Building a Cajon (ca-hon)

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Below I’ve documented how I’m thinking about the design for my upcoming cajon project. I have a few unresolved design / construction questions that I’ll put here. I’d love any thoughts people have :slightly_smiling_face:

  1. What wood species to use
  2. How to best attach the back
  3. Ideas for the veneered front

I’m also imagining I’ll want to use tools I’m not yet inducted on, so if anybody is interested in collaborating on this or even building your own at the same time, give me a shout.

The Cajon Project

I’ve decided to build a cajón. From Google: ‘A cajón is a box-shaped percussion instrument originally from Peru, played by slapping the front or rear faces with the hands, fingers, or sometimes implements such as brushes, mallets, or sticks’. Basically it’s a box that you sit on and sounds a bit like a drum kit with a bass note and a snare. I used to play the drums and think it’ll be fun to have one and it’s relatively small so won’t clutter the flat too much.

Three cajons: Left, Thomann TCA 414, £80; middle, Meinl Artisan Solea, £233; Right, Meinl Artisan Martinete, £1066

It’s a pretty basic instrument. You’ve got a box sitting on rubber feet. A back panel with a sound hole in it. A thin plywood skin on the front called the tapa that is screwed on (to allow access inside, replacement if it breaks and for the desired sound). Inside the tapa you have either some guitar strings or a drum snare to give a snare sound.

You can buy a basic cajon for less than it’s going to cost to build it, but you can also spend >£1000 on one. A basic cajon tends to be made of plywood with extremely basic joinery (butt joints and an internal frame). They’ll have a fixed, non-adjustable snare. They seem to be totally adequate!

Mid range gets you higher quality plywood, some snare adjustment, a slightly stronger construction e.g. rabbet joints and probably some aesthetic touches like a veneered front and perhaps some other embellishments.

At the top of the range you seem to get solid wood, often poplar for some reason I haven’t yet understood, extra fancy veneers and embellishments. The construction remains pretty simple, perhaps a locking miter cut with a router for the corners. The tapa is normally still ply even at the high end for sufficient strength at 3-4mm thick, but the veneers and inlays get more exotic and pretty.

What I want to build

  • Solid wood cajon. Tbc on species. Any inputs here?
    • Poplar is tempting as it’s used on many high end cajons and is cheap. Difficulty is finding nice looking boards, I think you’d want to pick them out not order online.
    • Maple, Ash, Oak, Beech and various others are also talked about.
    • A single board will be tricky as it needs to be about 30cm wide so I was thinking of getting a thick enough board to resaw and bookmatch which should also look nice.
  • Adjustable snare. Haven’t decided whether to go for a drum snare or guitar strings yet.
  • Overbuilt joinery! I’m doing this for the woodworking project more than the instrument so I’d like to go all out. My current thinking is:
    • Mitered dovetails on the top of the case. I’ve seen examples of this being done and rounded over and it looks great! Lets hope I can be precise enough. I imagine rounding over all this changeable grain isn’t super straightforward. Would you use a router or sand the profile?

  • Half lap dovetails on the bottom, the traditional approach to the bottom of casework. The tails are on the bottom, so from the side you can’t see the joinery. If I fluff up the dovetails on the top, I could always bail on the half-laps, flip it over and have another go for the top.

  • Solid back joined somehow. I’m not sure how to do this yet. Initially I was thinking you’d bottom it out and glue it into a groove in the sides/top which would make it very strong and resistant to racking but it wouldn’t allow for wood movement. You could do this with ply, but I want a solid back. I’m now thinking you treat it like a frame and panel so recess it into a groove but with a small gap and either only glue one side, the middle or nothing at all. The challenge here would be to allow some wood movement but prevent any unwanted rattling. Any inputs here?

  • A veneered front. I’ve crossed the first hurdle finding a supplier of very high quality 3mm ply. However, I’ve never veneered anything so I don’t know how far to take this. This could be a full on marquetry project or a case of slapping on a single nice veneer. I’d love any thoughts from anybody who’s done a bit of veneering.

