Tuning the tubes...with wax!

Hello World,

it has been a while since there was activity here - today, I've tested an idea on how to tune the resonator tubes without glue, caps, sanding and all that other mechanical hassle.

The idea is simple: Pour some liquid into the half-closed tube to change its resonating frequency and create an airtight seal. This works exceptionally well, try it with a trekking water bottle and hum into it while adding water. But I don't want to grow flowers in the marimba, also water evaporates rather quickly...so what else is there: engine oil (probably works, but stinks), cooking oil (gets sour and stinks), epoxy raisin (one hell to work with), hmmm, sticky and sealing - yes! It will be candle WAX.

OK, here's what I did:

1. Cut the tube to the specified length (it's a lambda/4 resonator).
2. Grind the edges to be smooth.
3. Put a deep freeze satchet over one end, fix with rubber rings.
4. Melt some candle wax.
5. Pour into tube until frequency is ok.
6. Let cool and harden.
7. Gently remove deep freeze satchet.
8. Done!

The resonating frequency is best measured by tapping the whole tube gently on the floor, this excites the fundamental resonance frequency of the tube clear enough for a tuner to hear it. Tapping on the side excites a lot of other frequencies as well, which might irritate a tuner. The resulting sound of the marimba with a resonant tube is really cool!

Questions for now:

• Is the wax sticky enough to stay in place?
• When completely cooled down to room temperature, does it shrink?
• Does the heat from the molten wax disturb the tuning in a relevant way?

This is what it looks like:

 That's the tube for the middle C. It is a sewage tube.

 That is the bottom view of the tube. The wax nicely seals the tube. The indentations of the deep freeze satchet can clearly be seen, but this does not matter on the outside.

 This is the inside view of the bottom of the tube. The wide angle lens makes it look like a ball, but in fact it is a totally flat surface.

Stay tuned and in resonance! Maybe I'll do a video about the whole process, it is really fun. And of course, some proper sound samples must be done!