Official Luthiers Forum!

After gifting my first 9 guitars to sons, brothers and godsons, I built the last 3 acoustic models for myself and play them often. The gifted guitars used durable finishes such as Nitro, USL, KTM-9 and Catalyzed Polyester. After years of daily play they continue to look good with normal wear and tear and virtually no maintenance.

The 3 that I made for myself were all French Polished Shellac and after overcoming the learning curve actually came out quite nicely (Thank you Michael, Robbie and Colin). And they would remain beautiful guitars except for the fact that I play them. The neck was the first area to show wear which required an occasional few swipes with 400 grit and about 30 minutes of several FP sessions in order to restore the surface to its original condition. After a period of time, I sanded off all of the shellac from the neck and applied Danish Oil which I love. It requires no routine re-finishing regimen and feels slick to the touch.

Next problem areas on the body are where it came in contact with my arm and torso. Those areas began showing a deterioration which requires similar maintenance but taking much longer to restore. The bottom line is that I'm suffering from FP remorse and am considering refinishing all three guitars in Catalyzed Polyester...are you listening, Joe!? Because I don't wish to change the sonic properties, I am considering leaving the tops as is and apply Polyester to the neck, back and sides.

I was wondering if anyone had ever done such a refinishing and was hoping to get answers to a few questions:

1) Will I hear a difference in sound if I leave the top as is and Poly finish the rest of the guitar?

2) Will I hear a difference if I Poly finish the top as well?

3) With the neck having Danish Oil what method is required to prepare that surface for Poly?

4) Will I need to sand back the shellac on the body to bare wood...or would roughing up the surface with 220 be sufficient before starting the Poly procedure?

TIA

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JJ
Napa, CA
http://www.DonohueGuitars.com

JJ, Logic says that if the finish is thin enough (any finish) then there should be no affect on the tone/sound or projection of the instrument. This is a HUGE can of worms to open up though. I predict very passionate posts in this thread in a jiffy!

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jw ( o)===:::

The neck I understand because I have issues with FP necks as well but the body I assume that you have sheen issues where your arm rests. Please don't take this wrong, but this fall under the MGAMLN syndrome (My Guitar Must Always Look New) a simple wipe down after play will in 99.9% of the cases eliminate shellac wear away where the arm rest but yes the sheen will need restored if you desire it to always look brand spanking new.

I am not giving you a hard time about this. I do understand. But the dulling of the sheen on a shellac surface does in no way diminish the protection the finish is providing. And it is easily restored.

If you are desiring a high sheen that will not diminish with wear and playing then maybe you do need to think about a cat poly or cat urethane finish.

Now do you need to take the shellac back? If you want to add no more dampening then yes you will. Regardless you will change the guitar sonically a tad. Maybe you will notice maybe not but cat poly and cat urethane are a bit less flexible than shellac but are many times more resilient in holding sheen.

I feel your pain, JJ...

However, knowing how shellac can be affected by areas of friction (the neck), I finish it with water-based lacquer, and body is French Polished. My cittern has been played almost daily for over a year and apart from the usual minor dings, the polish is still holding up.

Tru Oil adheres to shellac and buffs to a pretty decent shine...

Michael...you're probably right about wiping down after playing. I'll admit I'm remiss in doing so but I never know when I'm finished! I have only one guitar out of its case at a time and it sits on a stand. I play for a few minutes and may not get back to playing for another hour. I may then play for an hour or so and take another break ad infinitum! So it could be days before I consider myself finished playing and ready to play one of the others! I know...bad habit and lousy discipline.

Ever since Joe opened his shop I have had the opportunity of dropping in occasionally and seeing the brilliance of his finishes. As a result, I believe I'm beginning to suffer from "Shine Envy". I'll admit it...I am developing an inferiority complex and I have a need to better show off my wood.

Sammy...I'm not so much worried that the surface is not being protected, it's just that the level of protection is so much better with the poly. I'm still going to leave the top FP'd (I think) but I'm fairly convinced that I will upgrade the back & sides.

So let's assume that I'm serious about re-finishing in Poly...any thoughts on my questions?

