To begin experimenting one needs only a holding tank or container, a transducer (underwater speaker) and a sound generator.
Hornady and
Harbor Freight both market specialized ultrasonic cleaners. On
ebay a whole spectrum of ultrasonic equipment from tiny jewelry to large industrial sized cleaners can be found.
TANKS
The tanks or trays used in most “store bought” ultrasonic cleaners are made of stainless steel. Cavitation resistant, buffed and polished stainless steel tanks are best. Surface imperfections or scratches on the tank walls might draw or form bubbles which is undesirable (you want bubbles to form on the dirty item to be cleaned – or on your oak hypothetically). Rubber, plastic or even epoxy paint coatings on the inside of a tank are preferable and less corrode-able than simple steel surfaces. Suspect that glass and ceramic containers would preform admirably.
TRANSDUCERS
Several types including capacitive-micromachined, piezoelectric,
Plate-Electric-Ceramic-Sheet,
BLT (not Bacon, Lettuce & Tomato but “Bolt-clamped Langevin Type transducers), etc.
GENERATORS
The difference between an
ultrasound generator and a simple power board is that the generator rather than being fixed, probably offers variability in both its output frequency and its wattage. The chosen operating frequency is probably a trade-off between surface penetration and cavitation inception. Sometimes a pair or multiple frequencies might be used simultaneously. Adjustable wattage can accommodate power for a variable number of transducers. Low ultrasonic frequencies are desirable for coarse cleansing while Higher frequencies would be appropriate for fine cleaning. Cheap (
Raspberry Pi sized) circuit boards comprised of a little transformer and a few capacitors are all that is necessary to create a signal to drive through the immersible transducer. If or when a tank, a horn and an ideal frequency and wattage have been selected then the need for the costly variable generator diminishes.
A small investment in ultrasonic equipment and experimentation would not go wasted. Besides a host of cleaning applications this ultrasonic equipment could in return be put to use for mixing biodiesel, for a building a homespun seismographic ground sonar, for solids separation, for
plastic welding, to stop barnacle growth on a boat's hull, to repel birds from an orchard or rodents from a barn or to power a grandkid's experimental
traveling wave ultrasonic motor (tiny devices that since the 1980s have been used in things like the autofocus lenses of some DSLR cameras).
If I was bored and idle and had a few neglected gallons of caustic white hooch laying around, then I'd be toying with ultrasound right now.