Fret leveling

[Leenhard]

Hi there,

I'm pretty new to guitar maintenance, ect. and I just started out fixing my own guitars. I had 2 questions about fret leveling:

For fret leveling, ideally you take off the neck and straight it out so it's completely flat (no relief), right? Then, you check which frets are high, mark them and file them down, etc.

Now, I have a few questions about this process: 

1) It seems more logic to me to measure high frets when the neck is still on and you have the desired relief? Because the relief will have an impact on the relative fret heights? When you first take the neck off and completely straight it out, you will have different 'high' frets then measuring it with relief in the neck. So when you put the neck back on and put some relief in it, you might not have the desired result? Or am I overthinking? 

2) They always say "you can only turn the truss rod slightly or you can damage your guitar". But when fret leveling, you take the neck off and straight it out, which in my case could take 2 or 3 whole turns on the truss rod.. So how does this comply with the statement above.. ? 
When you're done fret leveling, you put the neck back on and again turn the truss rod to the desired relief. I can't imagine luthiers turning the truss rods just slightly and leave it settling for a day,.. for each customer guitar while they are working on it??

Please help, as I'm breaking my head about it. Thank you!!

[Bizman62]

Welcome to the forum!

Your basic idea is right, that's the common way to level the frets.

1) You're overthinking. When you level the frets on a dead straight neck you could basically leave the neck straight after restringing and just raise the bridge so the strings won't buzz. However, strings move simultaneously in several patterns, the most significant after the skipping rope pattern being an eight pattern which requires some space over the lower frets as well as over the pickups. That's why some relief can help keeping the action low. Also note that putting relief in a leveled fretboard there won't be any high frets in between unless there's something seriously wrong with your neck break angle.

2) The statement applies most to a stringed guitar. When turning the truss rod with strings on you should always lower the tuning first. With strings off there's no such counteracting force so you can turn the truss rod more freely. However bear in mind that the rod may be stuck either by glue or friction so let the neck settle a while before attacking the frets. Otherwise the straight neck may warp during the leveling process, ruining your job. Tapping the neck may tell you if the rod is stuck. A rattling rod is loose and even if the neck is straight tightening the rod just beyond rattling is recommendable.

And yes, a good luthier may let the customer's guitar settle even for a week or more!

[Leenhard]

@Bizman62 Wow thanks for your quick reply! 

1) All right that makes a lot more sense now! And indeed, when you have a leveled fretboard with a bit of relief, it will be concave all the way so the first and last fret will be the highest ones. Great!

2) Okay, I was afraid I was damaging the neck by turning the truss rod freely . Worst thing that can happen when turning the truss rod too much on a stringed guitar will probably be the strings breaking or the bridge snapping off,.. ?  

[Bizman62]

40 minutes ago, Leenhard said:

Worst thing that can happen when turning the truss rod too much on a stringed guitar will probably be the strings breaking or the bridge snapping off,.. ?

Nope. The worst thing would be snapping the truss rod right behind the nut. As skinny teenager I once snapped the 8 mm bicycle saddle bolt with a wrench. Steel isn't as strong as you might think!