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JJ
Napa, CA
http://www.DonohueGuitars.com

I FP the whole guitar on all 6 I've built and haven't had any issues except on one guitar. I know why, I started playing it the next day after finishing it,I just couldn't wait! I think one's body chemistry must come into play. Clinton

Behlen's on the back and sides and FP on the top.

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Doug Mills
Chicago, Illinois

Clinton...I agree that body chemistry way well be the culprit. So much for a healthy lifestyle and diet!

Doug...Did you start out with Varnish and shellac or did you FP the entire guitar first?

I'm not so much concerned with the body prep but I am concerned that the neck's current Danish Oil finish may not be compatible and possibly not accept a poly finish. Remember...this has penetrated the neck wood and cannot be sanded off prior to shooting Poly.

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JJ
Napa, CA
http://www.DonohueGuitars.com

I am coming to the same conclusions that JJ has. French polishing the entire guitar, while pleasurable and fast once one gets the hang of it, does not give very good protection. Individual body chemistry indeed seems to be a factor. I saw a French polished guitar of mine recently that had had a year's worth of daily playing and it looked very good. No imprinting, dulling, etc. Conversely, I got another guitar back (with the same finish) that I loaned to a friend for 5 months and the guitar body looked terrible. The top was OK, but there was dulling, imprinting and a weird place on the bass upper bout with major finish deterioratoin. It took me a while to figure out that it was the player's breath on the upper bout that caused the problem. I watched him play and he routinely brought his head down, looked at the floor, and breathed on the guitar about 2" away from the upper bout. It was very easy to repair. About an hour of touch-up and the guitar looked like new. How many guitarists will want to incur the expense of shipping the guitar back to the maker once or twice a year to have the finish repaired?
I am growing dissatisfied with a finish that will prove unpredictable in the market place. It is disappointing to have all the time spent with careful selection of woods, decorative bindings, purflings, etc, essentially nullified by a crappy looking finish. The French polishing of the soundboard seems to hold up well in all instances, however. Probably because of the limited contact area with the player's body.
I currently have 2 partially French polished guitars that I want to finish with a more durable film on the back, sides and neck.
A question for Joe or Tony: will one of your finishes adhere to a fully cured shellac undercoat?

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Stay with the happy people.
--Reynolds Large

Tom...that guitarist who breathes on his guitar must be drinking some powerful liquor! We all know what alcohol does to a FP finish.

Your concern about whether a poly finish can be applied over a cured shellac surface is exactly my concern as well. Having done Nitro as well as 2 waterbourne finishes where I used shellac as a base coat, I suspect that shellac is in fact compatible...it seems to be specified as a sealer under many finishes. And I suspect that all we need to do is rough up the surface with 220 grit. But knowing Joe as I do, he will be finicky about committing to this unless he already has experience and I'll be he'll want the shellac sanded down to wood. I'm also hoping he will chime in soon.

Perhaps Mario and Rick are lurking and can offer an opinion or 2!

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JJ
Napa, CA
http://www.DonohueGuitars.com

In regard to tone, theoretically there shouldn't be a significant difference between FP and poly. A lot of people like to believe so, but I think it falls under the same type of comparison as a dovetail joint vs. a bolt-on... it's one of those things you can never truly test because you're always dealing with two different instruments and the variables that come with it.

I personally love a guitar with a dull finish. I've never really been into the shiny bling-bling stuff... If you want shine, though, lacquer or poly is probably the better choice.

The answer to your question to Joe and Tony is yes. you will want to take off any polishing via a Alcohol wipe down. keep in mind that you are adding finish thickness

French polish is not unpredictable. It is the oldest most used fine wood finish and has been for centuries. Now predicting if a client has high ammonia or a PH level in their body chemistry that will cause and issue that can be unpredictable. The real note of topic here is a common one. Disappointment in finish “A” because it does not have the attributes of finish “B”

I'm getting excellent results doing a, "21st century FP", with KTM9.

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https://soundcloud.com/jeffreylsuits/he ... -runnin-13

NO,NO,NO,NO)
You can pad on KTM9 but you can not French polish KTM9. KTM 9 will not melt and amalgamate in to a continuous film. You can only pad layer over layer. Padding layer over layer is not French polishing. French polishing required a media that can be solvent melted over and over and over.

