Houston, we have a problem....

Yesterday I decided to do the final touches and set the action on the twins. I did the red one first, I set the nut height so the strings are .020" above the first fret at the low E, and .012 at the high E. That is still a touch high, but it give some room for fine tuning once the giftee gets to play it. I set the action at the 12th fret to 8/64" for the low E and 6/64" at the high E. This is a good middle of the road to high action which allows for lowering. I set the relief to .007" at the 7th fret and checked for any buzzes. Everything went well and I put it away, then got the green one to do the same thing. That is when I discovered a problem, a fairly significant problem. I got all of the settings the same as the red one, but I was having trouble with the relief. I was getting barely .002" at the high E 7th fret, but I had .012" at the low E. Something was definitely wrong. I adjusted the truss rod, and only could get the bass side to change, the treble side didn't want to bow much. I was able to get it to .004" but that was it. So I sited down the neck to see what was happening and that is when I discovered a twist in the neck. It wasn't a huge twist, but the head stock was not straight with the body, and the fingerboard had a slight twist raising the treble side. When I released the truss rod, it helped remove some of the twist, but it was still there.

I had a decision to make at this time. The guitar was very playable, and there were no buzzes. I was able to get the action where I wanted it, and I could get enough relief to let it play cleanly. The problem was if anyone looked down the neck, they would see the twist, and the head stock was twisted. The decision was to leave it alone as the person getting this guitar is a teenager and has never played before so it would be fine for them. But, if I did this, I would always know that I didn't try and fix it. The other option obviously was to try and correct the problem. I decided to give the repair a shot. I got online and learned about heat pressing the neck to help remove twists. It is a fairly successful method used and it saves having to re-fret and plane the fingerboard.

Basically, what is done is the neck is twisted in the opposite direction of the original twist, then heat is applied to the fingerboard. There are a couple of tricky parts to this job however. First, a method of holding the guitar firmly down, while a jig is used to apply the opposite twist must be figured out. The other issue is how much heat to use. The idea is to heat the glue under the fingerboard just enough to cause it to creep, but not so hot to break the bond, or to warp the neck. The idea is to get the glue to right around 140 - 160 degrees so it will creep but not heat the rest of the neck too much. After much thought, I came up with a method to hold the guitar, apply the required back twist, and then heat the neck using my bending blanket. I rigged everything up, put the heater on a couple of metal rulers sitting on the frets so the blanket wouldn't scorch the fingerboard, and clamped a wood caul over the entire setup. I fired up the blanket and let it go until I could just feel warmth on the back side of the neck, and could see the glue line along the binding creep a very small amount. Basically just enough to feel with my finger but not any more. I let the entire thing cool down over night and removed the clamping jig. I am happy to say the neck is much straighter than it was. It isn't perfect and it still has a very slight twist but it is nowhere near what it was. I leveled the frets, re-adjusted the truss rod and strung it up. The truss rod is still not moving the treble side as much as the bass side, but I think that has to do with the wood possibly being stiffer on one side than the other. I am able to get .006" of relief on the high E now, and .007" on the low E. If I adjust for any more however, it only moves the low E side. Hopefully over time, the pull of the strings will create a bit more relief so that I can back the truss rod off of it's current tight setting.

So, the guitar isn't perfect and it will most likely need a re-fret and fingerboard leveling in the future, but it is perfectly acceptable to me for this being a student guitar. It has no buzzes and it sounds great. I do need to replace the saddle as it had a hollow spot in it that showed when I was shaping it. It makes the two high strings make an odd sitar type sound. I have one more nut blank so I will probably do that tomorrow. I will watch the guitar for the next year to see how things are holding up with the neck, and if needed, I will remove the frets and level the fingerboard. But for now, I am leaving it alone as Christmas is right around the corner! I have to say, this guitar neck has been nothing but trouble from the beginning. First the truss rod channel problem requiring the cutting of the neck and adding the mahogany piece down the middle, then the neck block being crooked, and finally this neck twist. This one has been a real test!

Okay, enough of my rambling, here are some pictures:

The green guitar, just before all of the drama happened.

I picked up one of those little Mouse random orbit sanders a few weeks ago and it works great for things like this. I used it to shape the top of the nut once I had the nut slots cut to depth. It is a lot easier than using a file and sanding block.

Here is a picture I took down the neck just before I started the heat pressing. If you look closely, you can see that that treble side is higher than the bass side. The peg head is also slightly twisted in that same direction.

Here it is clamped in the jig. You can see that I had the jig pulling down on one side and pushing up on the other causing an opposite twist.

Here it is from the peg head. You can see that the fingerboard is straightened out and the peg head is slightly twisted in the opposite direction.

I put two metal rulers between the blanket and the frets, and a flat board on top. I clamped the board down with 3 bar clamps before heating it up.

This is the glue line that I spoke about. You can see that the fingerboard slid very slightly on the neck blank which helps counter the twisting. I will sand the edges smooth and re-apply tru-oil so the glue line can't be felt.

Here it is now. The fingerboard is pretty straight now. It still has a very slight twist but it isn't very noticeable, and it doesn't affect playablity. The picture is kind of deceiving as the saddle is angled and the strings have different action heights which gives the optical illusion that the neck twists. I had to remove the saddle to line my eye up with the bridge to make sure things were straight. The saddle angle and string action makes things look crooked when they really aren't. I probably should have taken the picture without strings or the saddle now that I am thinking about it!