Is French Polish that much better aurally?

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Conall
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Is French Polish that much better aurally?

Post by Conall » Wed Sep 11, 2019 11:42 am

I have 2 good guitars: one French polished (2019) which is already wearing off in places and the other (which is a higher value guitar from 1993) has some other type of varnish which looks better / hasn't worn over the 25+ years I've had it.

The 1993 guitar has a stronger (louder) fundamental tone than the 2019 guitar.

I know the current fashion among luthiers is to use French polish rather than other types of varnish but is it really that much better aurally?

I really don't care about the appearance of the finish (though I'm not fond of the matt / vinyl / silk type of finish some cheaper guitars have) as long as it protects the guitar and doesn't adversely affect the tone of the instrument. I know that logically a thinner finish will let the top vibrate more freely than a thick varnish & therefore it should be better aurally but are there not good alternative, harder wearing varnishes that are equally or nearly as good aurally? My 1993 guitar still sounds brilliant (and mint examples are advertised at high prices).

If I can find a local luthier (Scotland) who is willing to strip off the FP on my 2019 guitar & replace it with a durable yet light alternative varnish I'd consider doing so provided I'm not likely to hear a negative difference.

Any thoughts / recommendations for alternatives to FP?

RobMacKillop
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Re: Is French Polish that much better aurally?

Post by RobMacKillop » Wed Sep 11, 2019 12:13 pm

Colin Morison near Forfar might do it for you. He's a very good luthier. As for the difference in sound - I can't help you. I do prefer light guitars with a thin soundboard, and with French polish or oil, as the thin soundboard needs to move. But with thicker soundboards (and I imagine your large 11-string should be on the thicker side) I would imagine a stronger finish. But I'm not a luthier.

Conall
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Re: Is French Polish that much better aurally?

Post by Conall » Wed Sep 11, 2019 1:40 pm

RobMacKillop wrote:
Wed Sep 11, 2019 12:13 pm
Colin Morison near Forfar might do it for you. He's a very good luthier. As for the difference in sound - I can't help you. I do prefer light guitars with a thin soundboard, and with French polish or oil, as the thin soundboard needs to move. But with thicker soundboards (and I imagine your large 11-string should be on the thicker side) I would imagine a stronger finish. But I'm not a luthier.
Hi Rob,

- I know of Colin having been at a couple talks by him & some of his recent guitars sound really good & (relevant to my post) their finish look great too. I'll either try him or the other 2 or so Scottish luthiers I know of - or all of them. I gather one of the reasons luthiers nowadays often prefer FP is because of the negative health aspects of some of the other finishes.

Thanks for the suggestion,

C.

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Cloth Ears
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Re: Is French Polish that much better aurally?

Post by Cloth Ears » Wed Sep 11, 2019 2:24 pm

Frédéric Chopin is the best of French Polish aurally. I'll get my coat..

Conall
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Re: Is French Polish that much better aurally?

Post by Conall » Wed Sep 11, 2019 3:53 pm

Cloth Ears wrote:
Wed Sep 11, 2019 2:24 pm
Frédéric Chopin is the best of French Polish aurally. I'll get my coat..
Ok, ok - don't rub it in....but I wish some of Chopin's talent would rub off on me....

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Denian Arcoleo
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Re: Is French Polish that much better aurally?

Post by Denian Arcoleo » Wed Sep 11, 2019 4:22 pm

Cloth Ears wrote:
Wed Sep 11, 2019 2:24 pm
Frédéric Chopin is the best of French Polish aurally. I'll get my coat..
:lol:

Alan Carruth
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Re: Is French Polish that much better aurally?

Post by Alan Carruth » Wed Sep 11, 2019 5:16 pm

Finish is, in many respects, a necessary evil. You have to do something to protect the wood from dirt, grease, and wear, but any finish adds mass, which we try to avoid. Finishes that contain oil also add damping, which dissipates sound more quickly, especially in the higher frequency range. Since the problem with Classical guitars is the intrinsic lack of highs in the strings due the the damping of nylon or gut, it makes sense to avoid adding any more than you need to with the finish.

Shellac and lacquer have low damping. Of the two, shellac is more stable over the long run: nitro breaks down, but shellac cross links and gets stronger and more chemical resistant. Sadly, it takes a long time for shellac to really become impervious 75 years or so. Shellac when it's new is soluble in alcohol and in alkaline water solutions, which seems to include sweat for many people.

Traditional oil-resin varnishes do have some oil in them, and thus have higher damping that shellac. 'Spar' or 'long oil' varnishes have more oil than 'short oil' or 'rubbing' varnishes. Many of the latter don't add much damping at all, so far as I've been able to find out. The oil content does contribute a lot to solvent resistance, and many of the better varnishes are quite stable over time, and remain flexible and tough.

