Luthiers outsourcing work

[Bruce Sexauer]

Thank you, Tim.

[JamesO]

I wish it were possible to "like" posts here, because these have been two incredibly helpful posts for me, Tim. Thank you!

[Tim McKnight]

Hi Bruce and James,

I am glad that my long winded rambling was of some help to you even if in a small way. This is just another plus of our community in that there are few secrets and builders are usually very open to sharing experiences, knowledge and wisdom.

I intended to mention this earlier but it slipped my mind until today. Someone, perhaps Alan, mentioned earlier in this thread that finish adds both mass and stiffness to vibrating surfaces. I had one of those "Aha" finish moments while studying with Ervin. He had us measure the deflection of two of our tops that we had thicknessed to a certain deflection measurement. [Deflection is the measured distance that a top bends under a given load of weight. Deflection testing is one way of physically measuring a top's stiffness, prior to adding any braces to it.] We wrote the deflection measurement on the corner of each top. We then added a very thin coat of shellac sealer to one side of only one top then set both tops aside for the day.

The next morning he asked us to measure the deflection of each top again to see if anything had changed. The bare top measured the exact same deflection. The sealed top didn't. It's deflection distance was considerably less which resulted in the top being measurably stiffer. This [Aha] exercise amazed me how just one super thin coat of finish could change the stiffness of an unbraced top.

So how does this information contribute to this discussion? For every coat of finish that is applied to the guitar's surface, each and every coat changes the way the guitar's vibrating surfaces move and the original voice of the instrument is certainly not the same as it was in the white. Each coat of finish adds additional stiffness to the wood. As stiffness increases so does a treble response bias, usually at a loss of bass response.

Not only do additional coats of finish change the instrument's voice, so does the particular type of finish contribute to the whole. Varnish and some urethanes are generally more flexible and resilient. Those types of finishes don't increase the stiffness as much as Polyester finishes, which are at the opposite end of the stiffness spectrum. If a flexible finish and a stiff finish were applied individually to two different instruments, to the same final thickness, Varnish and Urethanes would add the least amount of stiffness to the wood. While Polyesters would add more stiffness and usually more mass due to Polyester's higher solids content.

Some might argue that PE can be applied as thin or thinner than other finishes but I have not seen that to be the case in my experience. Polyester will always add more stiffness due to the inherent added hardness of the finish. Case in point was mentioned earlier when Alan refinished some Ovation (polyester / epoxy) guitars the voice significantly changed.

When a builder outsources the finish process they loose control of the instrument's voice. That control is put into the hands of the finisher. For example finisher A adds 5 coats of lacquer to a guitar, finisher B adds 10 coats and finisher C adds 15 coats. Which instrument will sound the most different? Finisher A's 5 coats of lacquer would have the least effect on the vibrating surfaces while Finisher C's 15 coats of lacquer would have the most stiffening effect on the tone of the instrument. There are no standards in the finish industry. 5 Coats of finish can be shiny to the eye and so can 5 coats of finish.

Some builder's have developed a long and lasting relationship with an outsourced finisher and they know their work and how thick their finish is applied [on average]. For many, this business model may work well for them. However, if your usual Finisher A is booked up and you need to have a guitar finished quickly for an upcoming show and Finisher C can get your guitar done in time, they may be taking a risk that could lead to a significant change in the instruments voice as compared to what they are used to?

Please don't read anything negative into my reply because I don't mean to bash anyone who outsources their finish process because it certainly seems to work for many builders. Some builders can't do their own finish work for health reasons or because the location of their shop doesn't permit them and they have no other choice. Please consider my reply as an attempt to share information that may or may not be worth the price you paid for it

[IBKuz]

Originally Posted by Tim McKnight

Hi Bruce and James,

I am glad that my long winded rambling was of some help to you even if in a small way. This is just another plus of our community in that there are few secrets and builders are usually very open to sharing experiences, knowledge and wisdom.

I intended to mention this earlier but it slipped my mind until today. Someone, perhaps Alan, mentioned earlier in this thread that finish adds both mass and stiffness to vibrating surfaces. I had one of those "Aha" finish moments while studying with Ervin. He had us measure the deflection of two of our tops that we had thicknessed to a certain deflection measurement. [Deflection is the measured distance that a top bends under a given load of weight. Deflection testing is one way of physically measuring a top's stiffness, prior to adding any braces to it.] We wrote the deflection measurement on the corner of each top. We then added a very thin coat of shellac sealer to one side of only one top then set both tops aside for the day.

