Gourd Sound Boards
Kalimba
Most people setting out to make a kalimba from a gourd would cut the gourd and glue on a wooden sound board as in this example:
I don't know why,
because this one of mine was
easier to make and sounds just as good:
Since the gourd face is not flat, I've set the bridge up on feet. This is similar, in principle, to a violin.I've used nuts and bolts to get a good tight fit, since the bridge must transmit all its vibration to the face.
For the one above, I cut the bottom of the bridge to match the gentle curve on the face of the gourd.
Mandolin
The gourd face of this mandolin is its sounding board. I don't hear any difference in the quality of sound between this one and a wooden one.
I cut slits to make the face vibrate more readily. The longer the slits, the freer the face is to vibrate, and the less it can stand up to the tension of the strings. If I wanted an 8-string mandolin, I would cut the slits last. With all the strings tuned to pitch, I would cut short slits and gradually lengthen them, watching how much the face sags and listening to how it sounds until I had a good balance between flexibility and strength.
The hardest thing about making instruments this way is cleaning the inside of the gourd through the holes. (You could cut the gourd, clean it, and glue it back together, but I prefer to clean it through the holes. That way it does not lose strength.) I used a knitting needle, dentist's tooth-cleaning tool, and wire brushes.
I made this instrument in two days, which is much less than if I'd put a wooden face on it.
Gourds make great stringed instruments, with the only drawback being that size (and therefore volume) is limited by the size of available gourds.
Appalachian Dulcimer
As with the mandolin, I cut slits to make the face of this dulcimer vibrate more readily, then positioned the bridge between the slits. The bridge has feet like a violin's, and the pressure of the strings ensures that vibration is transmitted to the sounding board.
Fiddle
Friends grew this fiddle between boards to turn its round nature into something more fiddlish. For details on how to do this, see Growing Fiddles.
Who'd have thought the shape of a canteen gourd would make a great-sounding fiddle?
