I suspect I may have tried to put strings on a guitar that are too light. I am wondering if there is anything that can be reasonably done to make it work?

I found a nice basic Yamaha 370 short scale dreadnaught at a second-hand store for cheap. The neck looked properly straight and even ( but with no strings) so I bought it.

On a whim, I bought a set of .010-.047 extra light D'Addarios and slapped em on. It's pretty fun! I am really enjoying these loose bendy strings on an acoustic. I've never tried it before and I like it. The problem is about a month after stringing it up, the fret buzz went crazy mostly on the 2nd fret. I wasn't entirely surprised by this as I expected the neck to react after having had no strings on it for who knows how long? I backed off the truss rod over a couple of days and it helped a bit, but I think I have hit the point of no more relief to be had in the neck. Slightly nudging forward with my fret hand fixes it straight away.
Also, I live in a very dry climate and I normally store my guitars on neck hangers... if that means anything.

Any wise thoughts or clever tricks? I'd like to make it work but it just might not be possible.
This guitar ships with a pretty light set from Yamaha;.012 -.052 I believe. Would a slightly taller bridge make any sense to try? I feel I could very slightly change the geometry with a different nut and/or bridge but I know there isn't a lot to be done if the neck won't bend enough.

Thanks in advance!

Have you put a straight-edge down the neck to check what the relief actually is now?

Yes, it’s certainly possible for the neck to straighten out under lower tension, over time and with temperature and humidity changes doing their bit as well. If the truss rod is single action, then once the nut goes slack, then you can’t add any more neck relief back in. If it’s a double action truss rod (quite common these days), then after a dead spot in the middle of the nut’s travel where it feels loose and nothing happens, it starts to bite again and you can then add in more relief.

But what you may have is a slightly high fret, which because of the small amount of relief is making its presence known. Or maybe it’s become slightly loose and popped up a bit. Ideally you’d remove the strings, then use a notched straight edge to help adjust the truss rod so the neck was as flat as possible, then use a fret rocker to see how level the frets are.

If there are any high frets, then you can first try knocking them in harder. Use a hammer with a brass or hard plastic face to it, or else put a block of wood on top and use a normal hammer (to stop the hammer deforming the fret). If this doesn’t improve things, then you can file the fret lower, then reprofile and polish it, or if several frets are high, it’s often easier to do a complete fret level.

If the frets seem OK, then it is pretty much the lack of neck relief, and heavier strings should hopefully cure it.

Are you oiling the fretboard regularly to stop it drying out?

blinddrew wrote:Have you put a straight-edge down the neck to check what the relief actually is now?

I've not! But I just did... it's looking pretty flat from the first fret to the 12th. Then there is maybe a 16th. I don't have any feeler gauges. Heh, maybe there is nothing more to be had.

edit to add :- Wonks obviously types faster than me so forgive me for repeating some of what he said.

String tension will pull the neck forward and pull the top upwards, normally the neck will have been planed flat and/or the frets levelled flat with the truss rod fully relaxed so that even very light strings will generate a little 'relief' (and raise the action slightly). As Drew says relax the string tension and truss rod and use a straight edge to see where you are starting from WRT the straightness of the neck. If it is perfectly straight then you should be starting from a good position so re-tension the strings and take the slack out of the truss rod, over the next few days adjust until you have a little relief in the neck. But, the likelihood is that you have some high frets which need addressing but that's a luthier job unless you are either fairly confident with the files or the guitar is of little value (so is a good instrument to learn on). OTOH it may be that the frets are close but not perfect in which case a shim under the bridge saddle may just get you to a playable setup without expense or major work.

blinddrew wrote:Have you put a straight-edge down the neck to check what the relief actually is now?

Do this first. You need to confirm back-bow and have an idea of how much.

After following Wonks' excellent advice you still have a high spot that is a back bow, it is possible to remove remove it, but you need to know what you are doing. However, with a bargain purchase it is sometimes worth a try.

Totally slacken the truss rod, ideally removing the nut/adjuster (it also gives you the opportunity to give it a clean and get some fresh oil on the thread so it works smoother when you re-assemble).

You need a good flat surface, a couple of good clamps and a spacer 3 or 4 mm thick. Lay the guitar fretboard down on the flat surface with the spacer between the fretboard and the flat surface beside the 7th fret. Then clamp at the nut and heel, taking care to apply clamping pressure slowly. Sight from the nut towards the heel regularly as you tighten up until you see a slight forward bow. Leave it overnight to settle.

