Help with 12 String Neck

[Saransk]

I just received a '65 12-String Neck and on first looks, I saw nothing to indicate any issues
A visual check down the fretboard did not reveal any apparent bowing, either forward or back.
(I've purchased/owned several Warmoth necks with the "Modern Construction" and all have been almost perfect right out of the box  -- very little truss-rod adjustment needed when strung up.)

I'm having a real issue with this 12-string neck.  After putting it, a Warmoth hardtail Jazzmaster body, and Gotoh bridge together ans stringing it up, I have a up-bow that I cannot adjust out.  I followed the instructions - took off the strings - removed the neck - and adjusted the heel-nut to flatten the fingerboard.  Unfortunately, after  1 1/2 turns I still had some up-bow, not much, but some at the 8th - 10th frets.  But I thought even that would be okay.  Put it all back together and added strings and put tension on the neck.  Almost the same amount of up-bow and 2 turns of the side-adjustment screw made no apparent change.

MY question - is there some trick or other unique setting for a 12-string neck to begin with - do I need to crank the heel-nut down further, maybe 3 or 4 turns to start.  Could the wrong truss-rod have been put in - I know it's the same length but does a 12-string need a "stronger" model?
Or do I just have a neck with a problem.

This is my third electric 12-string and I've never had a neck that wouldn't adjust.  Hopefully I just need to reset the starting point and that will allow me to get the neck straight.

Thanks
Mike

 

[mayfly]

I'm only one data point, but I had to use a load of truss rod tension to get my 12 string neck to straighten out.

Yes 3-4 turns at the heel is a good place to start. then I applied pressure to the neck when strung up to adjust the rod further. 

 

[spe111]

I haven't used that kind of neck yet, but if you're out of adjustment do you need to add shims?

 

[AirCap]

I haven't used that kind of neck yet, but if you're out of adjustment do you need to add shims?

Shims where exactly?

 

[spe111]

Between the nut that you use to adjust the truss rod and the neck.

 

[Seamas]

How much relief are you measuring when the guitar is strung up and in tune?

 

[Saransk]

The neck uses the dual action truss-rod
It "floats" in the slot - Warmoth actually explains how it works as well as anyone - look at "Necks"

Hearing that someone else had to really "crank" the tension on the initial heel-nut adjustment makes me less concerned that I need to go back and add a couple of turns and get the fretboard really flat - more turns than I might normally start with.

Hopefully, with some more base tension, the side adjust might actually get the front-bow under control.  I'd rather not have a bad neck and have to get a replacement.

 

[Rick]

other places shims can be used are under the heel and bridge.  But I think Spe has it.

Might I recommend an excellent book:  Guitar Player's Repair Guide by Dan Erlewine.  A lot of good ideas.  Of course, not as fun as asking Q's at the Unofficial Warmoth website, but a book like this should be in everyone's library.  I'm told there are other more serious books, but this will get you started.

 

[Saransk]

The double-action truss-rod does not anchor to the neck - it basically sits in the routed slot and just pushes against the neck.
I think of its action like a steel bar inside the neck, you adjust the bar and it transfers the pressure to the neck.  But it has no anchor.

As for "relief"/action, with the #6 saddle all the way down it is about .120 at the 12th fret, more like a bass, and much higher than my Ovation 12-string.  And you can see the curve when you look down the neck from the bridge.  It's like the neck of this old KAY 12-sting I found in the 70's that I always had to tune a step down and use light strings because it always had a bow in the neck - good workout for your hand to play bar cords.

AS for books, etc. - I have several.  I posted here because I've never had a Fender, or Warmoth, neck that wouldn't flatten with it's truss-rod.  I had just finished a custom build where the neck had a couple of graphite rods put in as well - I suspect that you could use bass strings and not bend that neck.  I thought I might connect with someone who has used the '65 neck before and that there might be some "secret" got getting it started.

 

[Seamas]

As for "relief"/action, with the #6 saddle all the way down it is about .120 at the 12th fret, more like a bass, and much higher than my Ovation 12-string.  And you can see the curve when you look down the neck from the bridge. 

OK, I was asking about relief --the amount of neck curvature.
Capo the first fret, and then fret where the neck meets the body.
Then with a feeler gauge measure --at the 7th or 8th fret -the distance between the top of the fret and the bottom of the string.
You should have about .01-.012 if you are a light strummer, and between .015-.02 if you hit the strings pretty hard.
Tighten the truss rod if you are over that, loosen if under.

 

[spe111]

These bots are insane.

 

[rgand]

Yeah. They've been at it this morning.