So you are padding on KTM9 not French polishing KTM9

I don’t’ mean to sound huffy but there is a world of difference. you can pad on or hand rub most any media. but you are always putting one layer over a setup layer. In French polishing you amalgamate the shellac into one continuous film not layers of film.

The funny thing is I honestly can't tell if he was joking or if he was being serious.

I suspect he was serious. I have about 4 emails from people claiming to French polish with waterborne acrylic lacquer and have encountered such claims to use " 21st century French polish" elsewhere.

Michael is quite right that is not French polishing in any way, shape or form. It's simply applying KTM9 by rubbing one layer on top of another, a French polished surface using shellac is one continuous homogeneous layer.

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

My response was a tad overboard now that I look back and I appolagize. My responce stems back to an on going email conversation I have had with a (to remain nameless) furnishing builder that was advertising his finishes as “21st century French polished finishes”. When I inquired what made his French polish finish 21st century he told me the finish material was waterborne acrylic lacquer in stead of shellac. As we talked I inquired as to how he was able to achieve amalgamation with waterborne lacquer to achieve the ability to French polish as apposed to merely padding layer over layer. Well come to find out he never knew that a French polish finish was a continuous build of a single film as apposed to layer over layer application as he had never done nor studied French polishing. I nicely left the email conversation with links to tutorials and history of French polishing. I do not know if he still advertises his work a s 21st century French polish.


I know many people are not famillure with how French polish works. But some where down the cyber trail someone has coined the phrase “21st century French polish” as a means of describing padded on waterborne finish.

As you can see this drives me batty!!!

But I have taken my meds and I’m ok now

The problems starts with the nomenclature...from my reading on the subject theres nothing much French about it for a start.

JJ, sorry to hear your frustrations with shellac and the FP process. If it makes you feel any better, the classical players will love the look of your guitars after they dull. There is nothing worse than watching somebody on stage with a super shiny guitar that flashes back at the audiences eyes like a 10,000,000 candle power spotlight. In all seriousness, a shellac finish looks great once the sheen has worn a bit, sort of like a classic '59 Les Paul, or an old violin. Most classical players are used to dealing with a delicate FP and so might be a little more careful while playing, but normal wear doesn't look bad at all. I've seen many classical players cut the entire toe off a sock and wear it over the forearm to protect the guitar while playing. I've even seen builders who FP the guitar, then knock the sheen back with 000 steelwool--in some cases it adds a certain warmth to the guitar and not that plasticy, shiny, Takamine looking finish.

Good luck whichever way you decide to go!

John

Edit... I forgot to mention, my old neighbor who owns a music store says the plasticy shiny finishes sell much better than anything else, even when they sound ten times worse. Bottom line, a good player will see through the finish and buy based on sound.

John...I have no doubt that if and when I build a classical, it will be FP shellac. I just have come to realize that I can't get the old expectation of a shiny steel stringed acoustic or electric out of my head. Still, I'm glad I learned how to do the process and look forward to doing it again some day.

I agree that the sound remains the highest priority and I surely don't plan on deviating from that objective.

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JJ
Napa, CA
http://www.DonohueGuitars.com

Are you saying there is nothing French about French polishing?

Well here is brief and condensed history of how French polishing got its name.

Shellac had been used as a finish in Asia for centuries before it imported to Europe in the 1700's. In the late 1700s and early 1800s French furnishing artisans developed the method of building an amalgamated or one continuous film build by means of solvent melting one application of shellac fully into all previous applications. Amazed by the depth and luster of this finish the English furnishing makers quickly nick named this application as French polishing some time in the early 1800's

So the process we know to day as French polishing most certainly derive it’s lineage from the French. Now it is entirely possible and some what likely that Asia had also conceived a similar way of working shellac earlier than the French but no historical record of the type of process has been found there. There are many accounts of how Asia used shellac as a finish prior to the French. But in terms of the process as we know, it most certainly is French polishing.

Sooooo...back to my original question if I may.

Does anyone have an opinion as to how I should prepare the neck surface (now Danish Ol) prior to finishing with Poly? I'm concerned about compatibility since I assume that the DO has penetrated deeper than any surface sanding would remove.

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JJ
Napa, CA
http://www.DonohueGuitars.com