Fret Levelling

[j. pierce]

Okay, before I plan on doing anything, I plan on reading up on all the relevant info in my books, and spending more time reading here as well; but in the meantime I'm wondering if anyone can help me out here. (I have to spend a good time reading up everytime I do fret work because it's always so long inbetween.)

Anyway, I have a recently-fretted neck on a guitar I'm building, and I'm preparing to level it. The board was flat prior to fretting, (or so I thought - now I'm doubting that) and I checked it out with a long straight edge here just to see how things looked. At first it seemed that the frets lowered a bit towards the higher frets. I explained this away because I had to hammer rather than press many of those, and I might have been a bit heavy handed. I figured no problem with things getting a little lower towards the high end anyways, that's how my main guitar is now, and these certainly weren't dropping so far that I couldn't level them out.

But on closer inspection, I realized, it's almost more like a "hump" in the middle of the neck - the lower frets also drop off a bit, and with a straightedge the length of the neck, I can of rock it. It's a back bow, and looking at it again, it's kind of a bad case of it, too.

Now, I've got a double-action trussrod from LMI in there, and I hadn't put any tension on it, so I tried tensioning it backwards. That gets rid of this neck bow.

Prior to checking it out with a long edge, I was using a little fret rocker thing, and fret-to-fret the height seems mostly dead on, a couple of high ones, but in general nothing to sweat about.

But tensioning the rod - should I do that? Reverse-tension the neck to get it as flat as I can and then level the frets? Is that a good idea?

If that's a good idea, is this supposed to really happen, though? I mean, am I trying to work with a neck that's screwed up to begin with? I thought my neck should be pretty much dead flat w/o truss rod tension before I put the strings on.

Could putting the frets in have made my neck back bow like this? I'm more assuming I was off when I decided it was flat before, (god knows I've been wrong plenty of other times) but is it possible for me to be correct and the neck *was* flat and fretting it made it back bow? (The frets did go in pretty tight, I guess) If so, is that a real bad sign for the stability of my neck? Should I have put a bit of tension on the trussrod before I fretted it?

Also, should I get this thing so I can string it up (still need to cut the nut) and do that before I do anything, and then see how things look under string tension and where the rod needs to be when it's strung?

Sorry for all the questions, thanks for any help. I'm still searching the archives, sorry it this is redundant.

[Devon Headen]

What size kerf does the blade you used to slot the board cut, and how does it relate to the fret tang? My guess is that you just got some compression and next time either need to use a bigger blade, different fretwire, or trim the tang size of the fretwire you're using now. I would adjust the neck so it reads as flat as you can get is, then level.

[Scott Rosenberger]

youve got a compression bend in the neck. It's from the slots not being wide enough for the fretwire. depending on how bad it is you may need to pull the frets and re-do the job. See if you can get the neck straight with the truss rod. If you cant it would be wise to redo the frets

[j. pierce]

The board is a pre-slotted one from LMI, so the slots should be 0.023". It's a cocobolo board. The fretwire tang width is supposed to be .020", .037" with the barbs. Think this caused the compression?

Thanks for the help, guys.

Edited January 14, 2006 by j. pierce

[Mattia]

The board is a pre-slotted one from LMI, so the slots should be 0.023". It's a cocobolo board. The fretwire tang width is supposed to be .020", .037" with the barbs. Think this caused the compression?

Thanks for the help, guys.

Did you actually measure the slots to check? Also, in ebony, even that much can cause compression, because the wood's so darn hard. Less of an issue with EIR, even less with Maple.

With hammering, well, if you're doing more than tapping them in with moderate force, they're not going in easily enough.

[erikbojerik]

Yeah its compression from inserting the frets; I've used the same slot width and fret tang, and I always get a little bit of this bow in the fretboard. It usually disappears when I glue the board to the neck....but one time it did not. A little tweek of the rod was all it needed.

When you get it strung up, you'll need to adjust the rod again. But for now, tweek the rod until you get it flat, then go & level the frets.

[ryanb]

+1, compression from the fretting. You didn't say how much backbow you actually have, but a little is not such a bad thing. The string force will pull it back forward again. As long as the string pull is enough (or more than enough) to pull the neck straight again (or into a little relief) with a truss rod adjustment, you shouldn't have to refret. The double-action rod helps this too. Use the rod now to straighten the neck as much as possible before you level the frets. Then readjust the rod as necessary after you have strung it up and let it sit awhile.

[j. pierce]

Thanks guys.

Yeah, the board is Cocobolo, which after working with, I'm assuming is hard like ebony? At least, it seems that way, particularly compared to the rosewood I was working with.

And yeah, I learned a *lot* about hammering frets in these builds. Better luck next time, I suppose.

I guess I'm going to proceed with things since I can flatten stuff out with the trussrod. If I have to do a refret, so be it, but I figure if that is the case this a free shot at practicing leveling out the frets.

Thanks again, folks.

[Mattia]

Cocobolo's one of the hardest/heaviest true rosewoods, but it's still not quite ebony. That's a good bit harder still. Indian rosewood is probably one of the softest rosewoods you'll ever work with.

[j. pierce]

Erikbojerik -

I take it from your post that you fret the board and then glue it to the neck - I'm debating doing this on my next build. I have to ask - how far along in the fretting process do you go before you glue the board? Do you level the frets? Get all the way to the fret dressing? Just attach them and trim the ends? Do you use any sort of measure to counter-act any slippage during gluing of the board? (I usually use small pins through the fret slots - I don't think that would work very well with the frets already there?) And what do you use to clamp a board down that's already got frets in it?

Mattia - Yeah, the last board I worked with was indian rosewood. That's what I'm comparing the cocobolo to, I guess. I have worked with very little ebony, and I don't really have anything to judge "hardness" by other than my subjective experience in working the various woods, which isn't really a good indicator. (Especially given the length of time between working the various pieces.) Thanks for info.

Anyone got any experience with those "fret barber" things? I've got a handheld tang compressor, but the added accuracy of those things seems worth it to me. I don't know. Seems easier to squish the tang rather than try and widen the slot.

Edited January 16, 2006 by j. pierce

[erikbojerik]

I've done it both ways (fretting before and after gluing the board on the neck). I use an arbor press to press the frets in so for me it is a little easier to handle just the board instead of the whole neck.

I don't do any levelling or dressing until the board is glued onto the neck. To prevent slippage I put a couple of staples into the neck blank and clip them so just the teeth are sticking out, they stab into the fretboard and keep it from slipping. Then I just use scrap wood or leather as clamping cauls, being careful to align the clamps so the squeeze along the edges of the board so I get a nice clean joint.