The next morning he asked us to measure the deflection of each top again to see if anything had changed. The bare top measured the exact same deflection. The sealed top didn't. It's deflection distance was considerably less which resulted in the top being measurably stiffer. This [Aha] exercise amazed me how just one super thin coat of finish could change the stiffness of an unbraced top.

So how does this information contribute to this discussion? For every coat of finish that is applied to the guitar's surface, each and every coat changes the way the guitar's vibrating surfaces move and the original voice of the instrument is certainly not the same as it was in the white. Each coat of finish adds additional stiffness to the wood. As stiffness increases so does a treble response bias, usually at a loss of bass response.

Not only do additional coats of finish change the instrument's voice, so does the particular type of finish contribute to the whole. Varnish and some urethanes are generally more flexible and resilient. Those types of finishes don't increase the stiffness as much as Polyester finishes, which are at the opposite end of the stiffness spectrum. If a flexible finish and a stiff finish were applied individually to two different instruments, to the same final thickness, Varnish and Urethanes would add the least amount of stiffness to the wood. While Polyesters would add more stiffness and usually more mass due to Polyester's higher solids content.

Some might argue that PE can be applied as thin or thinner than other finishes but I have not seen that to be the case in my experience. Polyester will always add more stiffness due to the inherent added hardness of the finish. Case in point was mentioned earlier when Alan refinished some Alvarez (polyester) guitars the voice significantly changed.

When a builder outsources the finish process they loose control of the instrument's voice. That control is put into the hands of the finisher. For example finisher A adds 5 coats of lacquer to a guitar, finisher B adds 10 coats and finisher C adds 15 coats. Which instrument will sound the most different? Finisher A's 5 coats of lacquer would have the least effect on the vibrating surfaces while Finisher C's 15 coats of lacquer would have the most stiffening effect on the tone of the instrument. There are no standards in the finish industry. 5 Coats of finish can be shiny to the eye and so can 5 coats of finish.

Some builder's have developed a long and lasting relationship with an outsourced finisher and they know their work and how thick their finish is applied [on average]. For many, this business model may work well for them. However, if your usual Finisher A is booked up and you need to have a guitar finished quickly for an upcoming show and Finisher C can get your guitar done in time, they may be taking a risk that could lead to a significant change in the instruments voice as compared to what they are used to?

Please don't read anything negative into my reply because I don't mean to bash anyone who outsources their finish process because it certainly seems to work for many builders. Some builders can't do their own finish work for health reasons or because the location of their shop doesn't permit them and they have no other choice. Please consider my reply as an attempt to share information that may or may not be worth the price you paid for it

Tim, as in all your posts this is very informative, thoughtful and insightful information. It is obvious you have investigated this aspect of your build process thoughly over your career as a luthier. As you seemingly have with all aspects of your build process, which is evident in your other posts describing your rational for working the way you do.

With this info, I was wondering if you have determined if the layering of finish is a linear relationship? In your above example of Ervin's lesson, if you added one more layer of shellac, does it stiffen the material a set amount, such that a third layer would give a predictable decrease in deflection? I would expect that it is not linear, but thought I would ask. I was also wondering if there was a sweat spot for each different finish where the number of layers does not make a big difference either way? As an example, between 5-7 layers of urethane gives essentially the same result. I suspect you utilize the sanding process to mitigate/control this aspect of the finish process.

I also wish to add that I hope no one took offence to my earlier post and that I think that all luthiers should outsource their finishing work. I had hoped my comment about "if viable" would not make it seem that I was making this comment as a absolute statement. I have learned in my own experience as to the importance of good health to the quality of our lives, and have started to make changes in the way I work and just wish for others to reflect on this and on their own established habits.

[redir]

Interesting. So for Spanish guitars where luthiers strive so hard to have loud trebles and hardly have to work hard at all to get a good bass response, sounds like a PE finish would be the best? Yet FP is the standard on the very best instruments.