The main thing to pay attention to is how much finish you end up with on the surface. A good French polish job will be .002" thick (.05 mm) or less. It's difficult to get a good coating of anything else at that thickness, but some oil-resin varnishes can end up at .0025"-.003". It's hard to get a spray finish such as lacquer thinner than .005", and many are much thicker than that. I've seen water based finishes that build to .008" or more. The 'prize' there is the finish I measured when I replaced the top on an Ovation guitar some years back: it was epoxy, .04" thick, a full millimeter, and hard as a rock.

The bottom line IMO is that 'less is more', so long as it provides the protection it's supposed to. In high wear spots FP makes little sense, especially in places like the neck that have very little bearing on the sound, if any. FP on the top provides the protective coating you need, and can be durable enough if you're careful. Even the slightest touch can mark it on a cedar top, though; spruce is a bit better. A slightly thicker coat of a good varnish might just be enough more durable to be a good trade-off with minimal impact on the sound.

Conall
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Re: Is French Polish that much better aurally?

Post by Conall » Wed Sep 11, 2019 5:32 pm

Alan Carruth wrote:
Wed Sep 11, 2019 5:16 pm
Finish is, in many respects, a necessary evil. You have to
The bottom line IMO is that 'less is more', so long as it provides the protection it's supposed to. In high wear spots FP makes little sense, especially in places like the neck that have very little bearing on the sound, if any. FP on the top provides the protective coating you need, and can be durable enough if you're careful. Even the slightest touch can mark it on a cedar top, though; spruce is a bit better. A slightly thicker coat of a good varnish might just be enough more durable to be a good trade-off with minimal impact on the sound.
Sounds like great advice Alan, thank you!

Could you recommend a particular varnish other than FP for the top (& thicker one for neck etc or same varnish but thicker) so I can ask a local luthier if he can / is willing to put it on my guitar?

I'd ask you ....but I think an ocean separates us!

Alan Carruth
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Re: Is French Polish that much better aurally?

Post by Alan Carruth » Wed Sep 11, 2019 6:21 pm

I'm not sure what's available outside of the US. Several luthiers have used Pratt & Lambert's #38 varnish for some time with good results. It's a 'short' oil varnish, and gets reasonably hard. I've been using Murdoch's 'Ure-Alkyd 500' varnish from Sutherland-Welles Co. recently. It can be problematic on some tropical woods, where the oils interfere with drying. It goes on thinner than most, is quite hard (which some might thing a draw back) and looks particularly nice. I have used a number of other varnishes over the years, usually going to some new brand when the one I've been using is discontinued for some reason. They all have advantages and drawbacks, and you have to learn to work with each one as it is. Keep in mind that 'varnish' is a class of materials, as 'wood' is: the name subsumes a wide range of different things.

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joachim33
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Re: Is French Polish that much better aurally?

Post by joachim33 » Wed Sep 11, 2019 7:09 pm

I am left wondering, whether you should wear the FP a bit more and get it re-polished at some point in the future. The advocates of FP claim the ease with which it could be redone as one of its strength.

I also wonder what is wrong here. In half a year the polish should still be able to offer sufficient protection of the wood. If I was still living in Scotland, I would try to get an opinion from and consult with James. Scotland to Yorkshire isn’t that far, isn’t it?

Conall
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Re: Is French Polish that much better aurally?

Post by Conall » Thu Sep 12, 2019 6:45 am

joachim33 wrote:
Wed Sep 11, 2019 7:09 pm
I am left wondering, whether you should wear the FP a bit more and get it re-polished at some point in the future. The advocates of FP claim the ease with which it could be redone as one of its strength.

I also wonder what is wrong here. In half a year the polish should still be able to offer sufficient protection of the wood. If I was still living in Scotland, I would try to get an opinion from and consult with James. Scotland to Yorkshire isn’t that far, isn’t it?
The polish has worn considerably in high contact areas (I don't think it was especially well put on initially). I could put up with it another while but it's a bit ugly.

Which James in Yorkshire? I live in Aberdeen so that's a long journey (Glasgow's bad enough but just about doable in one day).

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joachim33
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Re: Is French Polish that much better aurally?

Post by joachim33 » Thu Sep 12, 2019 7:02 am

Conall wrote:
Thu Sep 12, 2019 6:45 am
joachim33 wrote:
Wed Sep 11, 2019 7:09 pm
I am left wondering, whether you should wear the FP a bit more and get it re-polished at some point in the future. The advocates of FP claim the ease with which it could be redone as one of its strength.

