I must say, there's some great thinking going on in these posts, & almost every point made is correct
Great question. I've heard that the difference in aged wood vs newer wood is that the internal lignins (whatever they are) get hardened, transferring vibrations better.
One would think that by making the shell unbreatheable that it would inhibit the process, but I don't really know that to be true.
All true Larry, & the very reason why many 40+ year old shells sound good, despite their often patchy construction quality.
Interesting topic. I'd like to add a question if I may. Drums shells that are lacquered inside and out have essentially sealed up the wood. Will this prohibit the maturing process of the wood?
Yes it will, but it won't prevent it. Basic drying out (reduction in moisture level) is somewhat different to the drying & eventual crystallisation of lignins.
I have found that most lacquered shells although they look to be natural on the inside do have a thin coat of some kind of clear sealer. A cabinet maker told one time that if one side of the wood is to be painted, varnished, etc you must put something on the other side so the expansion, contraction rates as well as the increase and reduction of moisture due to humidity or lack of will be somewhat equal to keep the wood from warping, twisting and or splitting.
This would be true of thick sections of unprocessed wood (depending on species), but wouldn't really apply to modern ply shells. They're usually so thin compared to the older stuff, & also typically more processed (compressed, heated, etc), that they're inherently very stable, especially when the plies are very thin, as the surface area of the glue bond is huge. Ply shells get their strength by not allowing surfaces to slide in relation to each other. The strength of the whole will always overcome the tendency of an outer or inner ply to move due to normal levels of humidity deviation.
My logic tells me that lacquering or poly-ing the insides of your naked drum would make a smoother, harder, more reflective surface, resulting in a brighter sounding drum than before. I would think. If you are merely looking for protection, a linseed oil or a tung oil may do the trick, probably without changing the tone. I would think. These are all guesses because I never tried it. The oil would probably have to be reapplied every so often. I would think.
This is absolutely 100% accurate, & great advice on the tung oil / teak oil.
I would venture to say that, although an interior finish might change the sound of the drum, it's gonna be basically so insignificant (unless you do something severe, like fiberglass the interior of the shell) that you're really not going to tell. Not by human ear.
True to some extent Harry, but there are caveats. Sure, applying wax or oils to the shell will make almost no difference to the sound. Taking a thin shelled drum, & applying a good few coats of lacquer, will produce a difference in sound that anyone would be able to hear without question. Heavy lacquering does two things. 1/ it adds mass, especially noticeable on a thin shell, but this is the lesser of the two affects. 2/ It typically hardens & smooths the surface, & this can profoundly affect the timbre of the drum.
Two extreme examples would be; taking a thin softwood shell with poor finish, & applying 4/5 coats of lacquer = big difference. Taking a thicker shell made of a very hard wood that's already smooth finished inside, then adding a couple of layers of lacquer, will make almost no difference.
Years ago I sanded down the clear int of my 3 ply Luds,and applied two coats of polyurethane
satin sealer.
Big damn difference,the int was smooth and glassy and the sound was bright and it seems like tones or partials were at odds,think the sound of a basketball bouncing in an empty gym.
Exactly what I would expect, & fit's with my explanation to Harry. What may surprise you however, is that applying stuff to the
outside of certain shells, can make a noticeable difference too, but instead of surface finish being the biggest determining factor, it's mass that becomes the dominant variable. Again, only applies to thin shells, & even then, more so with higher quality shells.