[TEK]

Thanks Tim and everyone else for that matter for contributing to this thread. As a guy trying to soak up as much information about building as I can, information like this is invaluable. I appreciate your willingness to share the things you have learned over many years. It has sure cut my learning curve down some. Thank you!
On my last build I was asked about the option of sending it out to be finished be a professional. Although I know that he could do a better job than I can at this point, I chose to finish it myself. Mainly because the part inside of me that drove me to building in the first place, drives me to want to do everything involved in the process. Maybe if I had so many orders that I was backed up for some period of time I would reconsider and farm out the finishing. But for now I keep driving myself crazy trying to learn it all.

Travis

[Guitars44me]

A big thank you to all who have posted here, and especially Tim McKnight. It is indeed obvious that you have really thought this through!!!

Another plug here for Tony Furguson, who specializes in finish work for the Kinnaird bros. and many others. His work is spectacular. I have had a couple VERY nice guitars with varnish and One with French Polish and my JKs with Tony F finish sound better to me. Of course that is just me, but my wife agrees!

John K says if Tony retires, so is he! Personally I hope they both work forever!!! Hahahahaha

You luthiers all deserve many kudos! Carry on and may your herds increase!!!

Cheers

Paul

[terken]

Tony has done my finishes for a long time. He is spectacular. Tops are usually less than .003 in the bridge area.

[Alan Carruth]

Tim wrote:
" Case in point was mentioned earlier when Alan refinished some Alvarez (polyester) guitars the voice significantly changed."

I mentioned working on the tops of some Ovations, finished with epoxy, but not Alvarez guitars. Other than that minor matter those were very useful posts.

Finish does add both stiffness and mass, but different amounts of each, and maybe not always in the same way even for a given finish. In the violin world they say that it's the first two or three coats of finish that make the most difference; after that it doesn't matter as much. This makes sense when you think about it.

The stiffness added is a function of the Young's modulus (E) of the finish and the film thickness, all of this relative to the E value and thickness of the wood it's on. Most finishes add significant stiffness across the grain in softwoods, but much less along the grain simply due to the difference in E value for the wood itself. Schleske listed the stiffness change for all of his samples, again with the sample thickness and amount of applied finish the same each time. Some of the more flexible ones, such as oils, added no stiffness to speak of, even across the grain in softwoods. Others; particularly nitro and shellac, added a lot.

The first coat of finish makes a pretty big difference if it's got a much higher E value than the wood, even if it's thin. The next coat doesn't do as much simply because it's probably really thin as compared with the wood thickness, and each coat after that has less of an effect. This could all be calculated if you had the math: I don't. It would be a lot easier if you put finish on both surfaces.

On the other hand, each coat of finish adds mass. Mass cuts down on responsiveness and power, so you like to avoid it, at least on a top. At some point, and probably after only a few coats of finish, the added mass has more of an effect than the added stiffness. Hence the thought that it's the first couple of coats that count the most.

Damping may be a bit harder to generalize. Resins, and particularly nitro and shellac in Schleske's tests, have much lower damping than most woods, so adding a coat of those can actually decrease the overall damping of the system. Oils have high damping, add in general, and the more the worse. He didn't test any water born finishes, but I suspect that they have fairly complicated structures when cured, and may add a lot of damping. Certainly the one we tried that I mentioned did. Some of them also build fast, adding mass.

Which brings us back to the 'less is more' mantra. Any tonal benefit the finish confers comes in with the first couple of coats, after which you're more likely to see harm than good.

It's a pity, then, that the market concentrates so much on the appearance aspect of finish: a wash coat of shellac is really all you 'need' to protect the wood, and it's easy to renew when it wears. The market wants a finish that's smooth enough that when a fly lends on the guitar he skids off and breaks a leg. I know of only two ways to get that:
1) put on a lot of finish and buff it until it's shiny, or
2) put in a lot of hours building up lots of thin coats.

In option two it's all about surface prep, keeping in mind that the coat you just put on is the surface for the next one, and may need to be leveled out. Option two is the only one that results in a thin finish that might be able to pass the 'fly test', at least until the wood under it moves. Too bad it takes so much time and effort.

