Official Luthiers Forum!

Huh? Who? What? Bear with me for a bit...

With Mr. Stock back to basic functionality after rotator cuff surgery, I've been over at Greenridge a bit less often of late, but managed to catch breakfast with them this past Sunday morning. Mr. Stock handed me his phone and pointed to a text thread from one of his customers (a good player and owner of some nice 1920's through 1943 Martins).

The back-story:

- Greenridge does a presale assessment on a 0-17 a few weeks back... lovely instrument... all-original finish, original bridge which appears to have been undisturbed, and - other than nut, saddle, and frets - complete as delivered in 1938. One lighter spot behind the bridge... on inspection, one of those odd spots that pops up on mahogany-topped guitars from time to time... the last one we had seen hung in a shop window for a few decades, but only got direct sunlight for perhaps a few minutes a day during the winter months. Most notably, a very nice finish with just light play wear, the usual degree of checking on a well-cared-for instrument, and the absurd projection that 80 year old mahogany small bodied Martins seem to possess. Previous owner claimed to have had Mr. John Hall do the neck reset and replacement saddle a few years ago, so no real issues on the structural side.

- Buyer shows up with the usual internet expert-sanctioned paraphernalia and spends a few hours playing and inspecting the instrument. Offer and acceptance with a cash/no conditions sale.

- A day or so after the sale, Greenridge is advised by our customer that the buyer has visited his luthier for inspection, and that that gentleman believes the guitar to have been over-sprayed on the top and possibly the victim of a ham-handed bridge repair which required significant refinish. Specifically, that tech claims he can detect over-spray in the 0.005-0.008 inch deep scratches which were incompletely filled by all that new lacquer which - although not visible under UV and so well done as to show no obvious surface irregularities - must surely be there.

- Our customer cajoles Mr. Stock into a direct call to the buyer's luthier, who claims special expertise as a long-time automotive finisher and solid-body guitar assembler. Mr. Stock - always willing to 'wrestle the pig' - foregoes that pleasure and terminates the call with an agreement to disagree.

- Our customer is advised that if he still feels any burden in what was an unconditional, cash sale, he should suggest a disinterested third party inspect the guitar.

- The buyer calls Mr. Stock directly. After clearing a discussion with our customer, Mr. Stock covers what he considers to be the salient points of his pre-sale inspection findings and again suggests a third party with national reputation if the buyer has any lingering doubts. Mr. Stock also suggests that not every repair tech or luthier should necessarily be considered qualified to assess any and every instrument that arrives on his or her bench.

While we were having our bison huevos rancheros at the Silver Diner Sunday AM, Mr. Stock received a text from his customer that the third-party inspecting shop, selected jointly by the buyer and seller - a Retro-themed Fretted instrument sales and repair shop in Brooklyn, NY - had not only confirmed the accuracy of the Greenridge pre-sale inspection, but had offered to buy the instrument for a few thousand above the recent sale price, and considered the guitar to be one of the nicest of that marque, model, and vintage they had seen.

So what is the Dunning-Kruger Effect and why might it apply here?

Dunning-Kruger suggests that people of limited competence in some particular field of endeavor tend to overestimate their abilities and - no surprise here - very competent people sometimes underestimate their competence. That meta-cognitive task - dispassionate assessment of one's level of competence against objective performance - is linked as much to raw intellectual horsepower as to underlying personality and character. The effect is most succinctly characterized as ' incompetence often includes being unable to tell the difference between competence and incompetence.'

I'm not suggesting that people competent in a given field must always agree, but I've also seen enough botched repairs or complete misses on diagnosis of an instrument's ailments not to discount the Dunning-Kruger Effect as a reason for some of the wonderfully complex messes we saw at Greenridge. My own experience in repair being somewhat limited, my sense of the industry as informed by the more experienced (and competent) luthiers around me is that a not insignificant portion of the work that any well regarded, highly competent shop and staff will see is as a result of other repair shops (or owners/'helpful' friends) mistakenly believing they are competent to carry out a repair, assessment, or other higher-level task. This results in additional monetary cost to the owner for undoing the botched repair, the added cost of repair by someone competent to execute that task, and the opportunity cost for the servicing shop.

Finally, an extension of the Dunning-Kruger Effect is the tendency for those without any degree of competence in a field to see even those of very limited competence as being highly competent. This can be readily observed by reading the comments section of YouTube guitar repair videos... my all-time favorite example of Dunning-Kruger at work is linked below.. Despite significant damage to the bridge patch during removal, destruction of the drop-in style faux through saddle, and other mayhem committed on the subject D-28, the comments are almost universally glowing in nature… but not all .

In summary, if we all could channel our inner Dirty Harry (the 1973 version), we would likely see far less carnage committed in the name of luthierie.

"A man's got to know his limitations."
- H. Callahan Magnum Force

https://youtu.be/Hd63jVYTnGA

Thank the mighty surveillance algorithms for that. Immediately after reading your post, that vid came up in my YouTube suggestions…

On the specific topic of a critique of the linked video, I would suggest reading the comment section and specifically those posted about 4 months ago by MDLuthier. Most of the issues I have with the video are covered in that comment.

Perhaps MDLuthier is a luthier from Maryland - hmmmmmmm

Perhaps MDLuthier is a luthier from Maryland - hmmmmmmm

Edit: Finally found the MDLuthier comment - wayyy down there. Comments were spot on. The first thing that got me in the video was making like it's a big deal to reglue a bridge - seriously? It just went downhill from there.

Indeed, it's his YT handle. No real surprise it's spot on.