My neck is bowed. No truss. What can I do

[mandotrev]

I was looking online to find out how to tell if your neck isn't straight. The neck on my new mandolin looks straight enough to the eye, but when I stretch a ruler from the first fret to the the end of the fretboard, I can see that beginning on the 3rd fret and ending on the 11th that the ruler doesn't go all the way down to the frets. It is not off by much. The worst is the 8th fret which is about .75 of a millimeter off.

I am still trying to figure out the intonation problems with this thing. No truss. is .75mm enough to effect the intonation. What should I do?

[Rolfe]

If .75mm is what you are getting with string tension, and you have a nice low action without buzzes, then just enjoy it. Otherwise, leveling the frets and recrowning them should do the trick.

[Big Joe]

That is what is called "relief" and is built in so you can actually play your mandolin. Most builders who do not use an adjustable truss rod built a certain amount of relief into the neck. Only you can determine if it is the right amount for you. .75 of a millimeter does not sound like a lot of relief, so it should not be a problem. If it is, it can be fixed as Rolfe indicated. If it were way too much to be taken care of by a fret level, then a plane and refret would likely resolve the issue, but I doubt that is needed.

[Dick Hutchings]

.75 mm ~ .030". That's way too much relief.

[JEStanek]

Does it hurt to play in second position? Does the instrument intonate OK there? If so, no problemo. If not, Rolfe has the answer.

Jamie

[Mario Proulx]

Agree that if it is indeed .75mm(.030") that is way too much relief. That's more relief than I run my action at!

I suspect we're not measuring accurately here. Are we using feeler gauges or other accurate methods?

[mandotrev]

Using a ruler stretched across the frets. Sorry, Mario, amateur hour over here at the cafe. It's what I got. It's a 60 year old levin and I still need to sand the bridge which is too high.


Agree that if it is indeed .75mm(.030") that is way too much relief. That's more relief than I run my action at!

I suspect we're not measuring accurately here. Are we using feeler gauges or other accurate methods?

[pops1]

instead of pulling the frets, planing the board and refreting, another opiton would be to pull and reglue the fretboard.

[Rob Gerety]

First make sure its actually got too much relief. Then fix it if the instrument is worth fixing.

Man, mandotrev, it sounds like you are having a bad string of luck with mandolins.

[Paul Hostetter]

instead of pulling the frets, planing the board and refreting, another opiton would be to pull and reglue the fretboard.

Not a good idea for a number of reasons.

The best straightedge is to press the string (under tension) down where the barrel of the neck begins and either at the nut or the 1st fret, then measure the gap between the string and the top of a fret about halfway between with a feeler gauge.

http://www.lutherie.net/neck.relief.check.jpg

[Michael Lewis]

If you DO take the fingerboard off it would be a good opportunity to install some reinforcement. I'm not suggesting you do that but if the board is off why not take advantage of the opportunity?

[Mario Proulx]

Using the string as a straight edge, try slipping a business card between the string and the frets. If you can slip the business card in anywhere along the length of the neck, you've got too much relief. A business card is .010" to .013", and that's already too much relief.

If pulling the fretboard(not a big deal), I'd do as Michael suggests and add some reinforcement while you're at it.