I’m a bit rusty with my dovetailing, so I think my plan is to keep refining the plan and sourcing materials, and in the meantime practice the mitred dovetails that I’ve never done before. I’d love any input on the project, I know we have a few folks who are into their joinery as well as some instrument makers.

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There are a few large blocks of tulipwood under the sharpening table in arch 2 that I think would be big enough.

Would you use a router or sand the profile? - I’d try router then sand, taking many small passes and with a quality bit

@mbg those are for lathe inductions, noone touch these!

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Router then sand sounds like a good plan. Perhaps with some sacrificial blocks clamped onto the ends also.

I’ll buy what I need for it, don’t want to accidentally pinch something that shouldn’t be pinched! I’d like to get it out of a single length anyway so that you get continuous grain around the case.

I made two cajons when I joned slms. One was big enugh to sit on and a handheld one. The big one is still at my storage as it got a bit damp when i left it outside (for moths by accident) and the small one is cute, but extremely impractical. I used plywood for the big one with 9mm thick walls and front and back if I remember correctly was a 2mm laseply, the bass hole I lasercut in shappes of a water ripple which i also engraved on the rest. I got a snare that i never fitted.

The small one was from a 3mm plywood and a veneer stretched over the front.

Would be nice seeing what you make, mine was more of a woodworking learning project that ended up good enough, but i am sure the tappa could be done more precisely.

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I decided I will refurbish the big cahon, thanks for inspiring me to getting it from storage @msparker

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Ah the other sharpening station - the one with the sink not the one with the tormek

Please forgive me for not recognizing that. Soz!

Np, forgot we have two now!

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It’ll go back after the scheduled woodturning inductions are over…

This looks great! Love the laser cut sound hole, that’s so unique! Where did you get the idea?

I’m largely doing it as a learning project too but with the main thing being the joinery side. I’m hoping what I learn here I can apply to things like bedside tables in the future. I’ve also never veneered anything so that could be cool. I saw a video yesterday about laser cut marquetry which was thought provoking! I do also wonder about using veneers to make up ply from scratch as I hear the tapa wood can make quite a difference but perhaps that’s better as something to retrofit down the line. Veneering onto a birch ply substrate sounds a lot easier.

Yes!!! I hear a drum circle coming :stuck_out_tongue:

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I am a creative person actually.

Makes me think I should make more, try to sell them. Will try making another one, but better.

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those look great! very creative!

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I finished this a couple of weeks ago but have been too lazy to post! Here are some photos of it in progress and finished. A big thank you to lots of people who helped along the way, especially @Ryanf who helped me with tool inductions, glue ups and lots of advice!

In the end, not much changed from my plans. I went with mitred through dovetails on the top and half blinds on the bottom, used guitar strings for the snare and tried out some veneering for the tapa(s).

I made two different tapas (the front bit), one is a four way bookmatched poplar burl (mappa) veneer, the other is a rippled mahogany. Neither are perfect, it turns out veneering is hard, so a third may happen one day but for now I’m largely happy with it. I think all the joints came out great and I’m very happy with the Kiaat wood I used which got lots of interest at the makerspace.

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Looks really good, what finish did you end up applying?

But is it a Cahon if we don’t hear it being played, or is it just a table? :slight_smile:

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Haha, maybe after some practice :smile: I think it sounds pretty decent but I don’t have a good reference point. I’d like to have a go on a commercial one and see. The snare for instance was just a guess of how to do it well and could probably be tweaked.

I went with Osmo as I had it and knew I could get a decent finish with it. I would like to try some other finishes though

Looks really great! Did you cut the joints with a hand saw?

Yep, the joinery was done by hand :slight_smile: I tried out the dovetail guide and it was excellent!

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That’s so pretty :heart_eyes_cat: