Introduction: Pirate's Treasure Chest

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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

Picture of 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!


Kellasik (author)2017-08-07

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?

mattF58 (author)2017-07-10

The build looks great. I love it. I am starting to make it myself. As I was getting started I noticed that the calculation is slightly incorrect.

I am super sorry about this but the math is slightly incorrect on the semi-circle.

A polygon with a 20 degree exterior angle (10 degrees on 2 boards) has 18 sides (9 for 1/2 of the polygon, or 1/2 of the circle). Therefore 1/2 of the polygon would have 9 sides, IF you are using a 10 degree chamfer.

A 20 sided polygon (10 "sides" for half a "circle") has an exterior angle of 18 degrees (9 degrees per board) AND the beginning and ending boards will not be "vertical" but that's not a big deal.

So, EITHER use 10 degree and 9 boards


10 boards and 9 degrees

sorry but the math is the math

makendo (author)mattF582017-07-12

I've clarified the instructions by saying "and leave the outside boards vertical; you can use 9 boards if you're not fussed with this final requirement". Thanks, well spotted; pro membership sent.

mattF58 made it! (author)makendo2017-07-15

Thanks again. check it out. Inspired by your idea. I'm almost finished. Here is my iteration.

no paint yet. no hardware yet. I made the front and back from tongue/groove with a nice beadboard pattern.

I tapered my box front and rear at 10 degrees. I left the sides vertical.

I added faux "framing" to the box - image 4

makendo (author)mattF582017-07-15

looks great!

increddibelly (author)2017-03-29

Thank you for finally giving me an excuse to get a table saw!

I'm thinking of adding corners to the bottomsuch as these:

I only have narrow boards (50mm / <2in) so I intend to do the lid with 20 beams at 5 degrees. This should give me a smoother curve to the lid for free.

increddibelly made it! (author)increddibelly2017-04-14

progress is goooood.
I had a math fail at some point - I only needed 18 beams instead of the 20 I calculated. I can't explain it other than my bad craftmanship and sawing at an angle greater than the intended 5 degrees :D

I'm currently working on the bottom of the chest, and when that's finished I'm going to add a nice angled frame to the case as seen in the last picture.
I also have a ton of horribly kitsch brass hinges, locks, corner brackets and actual brass furniture feet underway from china - you wouldn't believe the kitschy stuff they have on offer!

mattF58 (author)increddibelly2017-07-10

your calculations on 18 beams is correct. see my comment above. @ 5 degrees you only need 18 beams to make a semicircle

increddibelly (author)mattF582017-07-11

if only I'd realized that before I sawed 20 parts instead of 18 ;)

I reused the last 2 for the bottom though. Dude, I Had a blast! making this the kids love it. I love it. Heck, even the wife smiles at it occasionally ;)

makendo (author)increddibelly2017-04-16

progress is good, looking great so far

Well, almost finished. Loved every bit of it and I think I went a little overboard. As a pleasant surprise, there's a pirate theme at the kids' school this month, and guess what's the centerpiece :D

makendo (author)increddibelly2017-03-30

great idea. have fun with the build

Lbabiar made it! (author)2016-01-11

Thanks so much for this instructable!!! I am a novice to woodworking but really wanted to make something special for my 4 year old nephew for Christmas. Although it is not perfect, I'm very pleased with how it came out. And best of all my Nephew loves it! Really appreciate the clear instructions!!

increddibelly (author)Lbabiar2017-03-29

I like that you glued the top panels to the side instead of putting the panels on top of the side! I'm going to do it this way too. If you use thick sides, it gives a suggestion that the cover is also very thick. A nice effect!

makendo (author)Lbabiar2016-01-11

It looks fantastic, congratulations! Many thanks for posting the photos.

ShadeKeeper (author)2016-09-28

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 (author)ShadeKeeper2016-09-28

Thanks! Good luck with the build.

ChrisB458 (author)2016-05-11

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 (author)2016-01-10

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

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

CameronF3 (author)2015-11-18

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 (author)CameronF32015-11-18

Agreed (also see 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.

Admiral_Ash made it! (author)2014-04-02

Thanks for these instructions! Knocked most of one of these out in a day. I have a buddy who has a forge and this weekend we'll be making steel bands for the top. Spent a few hours blackening some bolts so they'll match the steel. I'll upload some more pics once it's all finished.

makendo (author)Admiral_Ash2014-04-02

Looks great, nice work & thanks for uploading the pictures. Steel bands sound awesome, look forward to seeing the final version.