With luck, when you release the clamps the following day the forward bow will have set. If it returns to a back bow, it is worth going through the same process again but using a hairdryer to gently heat the length of the neck. Not so hot as to damage the finish, but getting enough heat into the neck so it is quite warm but not really hot. Then leave to settle over night again.

Words of warning. If you don't feel confident working like this, don't do it. A decent guitar tech should be able to do this for you. If you do go ahead, take care when clamping to avoid putting a twist in the neck.

Finally, raising the saddle might remove the buzz, but it will mess up the action increasingly beyond the 2nd fret and the guitar will intonate increasingly sharp. Solve the problem, not the symptoms.

Let me know if you have further questions.

Andy :beamup:

If the frets are level, you really don’t need a lot of relief at all.

1/16” is about 1.5mm, which is a lot of relief in my book. So it’s probably less than that.

It’s easy to talk about, but when dealing with very small adjustments on a neck, it’s hard to know the exact cause and possible remedies without having it in front of you.

Otherwise I’d fit a set of 12s, and then give it a day or two to settle and then see how things stand.

Assuming that the frets are all good and you haven't got a high fret and the truss rod isn't dual action.

1 Take it to an experienced Luthier who will do some magic on it and sort it out. (Recommended)

2 Tune it up a bit tighter and try leaving it somewhere with a bit if humidity for a while and let nature and pressure put a little relief back in for you. Given the thinner strings maybe take it up no more than a tone else you'll probably break one. Getting a humid environment might be a bit of challenge in a dry climate - perhaps someone might have an idea about this.
(I don't think this will cause too much damage, but I'm not an experienced luthier - see point 1)

See Andy's post re what an experienced Luthier would do... :D

Wonks wrote:If it’s a double action truss rod (quite common these days), then after a dead spot in the middle of the nut’s travel where it feels loose and nothing happens, it starts to bite again and you can then add in more relief.

I've never seen that... but I've not mucked around with a guitar this way in a long while.

Wonks wrote:If the frets seem OK, then it is pretty much the lack of neck relief, and heavier strings should hopefully cure it.

So yes I think I'll have to go up to the factory spec strings. The neck is pretty much flat now. This Yamaha is the basic student model but I like the way it plays. I also see no fret wear so like many student guitars, it was never played. I'll be fixing that!

Wonks wrote:IAre you oiling the fretboard regularly to stop it drying out?

BUSTED!! I should be doing that... particularly where I live.

Jadoube wrote:The neck is pretty much flat now. This Yamaha is the basic student model but I like the way it plays.

But is the neck flat with the strings slack and the truss rod relaxed?

Murray B wrote:Assuming that the frets are all good and you haven't got a high fret and the truss rod isn't dual action.

1 Take it to an experienced Luthier who will do some magic on it and sort it out. (Recommended)

2 Tune it up a bit tighter and try leaving it somewhere with a bit if humidity for a while and let nature and pressure put a little relief back in for you. Given the thinner strings maybe take it up no more than a tone else you'll probably break one. Getting a humid environment might be a bit of challenge in a dry climate - perhaps someone might have an idea about this.
(I don't think this will cause too much damage, but I'm not an experienced luthier - see point 1)

Thanks Murray B. I was wondering if something like this might be worth a go. When I first strung it up it was perfect... which makes me think I can get back to that somehow. Its a a $40 CDN guitar so I don't think its worth spending too much on... although can you put a price on feel? It is very fun to play when it's' working.

Sam Spoons wrote:

Jadoube wrote:The neck is pretty much flat now. This Yamaha is the basic student model but I like the way it plays.

But is the neck flat with the strings slack and the truss rod relaxed?

I've not checked that yet. It is likely bow back now.

As an aside... does anyone string their acoustics with extra light strings?
I recall some session guys used to do a thing called Nashville tuning where they would string E B G with normal stings and then D A E with the light strings from a 12 string set. I never thought about what that would do to the neck...

Wonks wrote:If the frets are level, you really don’t need a lot of relief at all.

1/16” is about 1.5mm, which is a lot of relief in my book. So it’s probably less than that.

It’s easy to talk about, but when dealing with very small adjustments on a neck, it’s hard to know the exact cause and possible remedies without having it in front of you.

Otherwise I’d fit a set of 12s, and then give it a day or two to settle and then see how things stand.

yeah... I am definitely just eyeballing it at this point. I was very surprised at the drastic fret buzz that ensued. I didn't really expect that. I'll try tunning up a semitone and see if it settles itself a bit.