Why do two identical guitars sound so different?

[jrfrond]

As a drummer and tech writer thereof (I do a bi-monthly Shop Talk column in Modern Drummer Magazine, where I crunch the numbers on this type of minutia), I can tell you that clear and coated ("painted") drum heads have a definite difference in response, with the coated being a bit mellower with faster decay vs. the untreated clear heads. The use of the "donut" or ring further dampens high frequencies and creates a non-linear decay, similar to stuffing foam rubber under bass strings at the bridge (like the old days) to make it "thump" more and ring less.

I can tell you that, in many instances, the finish on a guitar, even a solidbody, CAN make a difference. Case in point: A couple of years ago, I built a Tele for myself. I found an unused 1pc. swamp ash body with nice weight specs VERY cheap, because the original owner painted it. When I got the body, I realized WHY it was so cheap. A piss-poor red metallic Testors paint job. MODEL PAINTS!!! This stuff stays soft for awhile, because it has plasticizers and retarder for good flowout, so that even kids can get a nice, shiny paint job. The stuff smells too, as a result. When I finished the guitar, it sounded good, not great. After about a year, the paint fully cured and dried, sank into the grain (no grain filler was used), stopped smelling, and the guitar tone REALLY opened up. Nothing else was different or changed. Now, it's our house favorite (my son has long since adopted it). It's still kind of ugly, but it sounds so good that I won't touch it.

[Handsome Devil]

What about the pickup heights? Are they the same?

[jmaf]

...
Thick poly finishes are usually ugly. But it's like spray painting a cymbal or a drum head. It's not enough mass to really alter the tone.

The other stuff about the wood breathing, or nitro letting the moisture out of the wood is also nonsense, since wood doesn't breathe, and if a finish can let moisture out, it will let it back in too.

I've already listened to instruments I made with and without finish. I also have a few that I stripped the finish off and then oiled. It sounded the same in each instance.

Too thick a finish is not good, but there's no evidence that it will affect the tone on a solid body guitar. An acoustic guitar, yes.

Look at old Fenders and even Rickenbackers. They had a thick coat of Fullerplast, with is a catalyzed plastic like finish. Then they would spray lacquer color coats over it. They sound fine.

But I guess someone at some point figured old guitars sound better and the new ones have poly finishes, so it must be the finish.

But some very nice instruments are finished with polyester and sound good.

David, I've snipped some of your other points just to concentrate on my questions here, so it's taken out of context on purpose.

A few questions: wood doesn't breathe? How come guitar arms will bend somewhat and require adjustment when moved to more humid places on tour?

Just a few weeks ago I was chatting with luthier friends who'd tell me about the sound of finish on electric guitar. My father builds acoustics and swears by his self made rag applied varnish. Says the difference is amazing, that is as you said accoustics of course, wouldn't it have an effect on electric as well?

About applying it to drum plates, it would seem to me(completely out of intuition here, dunno whack about it technically) there are more things to it than just the mass. How the varnish would dampen the superficial vibration, etc, see if you set a bunch of cotton on top of a plate it'd sound different, having very little mass, no?

All honest questions, because the emphasis on varnish on electric guitar is so immense, if it's all BS then I think it should be officially mythbusted because folks will pay thousands more for fine varnish.