[redir]

So that begs the question then about using different finishes. For example shellac as a sealer. That technically is the first coat and so according to Alan's hypothesis is the one with the most affect. So then on top of that we often put Nitro, Varnish, Water base and so on. If those top coats are even less important then if you always seal with shellac first then it's like all the benefits of FP with stronger top coats

[Jabberwocky]

Farmed out fretwork, inlays, binding, rosettes, ornamental aspects I have no issues with as a buyer. Frets require replacing when they wear out. Consider it maintenance. I won't send the guitar back to the luthier for replacing of frets. He cannot do a job better than a competent guitar repairman. If that is true, then there is no requirement that the luthier install the original frets.

There is no one set-up that suits everybody so I expect my guitar to be set-up locally for me when I get it. It will probably take a few goes before I am happy. Local climate shenanigans will necessitate that. So, yeah, I am all right if the luthier farms out his set-ups, too.

The luthiers I have talked to enjoy finishing their guitars. They see finishing as a capstone to the build. Let's be honest: we are first drawn first by the cosmetics of a guitar and then its sound followed by its playability. Nobody wants his guitar to look like Trigger except for Willy Nelson. I choose French Polish or oil varnish when I can because 1) the luthier enjoys the FP/varnish process; 2) it is safe for the luthier's health. I don't want my luthier to suffer for my guitar so if he chooses to farm out his finishing to a specialist with the equipment for safely finishing in nitro I am all for it. I gotta trust that the luthier upholds the highest standards and will choose his partners with the utmost care. After all, if his finish partner has low standards, his guitars will sound like crap.

Taken to the limit, when a luthier signs only the label and builds nothing himself, congratulations, that is the day a boutique manufacturer is born. No issues with that either. Boutiques can be great guitars, too.

In closing, I don't mind the luthier farming out the gruntwork aspects of the build when they free up his time for aspects of the build that count. Ornaments like inlay are frou-frou that I don't care about but frou-frou often takes up as much time as the actual build. Finish contributes to the sound and I would expect a luthier worth his reputation to find a partner who meets his standards. That said, the luthiers who use safe finishes such as FP or oil varnish mainly enjoy the processes. The ones who farm out usually finish their guitars in nitro.

This is from my perspective as a buyer and player. It is the end result that counts.

[mcduffnw]

Originally Posted by Jabberwocky

Farmed out fretwork, inlays, binding, rosettes, ornamental aspects I have no issues with as a buyer. Frets require replacing when they wear out. Consider it maintenance. I won't send the guitar back to the luthier for replacing of frets. He cannot do a job better than a competent guitar repairman. If that is true, then there is no requirement that the luthier install the original frets.

Taken to the limit, when a luthier signs only the label and builds nothing himself, congratulations, that is the day a boutique manufacturer is born. No issues with that either. Boutiques can be great guitars, too.

In closing, I don't mind the luthier farming out the gruntwork aspects of the build when they free up his time for aspects of the build that count. Ornaments like inlay are frou-frou that I don't care about but frou-frou often takes up as much time as the actual build. Finish contributes to the sound and I would expect a luthier worth his reputation to find a partner who meets his standards. That said, the luthiers who use safe finishes such as FP or oil varnish mainly enjoy the processes. The ones who farm out usually finish their guitars in nitro.

This is from my perspective as a buyer and player. It is the end result that counts.

So Jabberwocky...

If you are "fine" with the luthier farming out all of the above noted steps...or potential steps...in a given guitar build process in order that they, the luthier, may focus their time and talents and efforts on the steps/tasks that "count" towards the successful end result...then what are those steps that in your mind really count and are actually worth the luthiers time, and reality, in your money that you are paying them?

Whenever we have had threads on the AGF where we discuss things like what the luthier does actually work on, as opposed to what they farm out, or how much they make and build by hand, as opposed to buying as pre-made parts or creating by machine tooling process, many folks say they don't mind the farm out work, or the use of pre-made parts or parts that are machine made instead of hand made. These folks say that they don't care to have, or don't want the luthier spending his time and talent on non essential/important steps in the build process, they want the luthier to concentrate their efforts/talents on the really important steps.

So...what are these essential/important steps? Voicing the top as a free plate, then with the bracing, then perhaps joined with the back and sides as a unified sound box?

If you have watched the Dana Bourgeois videos on voicing the top or read other builders descriptions of their voicing process, you might note that it is not an especially slow, long drawn out process. I think Dana has said that he can voice a top...shaving and tuning the braces...in about 20 minutes...maybe 30 minutes, and I have read other lutheirs accounts and again, it is not like an hours and days long process.

