French polish versus varnish

[bho]

Hello,

In considering French polish versus varnish, does one provide for a better tone? Does one look better than the other? Any other upsides/downsides of one versus the other besides French polish damaging more easily?

Thank you.

[M Hayden]

French polish is very Thin layers of shellac laid on with a tightly bundled wool/linen cloth. It’s beautiful but doesn’t have the film thickness and (often) the finish hardness of varnish (or solvent finishes like nitro lacquer).

FP generally doesn’t show witless lines bc it’s all one layer of shellac, essentially. Varnish can have witness lines if the applied isn’t careful and sands through coats.

In terms of sound, I’ve heard great-sounding instruments with every possible finish - nitro, FP, varnish, water-base poly, oil-base poly, light-cured polyester....it’s the guitar, not the finish.

[Bruce Sexauer]

I am an oil varnish proponent. IMO French Polish is inadequate for real world guitar finishes. It requires ongoing upkeep and maintenance unless the guitar is babied in a way I cannot imagine my average customer managing. I am uncomfortable around most people who are than anal, and I am not now nor will I ever be one of them.

Oil varnish has its own idiosyncrasies. On the plus side it is abrasion resistant and will not be affected by nearly any solvent it may encounter, and it NEVER cold cracks. By "it" I mean any of the oil varnish variations I have used over my career. On the other hand, part of the reason OV sounds superior (if you think it does, as I do) it the is that of the woodhat it add less structure to the guitar than Nitro Cellulose or UV cure finishes. This means that although tougher in some ways, it is also softer, and there for less like a pick guard, and the hardness of the surface is that of the wood itself, more or less. More care in handling is required if one is dent averse. On the other other hand, it lasts for hundreds of years, unlike Nitro which outgassed until it disintegrates, usually in under 100 yers.

[SprintBob]

Originally Posted by Bruce Sexauer

I am an oil varnish proponent. IMO French Polish is inadequate for real world guitar finishes. It requires ongoing upkeep and maintenance unless the guitar is babied in a way I cannot imagine my average customer managing. I am uncomfortable around most people who are than anal, and I am not now nor will I ever be one of them.

Oil varnish has its own idiosyncrasies. On the plus side it is abrasion resistant and will not be affected by nearly any solvent it may encounter, and it NEVER cold cracks. By "it" I mean any of the oil varnish variations I have used over my career. On the other hand, part of the reason OV sounds superior (if you think it does, as I do) it the is that of the woodhat it add less structure to the guitar than Nitro Cellulose or UV cure finishes. This means that although tougher in some ways, it is also softer, and there for less like a pick guard, and the hardness of the surface is that of the wood itself, more or less. More care in handling is required if one is dent averse. On the other other hand, it lasts for hundreds of years, unlike Nitro which outgassed until it disintegrates, usually in under 100 yers.

Good info, thanks Bruce.

[Dustinfurlow]

Originally Posted by Bruce Sexauer

I am an oil varnish proponent. IMO French Polish is inadequate for real world guitar finishes. It requires ongoing upkeep and maintenance unless the guitar is babied in a way I cannot imagine my average customer managing. I am uncomfortable around most people who are than anal, and I am not now nor will I ever be one of them.

Oil varnish has its own idiosyncrasies. On the plus side it is abrasion resistant and will not be affected by nearly any solvent it may encounter, and it NEVER cold cracks. By "it" I mean any of the oil varnish variations I have used over my career. On the other hand, part of the reason OV sounds superior (if you think it does, as I do) it the is that of the woodhat it add less structure to the guitar than Nitro Cellulose or UV cure finishes. This means that although tougher in some ways, it is also softer, and there for less like a pick guard, and the hardness of the surface is that of the wood itself, more or less. More care in handling is required if one is dent averse. On the other other hand, it lasts for hundreds of years, unlike Nitro which outgassed until it disintegrates, usually in under 100 yers.

Interesting to read. I really love the organic feel of the Oil Varnish I have felt on several of your guitars now, Bruce. Would take it over any of the French polish finishes any day, as the guitar is meant to be played in my opinion, and not worried about.

[Simon Fay]

Some folks have sweat that does wear away shellac quite quickly and which can cause problems on the neck. Many others can have a French Polish neck that shows little wear even after a few decades. Finishes like varnish and the modern catalyzed finishes are definitely more user friendly in regards to sweat and various chemicals and solvents.

