Introduction: Bass Saxophone Composite Case
I play Bass saxophone in a street band, it's a kind of monster saxophone 1.3 m height, giving a nice low sound. It is a a very old one (dating from year 1895), and when I bought it from another musician, I got no case but a soft bag. as I wanted to protect it from shocks and I couldn't find a case where my old sax would fit, I decided to make one by myself.
The process to make it is very similar to the process for making a surf board. The manufacturing principle of the box is to create a 'male' model with foam, that is cut and sanded to the final shape of the box. The model will be afterwards covered with glass fiber and resin that will make the hard skin of the box. The foam will be carved to create the location for the instrument.
For the case you will need:
- Foam. If you use Polyurethane foam, you can use polyester resin. If you use Polystirene foam, then you will need to use epoxy resin. In my case, I used Polyurethane foam.
- Glass fabric, it can be roving or mat. I used both.
- Resin, I used Polyester
- Hinges, latches, handles
- rubber seal
- flexible foam
- synthetic fur
- neoprene adhesive
I initially posted this instructable in my blog (in French):
Step 1: Shape the Box
To save money, I bought a foam that was thinner than the final box and I cut the foam in different pieces that I assembled with resin to create a blank with enough thichness everywhere. The foam is very easy to cut with a wood hand saw.
The blank is then cut and sanded to reach the final shape with wood sand paper and wood grate.
You can already feel the box!
Step 2: Cut the Glass Fiber Layers
The glass fiber layers must be prepared in advance before the moulding process.
They are cut with scissors. You can see here two types of glass fabrics used:
- the mat has no particular orientation, and is easily deformable during lay up.
- the fabric with plies at 45° is stronger, but is still quite deformable thanks to the 45° orientation.
I also used normal 90° fabric.
A minimum of 3 layers is necessary everywhere, and some extra layers may be added in some areas to get a thicker and more resistant skin..
Step 3: Lay Up
The principle is quite simple but nevertheless creates some stress because of the curing time of the resin. I have only poor photos (quite blurry) of this step because I couldn't take time for the pictures.
The lay up process is similar than for a surf board. A small quantity of resin is prepared with the good proportion of hardener, and then the resin is poured on the dry fabric layed up on the foam. the fabric is impregnated with resin with a brush, removing bubbles that may be enclosed. When impregnated with resin, the fabric gets flexible and it is possible to deform it around the corners and the edges. Some cuts may be necessary nevertheless. Is is important to cut in different places so that there is an overlap and weak areas are avoided.
The outer surface must be as smooth as possible, because every defect will be visible or will need to be sanded.
The lay up is done in 2 steps: a first half and when dry the second one, with an overlap. This overlap allows to reinforce the edge of the box where it will be cut.
Step 4: Coat With Compound and Sand ... and Sand ... and Sand...
The advantage of this lay up process is that you do not need a mold, the drawback is that the outer shape is not so smooth...
To improve the situation I used polyester compound used for boats or car body and sanded ... and sanded .... and sanded...
I used sanding paper with water, this gives the better finish.
The more effort you put in this step, the better the result. You can decide everytime when it is good enough for you, the choice is yours...
Step 5: Cut in 2
After tracing the cutting line, the outer skin is cut all around with a grinder. When looking again to the pictures some years after, I discover I was not so protected, be careful and be more cautious than me!
When the skin is cut, the foam is cut with a hand saw and you can open the box...
Step 6: Carve the Location of the Sax
I positionned the sax on the half box, it fits! I then traced the contour and progressively carved the location of the sax. As you see I tried to make the box as compact as possible, the sax is already 1.3 m long and when you need to find a car trunk to fit it, every cm counts!
The foam is soft and can be carved with a knife, a file, and sanding paper.
Step 7: Equip With Hinges, Hooks, Handles and Retaining Strap
The metallic parts are simply bolted through the skin, with a large washer to distribute the load. In the area of the bolt, the foam is removed.
I installed the handles between the 2 sides of the box, because a common cause for sax accidents is forgetting to close the box, lifting the box with the handle, then the box opens and the sax falls. Attaching the handle through the 2 sides makes this situation impossible because even if not fully closed, the 2 sides remain maintained by the handle.
Step 8: Finalize the Cocoon for the Beast.
For the painting process, sorry no pictures, because it was done by a friend of my son which was used to paint with a spray gun parts for motorbikes. The result is perfect.
Then I equipped the inside of the box in contact with the sax with a thin flexible foam I collected from used seat cushions.
I glued with neoprene adhesive a U shape rubber seal all along the edge of the box to have a better finish and get some kind of tightness.
I also mounted the latches. These latches allow to center the top with respect to the bottom and to close tightly.
I also glued synthetic fur inside to make a comfortable cocoon for the beast.
The box is finished and can receive the bass sax. For the mouthpiece, the neck and the harness, I made a small fabric bag which goes inside the sax bell.
Step 9: ...16 Years After
I made this box in 2003, now more than 16 years after, it is still alive and making the job.
It travelled by feet, car, bus, boat, plane and always protected perfectly the Bass sax. there is also a lot of room for stickers of bands we met.
It is not so heavy: 7.5 kg, plus the beast same weight, the total is 15 kg, it is ok when you go to the gig, not so when you come back...
I tried to install wheels but it was a total failure, it was not stable at all, I removed them. Then I put straps to put it on the back, and this works very well, although the straps where not robust enough.
The handles are ok, but it is nevertheless a long case to carry, in particular the stairs are a pain..., and I often bump doors or stairs with the front. You can see some traces with paint removed, but nothing broke, it is very robust.
And it has a little brother for my Baritone sax...
I hope you enjoyed the story, with this entry I intend to participate to the instrument contest, for sure it is not an instrument, but for me it is a very important complement to my instrument. If you liked it, please vote!
Runner Up in the