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I'm working on a new SJ cutaway with arm bevel. I've never done any finishing on the inside before. I noticed that Robbie O'Brien finishes his neck and end blocks with shellac. I was wondering if Howard's Feed and Wax would work well for finishing these parts... Then, I wondered about doing the kerf lining... and then what about the interior back and sides too? I think bracing should be excluded. So, what do think? Finish or not? ...Everything (except braces) or just the neck and end block? ...or forget the whole thing?

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

What I remember from posts by repair folks here on the OLF:

1. Finishing the inside makes it harder to do repairs later in the guitar’s life.

2. Finishing the inside does not protect the guitar from RH swings as much as you might think.

So, if I remember correctly, the repair folks think that it is not worth doing.

I have not finished the inside of any guitars, but based on the above reports (which I trust), I am not tempted to, either.

Steve is trying to troll Hesh into coming out of retirement.

I have considered making the neck block pretty when a side sound port is used. Something like Howard's on there might be a good and easy compromise to getting a finished look.

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I noticed that Hesh commented on a previous post. ...Nobody said anything. Don't want to scare him off.

I've never finished the inside before, but after I saw that Robbie finishes his neck block I started thinking about it. I thought rather than shellac, Howard's F & W might be an easy thing that wouldn't cause negative impacts but look nice. I am planning a soundport, which opens the insides to full inspection.

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

For me it is all natural inside the box. I would worry about the wax getting into the wood or under a loose brace and then causing adhesion problems for future repairs. At least shellac and other films wouldn't seep in as much and would be easier to abrade away.

Kent

Howard's feed and wax is something you have to use periodically to clean and brighten a finish. It's not really much of a finish by itself.
Shellac or truoil or even ragged on Poly might be a better choice.

I think you need to ask your self why. Why do you want to finish the inside of the guitar?

I have lightly sprayed urethane on the inside of several instruments to slow down the absorption of moisture during RF swings. It doesn't stop absorption but it does slow it down. You have to keep in mind that moisture will pass through most thin finishes but some are better than others at slowing it down and keeping it out. I use a very light coat.

Generally speaking oil based is the best. I have seen no negative effects from using it, but it is not for most.

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Joe Beaver
Maker of Sawdust

I have applied a light coat of shellac on the inside of the back/sides of the last two instruments that I have made. It certainly makes it look nicer - especially when there is a sound port showing off the innards of the guitar. I don't believe it is doing any good as a moisture barrier - it is purely for appearance. I didn't apply finish to the under surface of the soundboard (because it is not so visible). I understand the reasoning that it might be a problem for adherence of glues to these surfaces at a future time (e.g. cleats for crack repair).

A wax or non-drying oil product - which is what Howard's Feed & Wax is (mineral oil, naphtha, wax, orange oil) - is a terrible choice for interior finishing where future repair-ability is considered. Besides the lack of any real protection in terms of vapor transfer resistance, removing non-drying oils and wax is a challenge, and both the oils and waxes interfere with adhesives and most finishes.

Overall, interior finishing complicates repair work which requires cleats, grafts, or other additions, but shellac can be removed with less effort than wax or oil finishes or treatments.

My purely personal preference on interior appearance is unfinished, perfect joined, crisply worked surfaces planed, scraped or sanded to a buttery smoothness...it reminds me of the interiors of Japanese temples. A well-done interior speaks to me, saying "I am what I appear to be - wood and glue, harnessed to the builder's intent."

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For the times they are a changin'

- Bob Dylan

Okay... Howard's appears to be a bad idea. Sounds like the consensus is that finishing the interior (or parts of the interior) is a bad idea, which the possible exception of what Robbie does, that is using shellac on the neck block...

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

Even for just the 3 exposed sides of a neck block? I haven't done this yet (putting anything on the inside) but I have thought about it when there is a side port. I would think it wouldn't matter what you put on a neck block in terms of repair. I don't think I would do anything near braces.

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Four hundred years of tradition says use nothing...

My Kohno 30, which is a top line classical, has inside finish on the back, and probably sides, but apparently not the top. Just fyi. However, I think most top line classicals are not finished inside.

A couple of years ago, John Monteloene was at the Woodstock show and he brought his Four Seasons (?) guitars. They were not only finished on the inside, but inlaid (inlain?) on the inside, visible through the sound ports. One of them had diamonds inside. Here's one now:

https://www.metmuseum.org/art/collection/search/506137

So if a guy whose guitars can bring a million can do it - you can too.

Nothing like a little anecdotal evidence...with diamonds too!
How many times has Stradivarius rolled in his grave now?
Bottom line is "Do whatever you want."

Clearly there is room for both the natural look and some creative cosmetics...I know which I prefer, but let your tastes guide you....

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For the times they are a changin'

- Bob Dylan

I'm convinced!

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

There has always been a place for "guitars as art". It may be in a museum and not the music hall. Some ornamentation, tastefully done, is not a distraction. As with cosmetics there are some who can carry it off and others who make it look garish.

I shellac the Spanish foot in my guitars, but only because of all the end grain. Well, that and it looks pretty good. I did notice once when I was visiting Dream Guitars that many of the Somogyi x-students finish the insides of theirs. Personally I didn't like the look. Looked a little gloppy, like they were covering something up.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Waddy's post reminded me of the Greenfield video (https://www.youtube.com/watch?v=sAeXskZHC2o&t=844s), where a top is seen before gluing.
Looks as if it's finished (shellacked?) except for where it attaches to the ribs.
He did imply in an interview that he was greatly influenced by Ervin Somogyi.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.