On a very responsive and vibrant guitar, French Polish is the gold standard for tone - this is certainly the case in the classical world where the top is much more finicky than a steel string top. I think a thinly applied oil varnish pretty much matches shellac for tone and I would put it in the same tier. I would say that a very thin 2mil lacquer or urethane finish will also come very close to French Polish for tone but they must be incredibly thin and expertly applied. I have learned from personal experience, that even a thin polyester finish kills the tone somewhat - it's not a massive effect but it is noticeable. So even though polyester offers the best protection and durability out of all the finishes, it will restrict the potential of your guitar.

The one big advantage French Polish has going for it is the incredible repairability. If the finish is worn down in a certain area or you have some light scratches - you simply add some more and you've can restore the finish to new condition. The only other finish that is as repairable is nitrocellulose lacquer but the repair process is much more involved and nitro begins to decay after a number of decades.

I think oil varnish is an incredible finish - the only downsides are that it can be challenging to get the same level of cosmetic perfection as a lacquer finish, that it yellows noticeably over time, and that it is not easily repaired. It also imparts an amber tint to the guitar right from the beginning. I think this yields a lovely look to many hardwoods but don't love how varnish looks over Spruce or other light woods like Maple.

The downsides to French Polish are that it tends to be quite soft when the finish is new but it does become noticeably more durable as it ages. The other downside is that it can be quite difficult to achieve lacquer like perfection. As mentioned, some individuals will have sweat that tends to wear away the finish, which will necessitate occasional reapplication of the finish.

There is no question in my mind if I was building a guitar to last well past my lifetime that I would chose a French Polish finish. Even though it is a delicate finish, it's the finish that will look the best 100 years from now and be able to be easily repaired and maintained !!! Also, shellac becomes much more solvent resistant as it ages. In my opinion, it is a superb finish but does require more care than other finishes, especially when the finish is brand new. Additionally, some folks will find their skin chemistry isn't well suited for a shellac finish.

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IMO, both French Polish and oil varnish are delicate finishes that need to be cared for. Compared to shellac, varnish is definitely more solvent resistant and scratch resistant but much harder to repair. If you are accustomed to a durable modern finish - both of these finishes will require you to be more careful with your instrument. The same can be said about nitrocellulose lacquer as well but shellac is the most delicate of the bunch.

Having used both oil varnish and French Polish - my personal preference is for French Polish. You just have to be careful with the finish and wipe the places your skin contacts with a clean, cotton cloth after you're done playing. You have to be aware that it doesn't offer great scratch or dent protection. You have to be aware that it is a hand rubbed finish and will not be quite as cosmetically perfect as a showroom lacquer finish (although, I can get it pretty darn close). Lastly, you may need to send the guitar back for a new coat of shellac periodically during it's lifetime. One customer that went with a French Polish finish didn't realize how delicate the finish was and scratched it up quite a bit on the top during it's first year - he sent it back to me and a couple weeks later it went back out to him looking brand new again. That said, I also really like oil varnish and think it is a superb finish.

[Alan Carruth]

What Bruce said: we're both oil varnish guys..

Keep in mind that 'varnish' is like 'wood'; a name for a broad class of materials. Varnishes can be almost as different from each other as spruce is from ebony.

FP is 'best' in the sense that you can get a protective film with a thinner coating than almost any other finish, and with finishes, less is better. But you do have to understand that no finish, no matter how hard and tough, will prevent dings if it's really thin. You do have to treat your guitar well to keep it looking good.

Shrinkage in nitro is not just a matter of 'outgassing', at least, not in the sense of solvent loss. Nitro is chemically unstable, the little brother to a high explosive. About 1/6 of what's there, the part that's actually nitrated, can break down overt time into some sort of oxide of nitrogen, water and CO2. The nitrous part then combines with water in the air to form nitric acid, which reacts with lots of things in unhelpful ways. Museum conservators rate nitrocellulose as a hazard that has to be isolated from the rest of the collection to avoid damaging it. There's one other plastic that reacts similarly: cellulose acetate, which they used to use as binding. As these things break down the film/binding shrinks. Generally speaking, the thicker the parts/finish the faster the break down.

[justonwo]

I'm a big fan of varnish and nitro finishes because I think they offer a great combination of tone and durability. I have a number of guitars with both and don't find them deficient in any way. I've played a number of guitars with French polish over the years, and I can't say I remember them being particularly stand-out because of their tone. What I DO remember is their owners being extremely anxious anytime anyone touched their guitars.

I think I'd be fine with a French polished guitar because I'm not that hard on instruments and the marred finish wouldn't really bother me, but I've never felt like it was tonal "must have."