French Polish vs Nitro Finish

[Pura Vida]

I recently purchased an Eastman E10SS/v, which is a slope dread with Mahogany b/s and Adirondack (Red) Spruce top. This guitar is part of their Antique Varnish series, which uses a french polish, instead of the standard nitro finish. As a result, the guitar's feel and sound is responsive and airy, despite being brand new.

My other Adi tops take a year to open up and longer for the tone to sweeten, but this guitar already has a vintage tone. Since this is my first guitar with a french polish finish, I'm curious how this guitar will change over time vs. the same guitar in a nitro finish.

Edit: links to my NGD thread and Eastman's Antique Varnish process here.
https://www.acousticguitarforum.com/...d.php?t=525763
https://www.eastmanguitars.com/antique_varnish

[Steve DeRosa]

I have a ca. 1875 Bay State Style Z "peanut" parlor (equivalent to Martin Size 3), Adi/BRW/French polish, that I've owned since 1975; the tonal balance and sheer volume are surprising for such a tiny nylon-string guitar (looking to bring it back to full 19th-century specs with a set of gut strings BTW), and if this is what your Eastman holds in store there's quite a bright future ahead - here's hoping you're around in 140 years to enjoy it...

[Pura Vida]

Thanks, Steve. I'm hoping to understand some expectations in the shorter-term.

Perhaps at a more general level, I'm curious how the wood's tone and responsiveness may evolve differently on a french polish guitar vs. nitro finish. I mention Adirondack (Red) Spruce b/c that's what I have and also b/c Adi can take longer for its sound and responsiveness to evolve.

[Cool555]

Just enjoy its vintage tone now and leave the future tone to the future...

Good-looking guitar that’s made to look like a Gibson! Nice vintage color too!

[Pura Vida]

Thanks, Cool555. I'm definitely enjoying the vibe and not dwelling on it. But it's just got me thinking about how the sound and responsiveness may be influenced over time by the finish type?

It's more of a scientific question, so perhaps some of our luthier members can weigh in.

[Steadfastly]

Godin has been using that French polish finish on a number of its archtops. I think it looks best on their burst finishes.

[Bluemonk]

Originally Posted by Steadfastly

Godin has been using that French polish finish on a number of its archtops. I think it looks best on their burst finishes.

Are you sure of that? French polish is a very painstaking hands-on process and is typically reserved for quite high end instruments.

[Rosewood99]

I have two guitars built by steve Denvir that are french polish. Not sure if i can attribute the tone to that.

[Wade Hampton]

I own two guitars and one mandolin with French polish finishes. Since that’s the only way I’ve heard them, I couldn’t tell you how much the finish contributes to the sound, but all three are lively, loud and very responsive. The finish definitely contributes something to the mix.


whm

[SalFromChatham]

Finish is pretty.
Finish protects.
Errr. And the thinner it is.
The more it projects.

[Wade Hampton]

The missal wrote:

Originally Posted by themissal

Finish is pretty.
Finish protects.
Errr. And the thinner it is.
The more it projects.

You’re a poet! I didn’t know New Jersey had any poets!!


Wade Hampton “Not From Jersey” Miller

[Pura Vida]

LOL, if Sal lived elsewhere, I would have expected it in Haiku form.

Thanks, guys. I understand that the thinner finish helps it project more easily. My thoughts are more about how it may change. I've noticed some dramatic changes with Adirondack (Red) Spruce tops, both in terms of sound and responsiveness, so it's gotten me thinking how a guitar's sound may evolve differently (or not!) b/c of the thinner finish.

[Alan Carruth]

The question is, assuming guitars do change over time, what's changing? Is most of the change in the finish/glue, as some think, or is it the wood? IMO it's the wood, so the type of finish used is going to be less of an issue than how much was used.

Most makers feel that finish is a necessary evil. You need to have it to protect the wood from moisture, dirt, and grease, all of which will harm the wood over time. The finish does add mass, though, and although it can add stiffness, particularly across the grain on the top, that may or may not be what you want. Of course, a really nice finish can also bring up the look of a pretty piece of wood, and we all appreciate that, but once you've got 'enough' to protect the wood and make it look nice, any more is a drag. The big advantage of FP is that it goes on thinner than any other finish that offers similar protection against moisture, dirt, and grease. It is also very easy to touch up or renew, once you know how.

That's an important point. The fact is that a couple of thousandths of an inch of any sort of finish is not really much protection. FP is not as hard as some other finishes, particularly the modern synthetics, so it wears faster. It's also less resistant to common chemicals than many other finishes: shellac is soluble in both alcohol and alkaline water solutions, which, for some folks, equals sweat. Don't be surprised if you start seeing wood through the finish in some spots on the neck or the edges. In the old days it was not uncommon for repairmen to touch up the polish on a guitar as matter of course every time it came in for some sort of adjustment. One nice thing about it is that shellac does become less soluble with age. The problem is that it takes about 75 years for it to really become impervious.

The bottom line, IMO is that most of the 'open' sound of a new FP finish has to do with the thin coating the doesn't impede the tone much. Since I feel that most of the change in tone comes from changes in the wood over time, I would not expect the finish to have much of an effect in that respect.

When making comparisons, of course, you're going to be looking at some finishes that really do hurt the sound, and can take quite some time to become less of an issue, if ever. Some of the water based finishes I tried years ago were, almost literally, a heavy wet blanket. They went on thick, and stayed relatively soft for a long time, and really 'ate' sound. Nitro goes on thicker than FP, but can be held to a fairly thin coat with care. Since it breaks down chemically fairly fast (as such things go) the tone may well develop noticeably due to finish change. UV cure polyester, which a lot of the manufacturers and some small shops use, is very hard, and should be quite stable over time, so I would not expect that to contribute much to a change in timbre. Some of the Ovations I worked on years ago, back when I did that sort of thing, had as much as .040" of epoxy on the soundboard for a finish. You're never going to wear off an appreciable amount of that, so the mass is always there, but eventually it starts to crack and that might free things up a bit.

[Aaron Smith]

Without knowing a lot about Eastman, I'm confused by their terminology. French polishing and varnish don't really go together.

French polishing is done with shellac almost by definition, because shellac remains soluble in alcohol even when dried. It's that solubility that permits the finisher to do subsequent applications that "melt" into the earlier applications and slowly build the thickness while maintaining clarity. French polished finishes are very thin, very beautiful, and very easy to damage. Fortunately they're also pretty easy to touch up.

By contrast, varnish is a resin mixed with a solvent. When it dries, it becomes insoluble. It's great for protection, but you can't do a traditional french polishing technique with it as far as I know.

Something seems amiss in marketing-land...

[Steadfastly]

Originally Posted by Bluemonk

Are you sure of that? French polish is a very painstaking hands-on process and is typically reserved for quite high end instruments.

Yes. And they are made in Quebec which is mostly French so they have French people putting on French polish.

They actually call it a Custom Polish finish but I read somewhere awhile ago that it is akin to French polish.

https://godinguitars.com/product/5th...-burst-031986/