Frets still buzzing after levelling

[Mobilae]

Hi,

I’ve been working on my guitars for many years and have performed many fret level jobs with great results (to be clear, not profesionally). However, I’ve recently come across a Strat that just won’t stop buzzing! Here’s the story:

- This Strat had undergone a poor refret (by someone else) and was having terrible fret buzz from fret 14 and up.

- The truss rod works fine and the setup overall was allright (factory action, not ridiculously low or anything). The neck is not warped in any way.

- I removed the strings and straightened out the neck, then levelled, crowned and polished all the frets using my 24” levelling beam.

- The frets are now perfectly level over the entire length of the neck...

- And now it still buzzes terribly, but this time on the lower frets (1-6)!

I’ve always levelled frets with the strings off, but when I tension this neck by putting strings on something weird seems to happen. When I straighten out the neck with the strings on, the frets show some relief around the 15th fret. So basically this neck behaves strangely with the strings on...

I have therefore decided I will level the frets with the strings on. I purchased the Stewmac under string fretbar and will attempt to level them again. However, I’m not sure if I should do this with a straight neck or with some relief? This situation is quite new to me so I hope some of you can help me out. Maybe I should use a different approach altogether? Any other things I could check? Oh and yes, I’m sure it’s fret buzz (not something else buzzing).

Thanks!

[ScottR]

Try shimming the nut with a piece of paper or two to see if it goes away, before doing anything drastic. If you know for a fact your frets are level, buzzing on the lower frets usually indicates the nut slots are too deep.

SR

[Mobilae]

Thanks for your reply! Already tried that though... Also I know for a fact that the frets are perfectly level when the neck is not under tension. However they are NOT level when I put strings on the guitar! I’m not talking about relief created by string tension here. The neck actually becomes somewhat of a rollercoaster (of course highly exaggerated) when under tension. Hence my intention to level the frets again with the strings on.

[Bizman62]

Am I reading you right, is the neck still straight with the strings on?

If so, loosening the truss rod for some relief should do the trick. The string movement is at the largest over the 5th fret or so which requires a gap at that area. Some luthiers even carve the gap for lowest possible action.

[Mobilae]

It’s a 90’s USA Strat. No visible damage. Overall in good shape. I don’t think it has seen any abuse.

I don’t know, it just seems to behave strangely. I can’t quite put my finger on it. Could be an internal issue. It’s definitely not a nut slot issue.

I’ll try leveling  it under tension to see if that does the job.

[curtisa]

13 hours ago, norm barrows said:

That would indicate nut slots too low - as mentioned above.

Only if the OP meant that the strings buzz against the first six frets when played open, which he/she didn't actually specify.

 

16 hours ago, Mobilae said:

However they are NOT level when I put strings on the guitar! I’m not talking about relief created by string tension here. The neck actually becomes somewhat of a rollercoaster (of course highly exaggerated) when under tension. Hence my intention to level the frets again with the strings on.

S-shaped neck deformation, perhaps? Could explain why you're able to get a perfect fret leveling with the neck dead flat, but things go awry under tension with the trussrod starting to take the slack up.

Fender neck hump caused by uneven, gappy contact in the neck pocket?

[Mobilae]

Well... I fixed it! Sort of...

Leveling the frets with the neck under tension did the trick. The frets are now definitely dead flat with the strings on.

I do think there’s something weird going on with this neck. For example, I can not set it to ‘factory’ neck relief (0.010” for 9.5” radius). As soon as I reach about 0.008” relief the truss rod is already completely loose. I now have it set to 0.004” relief and I achieved an action of 4/64” on the bass side and 3/64” on the treble side with no buzz at all. I would have liked it just a little bit lower (I usually aim for 3/64” and 2/64”) but for some reason this neck just won’t allow it.

Also, I think Curtisa brought up a good point about the S shaped deformation. It might not be exactly what’s going on here, but I definitely think this neck suffers from at least some kind of deformation issue. And it seems to manifest itself significantly more when the neck is under tension. This could have been addressed during the refret, but unfortunately the person who did that did not take it into account. I have now been able to correct it somewhat with the fret level but maybe I’ll refret it properly sometime in the future.

[mistermikev]

i had a similar issue with a carvin neck thru I owned a few years back.  when not under tension you could get the frets/fretboard perfectly straight... then when under tension the first 3 frets of the neck would bow back.  It wasn't a huge change so barely perceptible to the eye, but you'd def know it by the action.  Had brought it to an expensive luthier in LA and had him put it in his 'steam box' and try all sorts of things... he ended up giving it back to me 'no charge' because he couldn't do anything with it. 

I experimented on it myself a few years later in a number of ways and I could get the thing to be perfectly straight under tension... for about a week.  then it would always just meander back to having a back bow at the first three frets.  Guitar had crazy low action but the first 3 frets were a bit 'soupy'.  I just compensated for it when it wasn't under tension and filed the frets lower everywhere else.  It played great at that point but I would bet any luthier would struggle with a fret level on that one.  Sometimes wood just does what it wants.  seems like in the end you too decided to stop fighting it and I think that's all you can do in that situation.  glad it all worked out.

[Byacey]

Perhaps you have some loose frets that are springing back up when the strings are tuned up to pitch. I've seen cases when the leveling beam holds them down, but they spring up slightly afterwards. A bit of glue in the fret slot and clamping it down can cure this issue.

[Byacey]

I should mention, a fret rocker will quickly reveal what is going on.

[JayT]

On 7/19/2020 at 10:23 PM, Byacey said:

I should mention, a fret rocker will quickly reveal what is going on.

Also - and probably a newbie comment - but be sure to check the level across the full fret radius. In other words I had same issue even after I checked & leveled but really was only checking down the center line of the neck. 

[Corsara]

Just ordered the Stewmac understring fretbar to tackle a similar problem.  Did you ever figure out if the neck should be straight or with a relief when leveling with the strings on?

[Crusader]

Well its two years later but never mind its still worth a comment. It sounds to me like the truss rod curve is wrong

[Prostheta]

It could be any number of things, and yes, bit of a zombie thread.

I would have mentioned that Fender necks are often prone to a phenomenon called an S-curve. I'm not an expert on Fender necks and I am sure that it occurs with other bolt-on designs also. Simply put, the most flexible part of a neck is within the rounded part, and it is under the most tension around the 12th fret. Above there the neck becomes stiffer and under less tension, especially where it becomes the heel. This results in an uneven curvature under string tension which is what the StewMac jig that holds the neck in playing tension without strings for levelling is intended to achieve. Whether this is exclusively an issue with certain types of truss rod, fingerboard vs. skunk stripe construction, not sure. Most people add in a bit of falloff to the upper fret area anyway; a few strokes extra after levelling.