Play the guitar. Is there excessive buzzing? Is it too easy to play or do you need hydraulic assisted fingers? String height is determined by several factors. Nut height, saddle height, neck curvature and neck angle all make one guitar’s action better or worse than another’s. String height can be changed to suit any playing style. My opinion of ideal string height for a steel string guitar (measured from the top of the fret to the bottom of the string at the 12th fret) is 1 / 16″ at the high E gradually increasing to 3/32″ at the low E.
If the instrument of choice feels hard to play, sight down the neck. If the neck looks like the cross-section of a dinner plate, then the neck should be straightened with a heated neck press.
String height at the nut can be checked by pressing down on a string in front of the second fret. There should be clearance of about the thickness of a piece of paper between the bottom of the string and the top of the fret. Too much clearance translates into a guitar that is hard to play. No clearance means the string will buzz when played open. If you have checked these things and the string height is still too high, look at the saddle (the bone or synthetic piece on the bridge that the strings go over). If the saddle is tall, more than 1 / 16″ higher than the bridge, it can be lowered. If it is close to the top of the bridge then a neck reset might be in order. A neck reset entails removing the neck from the body and changing the angle where the neck attaches to the body.
The gauge of strings can make a difference in action. Light gauge strings are easier to fret than medium or heavy strings. Check the frets. Frets wear out when strings are pressed down on them. The worn area is lower than the fret in front of it and causes the string to buzz. Loose or uneven frets are another source of string buzzes.
It is important to check for cracks, glue joint separations and loose binding. These troubles will only get worse with time. Cracks are always easier (read less costly) to repair when they are fresh. Dirt and instrument polish work their way into cracks and make the repair job harder. I have known people who refused to have crack work done because they had the mistaken notion that it might hurt the sound of their beloved instrument. Cracks will get worse over time. l have seen instruments deteriorate to an unusable condition because of neglect.
A lifting bridge is another problem that when corrected early can save you from big repair bills. Look at the edge of the bridge farthest away from the neck. A gap between the top of the guitar and the bottom of the bridge tells you that the bridge should be removed, old glue and finish scraped off the gluing surface, and the bridge reglued.
Be sure to check the interior construction. You may not be able to detect a loose brace or even a missing brace, but a glance through the sound hole may reveal something obviously wrong like gobs of auto body putty. Some bad repair jobs are nearly impossible to correct. Sometimes the most obvious things pass us by. Look at the hardware and make sure it is all there. Screws from tuners can work themselves loose and fall out.
If the guitar you are gazing at and longing for is in good condition and only needs some adjustment, don’t buy it just yet. Find out what the guitar and its problems are going to cost. I strongly recommend that before you purchase an older, used guitar, you take it to a professional repair person. Most of the time estimates are free and you can get a good idea of any problems that could cause a nightmare of future repair bills.
Keep these points in mind when buying a used guitar and you can count on years of enjoyable playing with your purchase.
Bob Smakula has been a fretted instrument builder, repairman, and dealer for 16 years. He is an active old-time musician as well, playing fiddle in the Able Brothers and Stand Bayou bands. Formerly from Cleveland, Ohio, he now lives in Elkins, West Virginia, where he operates his business, Smakula Fretted Instruments
Contact Bob at firstname.lastname@example.org