double truss trouble

[BobsterMan]

Here's something that's bugging me...

I had my F212XL into a local , seemly competent, shop, for a lifting bridge and it came back not too hot on the action, so I backed off the string tension and give the bass rod a little poke, but no improvement. A little more, and a small crack appeared in the back of the neck at the nut, right where the truss nut would now be. Bummer.

I took it to another guy, who I trusted as honest and competent, and he figured the mount had collapsed. So did I. He lifted the board, and it proved to be true, but there were six little aluminum washes in there, we figured from he previous "repair". So he built an epoxy mount, and at my suggestion, drilled the ends of the crack to reduce the possibility of its lengthening. All was well, and it played great. But in about a month, the truss rod seemed to give way, and the action got really bad. Before I take it back to the second guy (he likes structural guitar work, and my parked 80 Cutlass with a 403 (thrown rod), TH350, and an IROC 373 posi rear end... so he might deal) any ideas here?? Nobody in my city ids' themselves as an authorized Guild repair shop, if that matters.

 

[Scratch]

If you're anywhere near SC Texas, I know just the guy...

 

[BobsterMan]

dang... I am north of North Dakota...

 

[Scratch]

Man, you're waaaaay up there in North Texas! :shock:

 

[chazmo]

Here's something that's bugging me...

I had my F212XL into a local , seemly competent, shop, for a lifting bridge and it came back not too hot on the action, so I backed off the string tension and give the bass rod a little poke, but no improvement. A little more, and a small crack appeared in the back of the neck at the nut, right where the truss nut would now be. Bummer.

I took it to another guy, who I trusted as honest and competent, and he figured the mount had collapsed. So did I. He lifted the board, and it proved to be true, but there were six little aluminum washes in there, we figured from he previous "repair". So he built an epoxy mount, and at my suggestion, drilled the ends of the crack to reduce the possibility of its lengthening. All was well, and it played great. But in about a month, the truss rod seemed to give way, and the action got really bad. Before I take it back to the second guy (he likes structural guitar work, and my parked 80 Cutlass with a 403 (thrown rod), TH350, and an IROC 373 posi rear end... so he might deal) any ideas here?? Nobody in my city ids' themselves as an authorized Guild repair shop, if that matters.

Bobsterman, I'm having trouble understanding a few things... When you say "poke" do you mean turning the truss rod with a wrench? In any case, it's surely possible that after gluing a bridge back down, the guitar would need to be set up again. I'm guessing that the truss rods had been adjusted to compensate somewhat for the unglued bridge, so things would have to be re-adjusted once the bridge was glued back down.

What do you mean by the "mount" here. Are the washers that you're talking about visible at the headstock-end of the truss rods (where you tighten/loosen them)? I'm a little confused on that point. When you say the luthier used epoxy, I'm having trouble visualizing that.

Anyway, the reason I'm asking is that other folks have experienced long cracks down the back of the neck due to the truss rods. It looks like a bad capo scrape. Everyone here that's spoken about it says they're harmless and once your neck is where you want it, you can fill the crack and repair the finish (if you like).

Keep us posted.

 

[danerectal]

dang... I am north of North Dakota...

I'm south of north of North Dakota and there's an awesome luthier at Marguerite's Music in Moorhead, MN. I don't know how far north you are, but I've observed some of Paul's work there and it's very well done.

 

[BobsterMan]

Chasmo,

"poke" is unclear vernacular... yes i would say about 3/4 turn with a 1/4 inch thin-wall socket

yes, in the first repair... so things would have to be re-adjusted once the bridge was glued back down.


Well, I'm thinking that the nut on the head end of the truss rod has to apply pressure on something, when you turn the nut clockwise... and that i am calling that the "mount". If you had a good look down the inside of the neck after removing the truss rod cover plate, yes, you should be able to see the washers, which have a larger diameter than the nut, between the nut and the "mount". When the mount loses its integrity, the nut, when tightened, may travel down the truss rod, taking what it can, and force into the truss rod chamber, and split the neck from within.

It was decided to restore the strength and size of the crushed mount with epoxy.

The crack is only a couple of inches long, and the neck protruded outward slightly.

These are my deductions based on my observations and discussions with the second luthier. I suggested that he take pictures on the repair, and he did. I am sure that he wants an opportunity for a warranty repair (and my Oldsmobile) but first I need to do this discussion.

I could be all messed up in my understanding of this... anybody got a url for a drawing of a guitar..?

 

[BobsterMan]

here is a diagram...

The nut pulls on the truss rod, "convexing" the neck, through force on the "mount"

 

[Graham]

... anybody got a drawing of a guitar..?

Hope this helps.

 

[chazmo]

Hahahaha, nice Graham!

OK, well Bobsterman, keep us posted. I think you should take it back to your friend. However, if the determination is that you need a neck reset, be forewarned that that's a pretty tricky deal on a Guild.

 

[BobsterMan]

G... kind of sketchy for an engineering drawing... are you in marketing?

C... thanks, pal, that's probably what I will do... he's probably the only luthier with an old teenage crush on 80's Oldsmobile four-doors, anyway.