I also wonder what is wrong here. In half a year the polish should still be able to offer sufficient protection of the wood. If I was still living in Scotland, I would try to get an opinion from and consult with James. Scotland to Yorkshire isn’t that far, isn’t it?
The polish has worn considerably in high contact areas (I don't think it was especially well put on initially). I could put up with it another while but it's a bit ugly.

Which James in Yorkshire? I live in Aberdeen so that's a long journey (Glasgow's bad enough but just about doable in one day).
James Lister. He used to be one of our moderators. Has his own workshop and teaches guitar making at a college. He seems quite knowledgeable regarding FP. I have a high regard for his contributions.

If you say your FP wasn’t a good job to begin with, then this is another argument to have it redone.

Conall
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Re: Is French Polish that much better aurally?

Post by Conall » Thu Sep 12, 2019 12:30 pm

joachim33 wrote:
Thu Sep 12, 2019 7:02 am
Conall wrote:
Thu Sep 12, 2019 6:45 am

Which James in Yorkshire? I live in Aberdeen so that's a long journey (Glasgow's bad enough but just about doable in one day).
James Lister. He used to be one of our moderators. Has his own workshop and teaches guitar making at a college. He seems quite knowledgeable regarding FP. I have a high regard for his contributions.

If you say your FP wasn’t a good job to begin with, then this is another argument to have it redone.
Ok thanks, I might try him if I can't get a luthier closer to me to take on the job.

Obviously I should have taken it up with the maker of my guitar, particularly when the polish started wearing off. Initially the FP wasn't brilliant but I put up with it not realising it would wear off so quickly. I was desperate to start playing the guitar and I didn't want the hassle of sending it back to Sweden. I could still do so but I am only now getting to grips with the 11 strings & am working towards a solo & duo concert next year so I really don't want it away too long. Besides which I've more or less decided I don't want FP - or if I do go for that it will only be the soundboard & varnish for the rest if that's doable.

In an ideal world I would have commissioned a guitar closer to home & been able to bring it back if necessary but experienced makers of extended range guitars are few & far between in the UK (never mind Scotland) & my Swedish maker has lots of ER guitars under his belt & it shows with my guitar because it's balance, tone & volume is very good - at a good price - despite the less than satisfactory FP.

Conall
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Re: Is French Polish that much better aurally?

Post by Conall » Thu Sep 12, 2019 12:33 pm

Alan Carruth wrote:
Wed Sep 11, 2019 6:21 pm
I'm not sure what's available outside of the US. Several luthiers have used Pratt & Lambert's #38 varnish for some time with good results. It's a 'short' oil varnish, and gets reasonably hard. I've been using Murdoch's 'Ure-Alkyd 500' varnish from Sutherland-Welles Co. recently. It can be problematic on some tropical woods, where the oils interfere with drying. It goes on thinner than most, is quite hard (which some might thing a draw back) and looks particularly nice. I have used a number of other varnishes over the years, usually going to some new brand when the one I've been using is discontinued for some reason. They all have advantages and drawbacks, and you have to learn to work with each one as it is. Keep in mind that 'varnish' is a class of materials, as 'wood' is: the name subsumes a wide range of different things.
Ok that all sounds useful, thanks Alan. I'll ask local luthiers what they use other than FP & will mention your varnishes although no doubt they have their favourites. I may also ask if FP on soundboard alone (& varnish elsewhere) is worth considering.

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Re: Is French Polish that much better aurally?

Post by Alan Carruth » Thu Sep 12, 2019 6:27 pm

Again; many people seem to have alkaline sweat, which takes of the shellac very quickly, even when it's a decent coating. I've seen people who could take the back if the neck to bare wood in six weeks.

FP is pretty much simply applying shellac with a pad. It's tricky to get a really fine finish with it, but if your objective is simply to patch up worn spots you could probably learn to do that yourself. The shellac solution used is quite thin; typically a 'two pound cut', which is 2# of dry shellac to a gallon of alcohol, or the equivalent. The best pad I've found is a ball of wool with a linen cover. The pad is barely dampened with shellac, and wiped on using smooth, continuous strokes. The biggest trick is to never allow the pad to stand still on the surface, even for a second. Think about an airplane doing 'touch and goes'; practicing landing and taking off without ever stopping. If the pad stops it will stick, and can leave an imprint, or even lint in the surface. You learn to modulate the pressure and speed of the pad depending on how much shellac is on it, and how wet it is (the relative concentration of alcohol). With a bit of practice you can get a pretty acceptable surface that way. One of the beauties of FP is that it's hard to make a mistake that can't be recovered from. One key is to never try to force it: if it's not working the way you want, walk away for an hour or so.

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