Admiral_Ash (author)makendo2014-04-04

Couldn't wait for the weekend! Did these last night and tonight I'm going to continue the steel bands down onto the main box. My bud is going to forge some nice handles Saturday. Hinges and jailers lock should be arriving today from amazon.

ChancejSanford (author)2014-01-15

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 (author)2011-09-25

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

makendo (author)dpaxton2011-09-26

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

opticalfx (author)2011-04-25

Wax paper works better than newspaper as the glue won't stick to it

ddarkeststar (author)2011-03-06

Nice one man.

Yeah Yeah 5166 (author)2010-09-19

Looks great!! And love the commentary!!

makendo (author)Yeah Yeah 51662010-09-20

Thanks, glad you enjoyed it!

Junkyard Dawg (author)2010-09-05

I'm going to have to build one of these now. I love old looking stuff. After painting, just leave out side for a month or two, and get an instant aged look. The only problem for me is that I don't have a table saw. Hmm, I doubt I'll ever use it for anything other than this one project, so a cheep $75.00 saw may work for me. Thank you for the ideas

makendo (author)Junkyard Dawg2010-09-05

Good luck, it's a fun & easy project. Borrow a table saw if you can; lots of people own one, even if it's collecting dust in their garage...

Junkyard Dawg (author)makendo2010-09-05

Well, the only place I know of that has a table saw is with my old shop teacher from Junior High, but I think he retired (and the shop is now a computer lab) Mabe I out to try with one of my uncles. They may have one. If all else fails, I'll just buy a used one from a yard sale or a thrift store (Or, Craigs list. There are some good deals there)

Dizzy49 (author)2009-11-08

You can take the stainless steel hardware and drop it in vinegar for a 2-3 days and it will give it a very nice aged look.  I needed some authentic looking screws for a 150yr old cabinet in my kitchen and that did the trick for me.

makendo (author)Dizzy492009-11-08

 Interesting, I would have thought stainless steel would stand up pretty well to vinegar. What does it look like after the process?

Dizzy49 (author)makendo2009-11-08

I tried steel and brass, and the brass didn't do anything, but the steel turned out great!  If I can find the cable for my camera I'll put up a couple pics of the original screws and the ones I made.

fretted (author)Dizzy492010-04-20

If you want to put an old antique look on new brass soak it in lighter fluid for awhile or just use some on a rag and wipe it down and let it dry i had to antique the front of some new brass mailboxes for a very old apartment complex built in the 20's and it turned out great

Wasagi (author)2009-10-21

The one thing I've always needed!

As soon as I get some time, I'm making this!

SpinWard (author)2009-10-19

I love this, I was looking for a pirate chest last month too for my son's birthday!! I may have to make this for Christmas!
I love the idea of the ratchet straps to hold it together for the glue. That was the one part that intimitated me about a pirate chest! I may see fi I can find some brassy looking straps and tacks for the sides.

Very well done!!

makendo (author)SpinWard2009-10-19

 Thanks & good luck. If you have ratcheting tie downs, take care you don't overtighten them - I did at first and must have come pretty close to snapping the outer pieces or at least tearing them off the ends. In hindsight, the best way to do it would be to cut a piece of scrap wood to fit across the inside, then clamp really tight around that. It would stop the sides bowing in when you apply pressure.

jtp139 (author)2009-10-19

i can't believe it! i was just searching for a treasure chest like last week and there wasn't anything. Thanks for the instructable.

makendo (author)jtp1392009-10-19

 You're welcome. Good luck - I hope it works out for you. 

tim_n (author)2009-10-19

Looks great - I might make something similar but to make it a bit more authentic it really needs a bit of destressing! (smack it with a hammer and burn it a bit etc) and use old locks (rusty).  But the box looks solid!  Well done!

makendo (author)tim_n2009-10-19

 Thanks. Its authenticity is most definitely lacking - the piano hinge is particularly vile. However, the kids are saving their pocket money for a lock and I'm confident that they'll distress it quite enough through regular use (though I'll probably discourage the burning).

thepelton (author)2009-10-19

If you use brass fittings, you can let them turn green and it won't really hurt the hardware.  Rusty iron is decomposing.

About This Instructable




Bio: Analog maker dabbling in digital manufacture
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