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Guitar Makers

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Discussion Forum

Restoring a Miniature 6 Replies

Started by Luis Motta da Silva. Last reply by Luis Motta da Silva Mar 1.

What's inside a Portuguese guitar? 1 Reply

Started by Luis Motta da Silva. Last reply by Kevin McCornack aka Dr. Moreau Aug 31, 2014.

Inlays. How to? 10 Replies

Started by Luis Motta da Silva. Last reply by Luis Motta da Silva Jan 4, 2014.

Comment Wall


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Comment by Edward Sparks on January 20, 2012 at 7:33am

A ? do you coat the inside of an acoustic guitar???  I have to assume it's before you glue on the top?  Just curious!

Comment by Jay Lichty on January 20, 2012 at 7:29am

For what it is worth I started coating the inside back and sides of my guitars and ukuleles about 10 instruments ago. I started doing this at first because, in my opinion, it should help stabilize the more (delicate) crack prone woods like Brazilian rosewood and Zircote. I was really pleased with how it looked as well as the affect I perceived to the sound and projection. I only use well-seasoned wood and keep my entire rather small shop as close to 45% humidity as I can but I did still have an issue with some BRW so wanted a little extra “insurance” against future issues. Additionally as an experiment I built a guitar out of a back and side set that really had limited tap tone to see what kind of tone I could create. As part of my strategy I did three coats of shellac on the inside of the back and sides. The resulting build was quite astonishing and the tone, projection and sustain well surpassed my expectations. It is one of my favorite guitars now. Thanks to Jud for bringing this topic up because I am also very interested in the experience and opinions of you all.


Comment by Greg Nelson on January 20, 2012 at 6:14am

This subject comes up on occasion and I don't think there is a right or wrong answer.  Tradition is to not finish the interior but many fine instruments do have at least a wash coat inside.

Finishing does change the tone but the question of "better or worse" is subjective. I don't think you can claim sonic improvement or degradation. To be honest I like the sound of instruments in the white and wold prefer no finish at all but the down sides are huge.

The argument about sealing the woods to protect them against rapid changes due to RH is a good one. A sealed finish will slow the movement of moisture in and out of the wood compared to no finish. Will it prevent a crack? Too many other variables to make an definitive answer for that.

In the end people don't like surprises.  Finishing the interior is "different" so there will be resistance to it by many. A few have embraced it. Vive la difference!

Comment by Jud Hair on January 20, 2012 at 3:38am

Here is a thread on another forum debating the question.  Seems like a couple of makers there are convinced its a good idea.  They are arguing in favor, mainly over perceived sonic improvement, disregarding (in my opinion) other important problems that could result.

Comment by Charles F Morrison on January 19, 2012 at 8:04pm

I don't finish the insides, although I know of some who do. I never felt the need and was never convinced that it would be effective anyway.

In addition, consider the poor repair guy/gal who ends up having to cleat that unfortunate crack and finds the glue won't stick to that interior finish.

Comment by Greg Brandt / Maker of Guitars on January 19, 2012 at 7:13pm

In classical guitarville.....some makers wash coat the inside w/ shellac. My teacher used to spray a coat of lacquer on the inside of the sides and back but never the top. I never finish the inside in any way. I've just never been convinced there was a good reason to do so. Some makers think it might "seal" the wood in a way and help to prevent cracks or offer some sort of stabilization for the wood. I always figure that if the top (and the guitar in total) is made in a proper environment humidity's not needed.

I'll be interested in what others say.


Comment by Dave G on January 19, 2012 at 7:09pm

Ed's right.  It's good for siding but not tonewoods. 

Comment by Edward Sparks on January 19, 2012 at 6:56pm

I have never done it or heard of doing so...I think it could inhibit the wood from "breathing" and mellowing in over time...but I am no expert...I'll be interested in what the others here have to say!  Thanks for posing the question!  Edward

Comment by Jud Hair on January 19, 2012 at 4:53pm

QUESTION: Putting any sort of sealant inside the interior of an acoustic guitar?

Yes?  No?  Maybe?

What's the opinion of you skilled guitar makers.

Comment by Greg Brandt / Maker of Guitars on December 27, 2011 at 7:00pm

It was the fumes from the stripper that made the 4th pc disappear LOL. I looked at the eBay pictures, I wasn't sure if it wasn't a 4pc top but it wasn't clear enough.

Again....nice job and good luck!


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