I've been reading about using tung oil inside drum shells to help keep the wood from drying out and moisture to get into the wood. The obvious concern is how does the oil affect the tonality and pitch of the drum. Does anyone has any knowledge about this and willing to share it?
I'd be very very tempted to leave well alone & instead be extra careful about how they are stored.
I've never tried it [nor would I] but tung oil works by curing to a hard, impenetrable surface.
That to me implies it will totally change the resonance of the shells.
I get the feeling [with no substantiating evidence to back me up] that if the manufacturers wanted that extra hardness/waterproofing & all the changed resonances that would imply, that they'd have made them that way to start with & tuned the shell construction to match.
Ref - Wikipedia: Tung Oil
Drums are different from woodwinds (no kidding, smartypants :-) ), so my experience may not transfer well, but: clarinet/oboe/bassoon players generally apply a small amount of bore oil to keep the wood from drying out. As with any machine, avoid over-oiling, wipe down the surfaces, etc.
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