Neck Buckling

[juggernaught]

OK, so I've been taking my '90 Distillate into a very good bass tech in abq, and he was going to help me get the action really low.  In the process he discovered that some of the frets around the 18th fret are doing a bit of a wave motion lowering a rising to a high point where my stings buzz when the action is low.  He claims that this is where the neck is buckling a little due to the tension.  Has anyone had this happen?  What did you do to fix this if anything?  I'm pretty sure this isn't a fret height issue, since all the frets appear to be OK.
 
(Message edited by juggernaught on March 28, 2008)

[jorge_s]

Hey Juggernaught:  What do you mean by the pickups at the 18th fret?  Do you mean the fretboard itself rises and lowers?  Or do you mean that the magnetic pull from the pickups is causing your buzz?  I very much doubt that the whole neck is buckling due to tension.  Normally the neck bows due to string tension.  If this is the case then there are things that can be done for that; primarily adjusting the truss rod.
   
If the problem is specifically and only at the 18th fret, it is definitely a fret height issue.  Have you really checked out if your frets are level?  It should be done with a good straightedge resting on the fretboard while looking against a bright light. This will reveal any inconsistencies.  Also, there should be no rocking back and fourth with the straightedge.  If it rocks at any spot then that is your high spot.  Past the 15th fret there usually is a fall off.  This is an area where the frets no longer form a straight line but get progressively shorter towards the pickups.  This is done to allow for string vibration and a lower action.  
 
In order for a fretted instrument to be playable all the frets need to be leveled; ideally with tension on the neck.  Even if the neck has small humps they can be compensated for by a fret job.
Keep in mind that if you are after extremely low action you will need to keep adjusting the truss rod a lot more often.  Just a little change in the weather will bring about buzzing.
 
If the humps are bigger that the height of the frets then the neck will have to be trued.  This is a more complicated procedure where the frets are removed, all humps sanded true with the chosen neck radius, and then frets replaced.
I hope this helps a little.   Jorge

[juggernaught]

Woops, I meant frets, not pickups.  Really this was all happening when the guitar tech was working on it.  He straightened out the neck as much as possible with the truss rods, but past the 15th or so, the frets take a dive (or so i gathered, i may be wrong) and then reach a high point at the 18th fret before leveling out.  With a straightedge there were both places with light and places with rocking.  Also, so i was told, the truss rods really only work from fret 3 to 15 or so.  Wherever it was, he was indicating that it was past that point.  His diagnosis was that it wasn't the frets, rather buckling in the neck was causing a hump.  A fret job was being considered a band-aid fix, and sanding down the fretboard was the real fix.
-devon

[David Houck]

The neck is buckleing, or the fretboard?

[juggernaught]

I'm not totally sure, but i think he said it was the neck.  It's seriously keeping from having a nice low action.

[mica]

If the fret height isn't an issue, then there shouldn't be a buzzing problem. Since there is a buzzing problem, we've got to look at the height of the frets. It's not that uncommon for the frets  to need some attention after 18 years.  
 
If the frets are not seated well from what you're describing as the fingerboard buckling (or for any reason), they should be replaced. The frets are originally glued and pressed in place, so they shouldn't wiggle. I would imagine that buckling would push the fret up out of its slot. Even a little push would show up.  
 
If the frets are seated well, and feel firmly in place, then I'd probably just do a fret mill for now. You can think of it as a band-aid or think of it as getting the most life out of your frets, and also getting the most life out of your fingerboard. A fretmill is less expensive than a level and refret. Your repairman will get more business from you overall since you'll need the frets replaced someday.  
 
Someday the frets will have to be replaced. I'm fairly conservative when it comes to instrument repair, so if it were my bass, I'd only refret when it was absolutely necessary. We recently refinished a bass for a Club member, and even though the frets looked a little funky with grooves and wear, and they were pretty flat from previous fret mills, they worked perfectly fine. So we decided together to leave the frets in place until there was a playability issue. Like I said, we're pretty conservative for repairs.  
 
You can call us here at the shop if you have any other questions.

[David Houck]

Thanks Mica!!