The original PDF may or may not be easily available on Ocana's website. You can look for it at: http://caseyconnor.org/cajon -- if he has given permission, it will be there as well.

If you have the time to do a complete translation of the original PDF, or have any corrections, please do get in touch.

The methods we will study and that you will use are two of the most known and used by some of the most prestigious companies. It is possible that some of them may have patents, irregardless, these methods have been used for many centuries in other roles and activities, but in the modern world the person who registers a product is triumphant, not the one that creates it. So, to lessen problems we will recall that we are only providing information that will help understand the mechanism of these methods so that owner will know how to make the most of the product and solve problems with adjustment and repair. Nothing that you learn here can be used to repair a rented cajon without additional information:

The top does not need to be glued to the box, it should be screwed.

This is a very important factor when we subject ourselves to all of the various cajones available in a store. The sharp, bright sound of the strings deteriorates easily and you will need to take off the top frequently in the future. As a buyer, there is another important factor to consider. Like we have seen in the previous pictures, the cajon is nothing more than a closed box with one of its parts (the top, the thinnest) most move after being hit by all of the air in the cajon. The elegance of the resulting sound depends on how the parts of the cajon react to the hit. The moving air hits the internal faces of the cajon in waves, which should return to their place of origin with minimal degradation. The sound should not be absorbed by the material. This results in a sustainable tone with a agreeable equal oscillations. A cajon of high quality is made with a highly springy material, that, in the case of plywood and laminates, is of many layers. Try to find these cajones of many layered wood, observing the corners of the cajon is a good exercise, you will learn which ones lose less sound during the execution of a hit. Don't forget to also check the composition of the top of the cajon; although it is thin it should be like a paper of tenacity that is able to vibrate with force and response.

Page 4

Ok, now, if you have made the mistake of acquiring a cajon that doesn't not respond well, can you make it better by solving these short comings? The answer is yes. However, not with miracle results, VARNISHING THE INSIDE OF A CAJON HELPS THE AIR RETURN OFF THE WALLS, and with better results you can impregnate the inside of the box with white glue (Elmers) that is lightly diluted in water. This will harden the material making it less penetrable. This also applies to the top. The sound wave that comes from the top is like a tidal wave and with bounce off the corners of the box. You need to check all of the corners and make sure they are a tight fit.

Page 5

Where you play the cajon is important. Bricks and hard wood walls are the best for reflecting the sound back. Pine walls and plaster are not good.

Page 6

[I am going to translate the meaning from here out and not verbatim.]

Through the past various strings have been used, but acoustical an electric guitar strings work best. Then he just describes the strings of stringed instruments and how they are made. Nothing important.

[Ok, below the picture.] You can find strings with a flat core to them, but this is not important. The best strings are 0.36 or 0.38. Also, you don't have to know what note the strings would play in the guitar, but with the above numbers the shopkeeper should be able to provide you with the strings. Now we are going to learn the first method.

Page 7

We are going to locate 4 strings parallel to the roof of our cajon, the top part, the part we would hit on the cajon to get the higher tones. We will do this work in a box with out reinforcements on its corners. We will need 2 small blocks of wood about 6 x 2 x 2 cm, glue (with strong glue) the blocks the high interior wall of the cajon, like the following drawing shows. Below the picture: In these blocks we have already made the holes, 4 each, that will be used to thread the strings. Because the strings pass in front of the blocks, we do not located the blocks flush with the front corner, but we leave a small space that is equal to the thickness of the strings that we will be using. If we don't do this, when we put the top on the strings will be deformed and their performance with be hindered.

Page 8

Note: It is common to find, even in famous brands of cajones, thread blocks made from strips of pine like you find in do it your self kits. Not only is this a wood that can't be drilled because it cracks, but it also changes due to the climate, heat and humidity. Sometimes warping part of the cajon where it is mounted. To find blocks that are more resilient and stable you can take advantage of the scraps of plywood left over from the cajon construction. Glue 2 pieces of 12 mm plywood together to get a 24 mm thick piece.

Picture shows blocks with string thickness gap.

Now we will prepare the screws that pass from outside the box to inside the box that will be used to tension the strings. One screw per string. The hole that we make in the box should be 1 mm smaller that the diameter of the screw so that it digs into the wood the first time we screw it in. Also we make a hole in the tip of the screw for the string to pass through. First with a small drill bit to go through, then with a larger one to open up the entrance and exit. As shown in the picture on page 9.

Page 10

Note: the wood of the box by itself will not be strong enough to hold the string tensioner in place. as the picture shows, reinforce the side of the box with another piece of plywood, or something harder if available. Use the same high strength glue what was used on the blocks.

Another note: Also, it is common to use staplers in the construction to facilitate and expedite build time. Most of the glues used currently in the construction of flamenco cajons are water based, like white carpentry glue. The glue stays viscous when it has water in it and when it dries the water leaves. By pressing the joints with clamps while the glue is drying, excess water is pressed out and a stronger, more solid joint will be. The staple is not recommended for pieces that must withstand tension.

Page 11

Now we can thread the strings. With this method one string can be used for two lengths of our cajon, you just have to tie a knot in one end of the string so that it does not pull through the hole in the block. Do not tension the strings too much before the top in is located because the cajon will be deformed.

Page 12

Our cajon is now ready to have the top put on. Tighten well the screws that secure it. We make our first test! You should go ahead and swallow in case the result is not what you were expecting. It never is. Plywood is not a perfect material, and although at a quick look it seems flat, it can suffer alterations that deform it. This can result in the strings no touching the inside face of the cajon. We can use a piece of adhesive tape or paper that will make the strings lay against the inside face of the top of the cajon. Of course, you will have to check and see if some of the strings are not tensioned now that the top is in place. They don't need much tension, just enough so that they are drawn into a straight line.

Page 14

Playing the cajon will result in the sound changing. Also, aging will effect the sound. Air conditioned locations will dry it out, etc. If it is too damp, as the case may be in the north west, you can use an iron to dry out and "season" the cajon.