy to do answer them.

As always, thank you for reading!

I would be so grateful if you could please subscribe to my Youtube Channel for future projects.

I put out videos every few weeks.

Cheers! Zach

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    11 Discussions

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    bruster999

    2 months ago

    Very nice!

    How did you get the plywood to bend like that without soaking or any other softening? Was the wood dry when you clamped it?

    Thanks.

    3 replies
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    charlessenf-gmbruster999

    Reply 2 months ago

    With Plywood, the grain alternates roughly 90 degrees with each layer, thus about half of the thickness of any strip, has the grain running perpendicular to the length of the piece thus amenable to such a bending.

    The Design is an unfaithful copy of one done using solid wood (Oak?) strips which is a very old approach to 'curving' wood forms that offers the benefit of greater strength than might be had using strips of plywood in such a configuration. See the inspiration/original at https://youtu.be/1frUIQcIg8U

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    TheCuttingBoredcharlessenf-gm

    Reply 2 months ago

    I'm confused as to why this is considered an unfaithful copy when the title of the video is "lignum inspired"?

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    TheCuttingBoredbruster999

    Reply 2 months ago

    Thanks! If you cut strips thin enough, they have enough flex to them to bend like that. Didn't wet it down at all. Instead I just did a test strip at the width I thought would work before doing all 120 of them and it was very clear from the beginning they had plenty of flex. In fact, the design could have work with a much more extreme bend.

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    Artuino

    2 months ago

    nice design..is it durable enough to withstand various body weights.there seems no support in the middle.

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    Thommyboy

    2 months ago

    Awesome job looks great and way to go thinking outside the box. When I saw your glue up of all of the strips I thought that’s going to be fun lol. And always set that bar higher it improves our skills.

    1 reply
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    TheCuttingBoredThommyboy

    Reply 2 months ago

    Oh yea - that glue up had me nervous! Using the slow cure stuff was super helpful. I planned the project with that glue in mind - otherwise I wouldn't really have known how to do it other than clamping them in groups of 3-4 I'd say. The guy who inspired this project (Lignum - on YT) does lots of bent lamination for beams and uses epoxy glue which I don't have access too, so yea, just finding a new way to push my skills!

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    Pahoolo1

    3 months ago on Step 10

    That is a genuinely
    cool way to use Plywood! I'm thinking I may do one like this, maybe a straight
    bench, (at first) with 3" wide strips for strength, (I’m kind of heavy).But I really like the look, good job!

    1 reply
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    TheCuttingBoredPahoolo1

    Reply 3 months ago

    Thanks - it is not sturdy as build (had no idea how it would come out). I can sit on it - about 160 pounds - but not hard. Would definitely solve your issue by making the strips much wider as you suggest.

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    Danger Draper

    3 months ago

    At least give the nod to Lignum for the design and inspiration
    https://youtu.be/1frUIQcIg8U

    1 reply