Neither is joining up the soundbox, carving the neck...especially if done by some measure of machine tooling work...setting/aligning the neck into the body, aligning and gluing the bridge.

So if you...and by "you", I mean anyone who may feel in some way similar about these things as you do Jabberwocky... are mostly concerned with the top and soundbox voicing aspect...as where you want the luthier to concentrate their time and talent, and not waste it on menial tasks, does that mean that if it only takes the luthier an hour or two for voicing/tuning the top, another hour or two to voice/tune the completed soundbox, that if you are paying $6K, 8K, 10K, 12K or more for your guitar, that you feel/are OK with knowing that you may be paying quite a bit of money for a very small, or perhaps, concentrated amount of actual build time within the whole building process timeframe?

duff

[justonwo]

I guess it would be useful to ask what elements we are talking about. I don't see that anyone has done that yet. The ones that come to mind are roughing out the neck by CNC, perhaps having the bridge made by CNC, and in some cases having the frets leveled by Plek? I'm not sure there is much else, though I suppose one could farm out the entire final setup. I know that, for example, one of my guitars was Pleked because it lacks an adjustable truss rod and needed to be spot on. The setup is flawless. The other guitar I own that has no adjustable rod was done by hand, and it has buzzes and has high spots. I'm sure that builder put a lot of time and energy into the setup, but you simply can't exceed the precision of a Plek.

As for the other stuff, none of those operations really bother me. The builders that use them still only pump out 12 guitars a year or so. I'm pretty sure they don't spend 20 days out of the month on the beach.

[iim7V7IM7]

Originally Posted by justonwo

I guess it would be useful to ask what elements we are talking about. I don't see that anyone has done that yet. The ones that come to mind are roughing out the neck by CNC, perhaps having the bridge made by CNC, and in some cases having the frets leveled by Plek? I'm not sure there is much else, though I suppose one could farm out the entire final setup. I know that, for example, one of my guitars was Pleked because it lacks an adjustable truss rod and needed to be spot on. The setup is flawless. The other guitar I own that has no adjustable rod was done by hand, and it has buzzes and has high spots. I'm sure that builder put a lot of time and energy into the setup, but you simply can't exceed the precision of a Plek.

As for the other stuff, none of those operations really bother me. The builders that use them still only pump out 12 guitars a year or so. I'm pretty sure they don't spend 20 days out of the month on the beach.

Aside from the operations that you outlined, there other small things. Some that come to mind are:

- Some luthiers slot their own fingerboards, others purchase slotted blanks
- Some luthiers make their own linings, others purchase them
- Some luthiers make their own marquetry, others purchase them
- Some luthiers make their own truss rods, others purchase them
- Some luthiers do their own inlays, others farm them out to inlay specialists
- Some luthiers turn their own pins, others purchase them
- Some luthiers make their own tuner buttons, others purchase them
- Some luthiers have assistants performing many fabrication operations under their oversight
- Some luthiers make their own custom dish (solera) and others purchase them from suppliers
- Some archtop luthiers carve their own tops and backs, others purchase them rough shaped

None of these methodlogy distinctions "bother" me, but I do have an extra level of artisan admiration for those luthiers who take the vertically integrated approach.... Given my druthers, I like my guitars built as much as possible by the person whose name is on the label as opposed to an assistant or apprentice. Items that are subbed out or purchased can vary based on their approach.

[Guitars44me]

Hey Juston. As for exceeding the precision of a Plek machine....

I have had a few that were pleked now. And dozens set up, quite a few fret dressed and a handful refretted by Tim Luranc (RT, Taylor Repair). I prefer Tim's work to the Plek machine! Of course he knows me and my style of playing very well now. The poor fellow has done a few gigs with me! And I have done a couple with him... He has probably done more frets than almost anyone alive, considering he did the fret installs for Taylor for years in the 70s and 80s, prior to them getting machines for the job. Three or four a day, five days a week, 48 weeks a year, for years! No wonder he is in such demand.

Also, I must say I like John Kinnaird's approach to building. He has no interest in repeating anything. His website mentions the wonderful feel of a plane on a neck. Now I am hooked on having what I order built just for me.

Thanks to all the wonderful Luthiers turning wood into music!

Cheers

Paul