Finishing the inside of acoustic guitars

[Grant Harding]

You almost never see it, but I've often wondered if a couple of thin coats of shellac would make a guitar less susceptible to humidity fluctuations.

 

Acoustics here seem to belly much more quickly than in Canada, but I've never seen a crack due to dryness.

 

As an aside, do you think that finished internal surfaces would make a difference to the way it sounds due to the difference in sound absorption? I don't think the finish would change the wood vibration - just the internal reflection of treble bouncing around inside.

 

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[Freeman Keller]

I've heard both arguments - a few people put a coat or two of shellac on the inside but I've never heard why they do it. Don't know if it was to help with humidity or just being anal.

 

I've also heard people argue that finishing the inside would change the sound. Again, don't know if for the better or worse or how you would even know.

[DeepEnd]

I've heard both arguments - a few people put a coat or two of shellac on the inside but I've never heard why they do it. Don't know if it was to help with humidity or just being anal.

 

I've also heard people argue that finishing the inside would change the sound. Again, don't know if for the better or worse or how you would even know.

Presumably you'd need two otherwise identical guitars, one finished on the inside and the other unfinished. What would be involved in finishing the inside of a guitar after it was built? Any pronounced difficulties? And you'd have to compare them under controlled conditions, using careful measurements.

[Grant Harding]

That was the bonus question. I'm not expecting a major change in the sound.

 

It seems logical that once you get the wood to an ideal humidity you should "lock it in" rather than leaving it to adjust to the surroundings.

 

 

[Danocoustic]

Hell, I dunno

 

I'll leave it up to Freeman to make this decision on my OM. He knows more about it than I do.

 

HOWEVER...comma... I expect my pen-and-ink nudies on the interior of this guitar! Y'all saw the thread on this topic. What I requested is well-documented. Right now we're at the point where the top is attached but the back is open. I expect some boobs. I'm old but I'm not dead.

 

Okay---i'm kidding.

 

I just want to live long enough to enjoy this thing. If I'm granted that, I'll chalk it up in the "win" column.