High E Popping out of the Nut

[mbruno]

Hey all,

I recently got a new mandolin (~August 2018) but for a variety of reasons, I wasn't using it as my primary mandolin for a while. This month I started using it as the primary and it sounds great - but on two different gigs the inner high E string has popped out of the nut while I'm playing which means I have to avoid playing the high E until I have a minute to pop the string back. Both times, it only happened once in the gig but it's not a problem I've had on nearly any other mandolin I can think of (aside from a bad quality octave I have).

I know I need to file the nut a little more to fix it - but I'm really not 100% sure about the process and I know I can screw it up if I'm not careful. With that in mind, what's the best way to fix this? I'd like to do it myself to avoid having to be without it for a few weeks etc but I'm not sure if that's a great idea.

Any thoughts?

[sunburst]

About the only thing to do is use deeper slots in the nut. Problem is, if the string height at the nut is correct now, deepening the slot will make the string too low and cause buzzing. If you're lucky and the string height is a little too high, then you can get away with deepening the slot a little. The other E will probably need to be correspondingly lowered to maintain intonation. If the string height is already good, a new nut will be needed, or perhaps a shim under the existing nut followed by re-cutting all of the slots.

The real problem may be the placement of the tuners. If the angle of the string to the tuner post is too much laterally, it can be difficult to avoid strings popping out of the nut slots. Can't really fix that, so as I said, about the only thing to do is deepen the slot.

As for how to do it, you'll need a file of a good size for the string, place it is the slot and angle it so that the slot will be filed at an angle that roughly bisects the angle of the string to the bridge and the string to the tuner post. (Ideally, that will make the slot slightly diagonal and well as sloped toward the peghead, but you probably won't be able to do that since the slot is already established.) Give it a stroke or two and hope for the best.

[EdHanrahan]

Just an outside chance: Is the string wound downward on the post from the hole, so as to provide maximum down-pull across the nut? If opposite, where the string leaves the post close to the top, that might provide little enough downforce to botch things up.

[mbruno]

About the only thing to do is use deeper slots in the nut. Problem is, if the string height at the nut is correct now, deepening the slot will make the string too low and cause buzzing. If you're lucky and the string height is a little too high, then you can get away with deepening the slot a little. The other E will probably need to be correspondingly lowered to maintain intonation. If the string height is already good, a new nut will be needed, or perhaps a shim under the existing nut followed by re-cutting all of the slots.

The real problem may be the placement of the tuners. If the angle of the string to the tuner post is too much laterally, it can be difficult to avoid strings popping out of the nut slots. Can't really fix that, so as I said, about the only thing to do is deepen the slot.

As for how to do it, you'll need a file of a good size for the string, place it is the slot and angle it so that the slot will be filed at an angle that roughly bisects the angle of the string to the bridge and the string to the tuner post. (Ideally, that will make the slot slightly diagonal and well as sloped toward the peghead, but you probably won't be able to do that since the slot is already established.) Give it a stroke or two and hope for the best.

Thanks for the insight. I'm debating contacting the luither since it's still fairly new and this seems like I could mess it up quickly. I have the files I think but just kinda nervous!

[mbruno]

Just an outside chance: Is the string wound downward on the post from the hole, so as to provide maximum down-pull across the nut? If opposite, where the string leaves the post close to the top, that might provide little enough downforce to botch things up.

The string is on the top of the tuner - so not a bad idea for a first attempted fix. Maybe (hopefully) that's enough. I may or may not have restrung after a few beers at the Great 48 haha

[Phil Goodson]

Another thought is that the nut slot may not be ramped enough downward towards the tuners.
If so, this could be fixed without changing the height of the forward edge of the nut.

[Br1ck]

Get Rob Meldrum's free e book and a set of automotive feeler gauges. Measure the distance between the strings and the first fret. If they are higher than they should be, you can deepen the nut slots.

[mbruno]

Just an outside chance: Is the string wound downward on the post from the hole, so as to provide maximum down-pull across the nut? If opposite, where the string leaves the post close to the top, that might provide little enough downforce to botch things up.

Sorry I haven't been back to post the results - but I think this was more user error than mandolin issue.

I normally wind new strings down the tuning peg but the string in question was strung up the peg (maybe I was a little intoxicated or something haha). Either way, it looked plausible that the issue was the string was sitting too high on the peg. I've restrung the mandolin completely (needed it anyway after a few gigs) and have not had the issue occur since. Looks like I'm 100% to blame for this one haha. Similar to the "when in doubt, plug it in" line in IT support haha.

Thanks for the advise everyone and thank you Ed for the commonsense I should have had earlier haha

[Tom M]

Hey mbruno glad you figured out how to solve this problem.

I was having the same issue. In fact it sounds like EXACTLY what was happening to me just prior to my mandolin head snapping clean off. The tension on the strings along with some really inferior wood was the culprit. So the head was bowing forward and the strings were able to pop out of the nut as they were rising out of the nut a bit.

(I had my instrument tuned down a whole step to begin with and I couldn't figure out why the strings wouldn't snap before the wood if the tension of the strings was too tight.)

The inferior mando I owned was an Ibanez that I paid roughly $150 for so it wasn't a great instrument to begin with, but even so . . . no excuse for the inferior quality of the wood.

Sounds like you solved your issue though. If you are confident in the luthier's skills and the quality of the materials of the instrument your all good but if it was a cheaper model I would be curious who made it and if you can have them take a look at it and make sure the neck isn't bowing.

Tom
Tom

[mbruno]

Hey Tom -

While the symptom was the same, I don't think it's the exactly the same issue. This was strictly just the string popping out. The neck is in fine shape and no evidence of any warping (for one, the strings tend to stay in tune very well and the intonation is spot on - if it warped, the strings would consistently be out of tune and/or not intotated properly).

In your case, it sounds like the strings were stronger than the weakest spot in the wood - regardless how much you spent on it, that's still pretty bad. Sorry to hear

As I'm fairly sure this was user error and not luthier error, I'm not going to provide the name of the instrument for fear I inadvertently taint their name. The mandolin is in great shape and sounds awesome. I just raised the action slightly and it's a world of difference. I'm still getting used to the new height so I'm slower than normal, but I'm really enjoying it.