Pirate's Treasure Chest

Treasure chests in the pirate style with the rounded lid look a little tricky to make. They're not - here's how to make one out of old wood you may have lying around, and you only need one measurement. Here it is: 10 degrees. Right, you're ready to go!

I made the chest from some left over wood from our neighbor's fence. I'd used a fair bit of it to build a treehouse, and my kids were busting to have a piratey treasure chest to store their loot in. I thought I'd try my hand, and it turned out to be easy enough to share how to make it.

Step 1: Tools

This project is technically woodworking but requires no real finesse, just as well, or I couldn't have built it! However, you will need access to a power tool that only a woodworker would own: a table saw. This is really the only way you can accurately rip lumber. However, you don't need a fancy one with a cast iron table; though if you have one of those, I envy you, as mine is a crappy little store-brand bench saw that cost $75 new. A jigsaw is handy (though a fine-toothed handsaw would work perfectly well). You'll need a hand plane, and a hammer or a nailgun. Some ratcheting tie-downs are useful, but there are lots of other ways to apply the pressure to glue this project together. Oh yes, some PVA wood glue. You'll need a pencil, but you DON'T need any measuring tools. Really. No tape measures or rulers were exploited in the execution of this project.

Step 2: Pick a Length and Rip Your Boards

But... but... you said no measurements! Well, yes, but you have to decide how long your treasure chest should be. I just picked the length that would allow me to waste as little wood as possible - I had old six-foot long cedar boards, so I cut the rot off each end and got two lengths out of each piece. The wood I used was nominally 10 x 1, but it varied wildly in width and thickness. If yours are more consistent, your job will be easier.
Rip your boards at a 10 degree angle using a table saw, as shown in the photo to give them a trapezoidal cross section. Alternate the angle, and keep the fence setting for all cuts. If you organise things well, you won't waste much wood at all.
How wide do you make each board? Well, some simple circle geometry: you will need 10 boards to bring them around in a semicircle (9 joins between 10 boards, each join 2 x 10 degrees, so 9 x 2 x 10 = 180 degrees) and leave the outside boards vertical; you can use 9 boards if you're not fussed with this final requirement. The longest edge of your trapezoid is one eighteenth of a circumference, and the circumference of a circle is related to its diameter by pi (~3.14). So the width of your treasure chest will be 18/pi (about 6) x the length of the longest edge. So, for example, if your long edge is 2", your treasure chest will be a little less than 1' wide.
To make your life easier, your treasure chest should be no more than twice as wide as your widest board. You'll see why in the next step.

Step 3: Make the Ends

You generate the pattern for the ends just by tracing the trapezoidal outline of one of your boards 10 times on another board, as shown in the picture. The more careful you are, the better it will look. Cut to the inside line using a jigsaw or handsaw (my floor looked as in the picture after this step). Use the cut end piece as template for the other end.

Step 4: Nail and Glue

Glue and nail the boards to the end pieces and each other. I used a nail gun, but hammering in finishing nails would work fine too. You'll need to punch the nails below the surface.

Step 5: Clamp

How do you clamp something as weirdly shaped as this? Easy - use some tie-downs. I used the ratcheting type, which had, if anything, too much oomph. Strap them around and tighten until the glue starts to squeeze out. You could just use rope, and tension with a trucker's hitch. Wood glue is strong and pretty forgiving.

Step 6: Plane Smooth

After leaving the tie-downs on for 20 minutes, remove and clean the glue off (or if you're smarter than me, you would have put some newspaper down first to stop the straps getting gluey in the first place). Scrape the glue off. At this stage, it might not look too promising, but a few passes with the plane makes it come up really nice. I have a little Stanley block plane; it worked beautifully for this job. I didn't take too much off because I wanted to preserve some texture, but you could make the whole lid really smooth if you liked. Sanding optional. You'll also need to plane off the edges, because they'll have a bevel on them that you don't need.

Step 7: Make the Box to Match

The box must be the same size as the lid, whatever that happens to be. The depth is also optional - I just used the width of the old cedar boards I used to make the lid. Same for the base. Again, glue and nail; I didn't use clamps, but by all means do so if you have them. Now add hinges. I had a leftover piece of piano hinge, so used that. Real piratey ones on the outside of the chest would be way cooler.

Step 8: Paint and Add Hardware

We used leftover acrylic exterior paint, which hides a multitude of sins in one coat. A stenciled skull and crossbones would seem just the ticket!

Comments

[handcraftedbycunningham]

What is the wood dimension you used? 2x4x10, 1x4x10? I'm building this for my sons birthday.

[makendo]

It was a recycled cedar fence, and the boards were nominally 1x10 (the ends were rotten, so got trimmed off). I think the wood was about 3/4” thick for the most part.

[handcraftedbycunningham]

Awesome! Thank you for sharing this!

[mcorpuz9]

how did you cut the curved board? (the half circle part?)

[makendo]

I used a jigsaw, but because they're all external cuts you could use anything - handsaw, table saw, circular saw. Whatever is quickest & easiest for you.

[ScottM456]

great job on this tutorial.

Had enough info to do it , but no much as to confuse.

I especially appreciate math. With your help, the geometry all came back. (Mom said I would need it someday. And, sob, 60 years later? Boom! Need to know It.)

I'm making one roughly 6x10 for my grand son. The 10 degree thing, perfect. I made my slats 1 inch wide. The diameter was a skosh over 6 inches. (HIGH FIVE.)

[donGrumps]

How did you come by the 10 degree angle for the top? I have been asked to do a larger project where i want to make an arched top. Just wanting to understand the angles to figure out what will work for me. Thanks don

[makendo]

You need the boards to turn a total of 180°, so at 10° per cut that makes 20° at each joint. 20 x 9 = 180.

[donGrumps]

Thank you. Makes perfect sense ... now.

[Kellasik]

love the build and it looks great. I wanna make one myself about 24inch wide and 36inch long....i suck at math and idea how wide the top boards would need to be and what angles to cut em at?

[ShadeKeeper]

This is a wonderful, simple design. The only changes I plan to make are the paint/designs, and putting some chains on the inside to prevent the lid from opening to the full extent of the hinges.

[makendo]

Thanks! Good luck with the build.

[ChrisB458]

Sweet design , i too made one after see what you did for my son as well. Like the style of chest, you have any other projects in wood work?

[Captain Teague 1978]

I love this. It has inspired me to make one myself. I might start with a smaller version before I scale up.

[makendo]

Thanks. You should, it's fun to build.

[CameronF3]

Masking tape, duct tape all work especially well on many odd shapes when glueing up. Lie the tape upside down n place pieces on it, glue edges n simply pull tape together and leave to dry

[makendo]

Agreed (also see https://www.instructables.com/id/Improvised-woodworking-clamps/ for other makeshift clamps), but in this case tape wouldn't do much - it's good for holding pieces next to each other, but not pulling them together. I guess it might be OK if you wrap it around and around enough times.

[ChancejSanford]

thanks for sharing this, I needed some thing to build in wood tec. and my little sister just "broke" her toy box so it works out

[dpaxton]

very nice! i always wondered how to build a treasure chest! now i can hide my loot :) ty

[makendo]

Arrr! Y'll protect ye booty from them scurvy lubbers an' bilge rats!
Ahem. I mean, thanks.