Backbow Suggestions Needed

[Robbie Collins]

I just refretted a Les Paul Custom.  With the strings off, an 1/8th of a turn of the truss rod nut straightened the neck. With the strings on, only slightly more tension. Not good, but it had .009's and I would restring it with .010's so I didn't worry about it.

The ebony fingerboard was problematic...very flakey and frets didn't want to stay down. After I refretted it I put it in the case for a few days. When I pulled it out to set it up, quite a few frets had unseated themselves. So, I refretted it again.  I had to pull, crimp, and re-seat almost every fret to get them to stay down.  I superglued the frets each time. The second time I also clamped them while the CA dried.

So, yesterday I leveled and polished the frets. Today I made a bone nut and began the setup. Now the guitar buzzes over a wide area in the middle of the neck.  I played with the truss rod but and, strung to pitch with the .010's, it is straight with the TR nut almost loose.  I suppose my crimping did some neck compression.

I'm thinking I need neck relief. Obviously, I'm over-invested in this repair and would like to find the simplest method of fixing it, but I will do what ever is necessary. The options I see are

1) Tighten the TR nut, put the neck into a slight backbow, and re-level the frets.

2) Pull the frets, tighten the TR nut to create backbow, level the fingerboard, etc

3) Heat the neck until the bottom of the neck is hot, put a block at about the 6th fret, lay a square steel tube on top, clamp at the first fret and near the body, and leave overnight.

4) Same as three but pull the frets first and refret afterwards.

[Robbie Collins]

I'm trying #3. Heating to 250F until bottom of neck is hot then clamping it into a forward blow until it cools.

[Andrew]

When you installed the frets initially, did you clean the fretwire with acetone before installing and gluing them? When the wire is extruded at the factory it probably gets some kind of lubricant on it that will make the frets fight you. Since ive started cleaning my wire off before I use it Ive had less problems getting frets to stay in place. It might also be an idea to give the fretboard/slots a good clean with naphtha. If its been oiled a lot you could potentially have similar problems. Eliminate the factors that prevent frets from staying in place and you wont need to make them fit so tight, therefore less compression, less backbow. Of course now the slots will be expanded from the crimped tang, so be careful pulling the frets and take your time with the new frets, getting the fit of each just so, checking the fingerboard after each fret, etc.

Basically id go with something like 2, but be careful not to introduce too much relief by levelling the fretboard with the truss rod tensioned.

[Robbie Collins]

Thanks for the ideas, Andrew! 

I religiously clean fretwire with naptha as per Dan Erlewine's advice on his fretting DVDs.  I sometimes forget, but not this last time.

On one of Dan's videos he has a guitar with a slight backbow and he does #2. By sanding the fretboard while it is upbowed, he takes more off the middle and creates a light forward bow. I'm not sure if you understood that I've now refretted the guitar twice. Since the buzzing is spread over 3-4 frets and isn't severe, I'm going to try #1 after I've finished with #3, and save #2 for "if all else fails."

Your suggestion to use naptha in the slots is a good one. I never considered that. On the downside, this neck has a flaking problem and a cloth will surely snag on the slot sides, perhaps creating more flaking. Then again, I can't pick and choose which problems to address. If the oil is an issue then I'll just have to deal with more flaking. The slots are pretty wide and uneven in width from a prior refretting which is probably the dominant problem.

[Andrew]

I did notice youve fretted twice. Sometimes things just fight. Hopefully your chosen method works out. If the buzz isnt severe that could do the trick. Take a step back and do something else to clear your head - I like to split wood when I have to blow off steam lol. Just think how relieved youll be when youve tamed this one :).

[Paul Verticchio]

I just want to wish you good luck with this, Robbie. You've certainly had your hands full with this one.

We all have these problem children from time to time, and they're NEVER fun.

You'll get it in check eventually, and will be soooooo happy to have it leave your shop. May that day be soon :)

Good luck, buddy :)

[Robbie Collins]

Thanks, Paul...I need it.

This guitar is one of several I'm working on for a pawn shop that specializes in musical instruments and audio equipment. Every guitar I've seen has had similar or worse problems. I've come to the conclusion that many of the guitars people sell to (or fail to redeem) pawn shops are clunkers.

[Paul Verticchio]

You bet, Robbie. Even among the top-o-the-line models, (like the LPC), there are dogs. Seems like you have one that bites the mailman and barks at the moon.

Many of the vintage instruments I see nowadays in near mint condition are dogs 80% of the time. The reason they are still in good condition is that for some reason, they barked and their owners slipped them under the bed. A twisted or deformed neck tops the list quite often.

If there's a silver lining, doing work for that shop will expose you to many 'basket cases' that, once conquered, will provide you with an advanced course in skill building. Plus, you get first shot at any really great ones that come in :)

I hope your next attempt is successful :)

[Mark A. Kane]

My advice? No to 1,3, and 4. They are all half-measures and don't IMO reflect the work of a pro.. If I were the customer, or if it were my guitar, 2 is the only option. Having said that, there are varying degrees of 2. You don't want to get crazy with material removal. A combination of truing the neck under slight back-bow and some de-barbed frets will do nicely. I realize you've done the work twice, but if your standard is perfection and customer bliss, you have to start from scratch. This is how we learn ;)

Stay with it. Getting it right after all the work will be extremely satisfying.

[Robbie Collins]

Thanks for steering me in the right direction, Mark! 

I did #3 and it worked well...too well. Now, with the truss rod cranked there is excessive relief: I've gone from one extreme to the other. I'm going to try to do a slight correction first so I'm reheating it, this time for a shorter period and I will use less torque on the clamp afterwards. I was very careful and made cardboard guards faced with tinfoil to cover the binding and there was no damage whatsoever.

Afterwards, I'm going to pull the frets again and level the board :-(  A shame...I spent a lot of time cleaning up the binding and micro-meshing the neck after the last fret job.  "Once more, dear friends, into the breach."

[Robbie Collins]

Question: is slipping the neck no longer considered a professional solution (#3) or is it just a preliminary step before leveling the fingerboard? I got the idea from Kamimoto's 'Complete Guitar Repair' but I guess 1992 was quite a while ago.

[Andrew]

I think the main issue there is that the wood will want to go back to its former shape, the glue joint may be compromised, and the risks to binding and inlay. Kiln dried wood by my understanding doesnt like to be bent/otherwise coerced, so if the fingerboard joint or what have you wasnt straight to begin with, you have to shape it straight to assure it wont go back (not that this is the situation here, just trying to illustrate a little).

[Robbie Collins]

Thanks, Andrew...that's helpful. I think I may have evidence to support your point. When I put the (excessive) relief into the neck, I heated the neck for 3 hours (until bottom of neck read 150f with a infrared thermometer) and used two one-handed bar clamps with modest pressure. Because of the excessive relief I heated the neck again for 30 minutes, using one clamp with less pressure. I thought this would take about 1/6 of the relief out but the neck went back to where it began which seems to indicate the wood had memory.