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Truss rod through back of neck
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Author:  Map63 [ Wed Nov 22, 2023 12:20 am ]
Post subject:  Truss rod through back of neck

In 1982 I made my first guitar, which was a copy of the John Lennon Rickenbacker.
I used a Dimarzio Super II and an SDS1. Everything went well until I painted it.
I hung it over the rafters of the garage. When I jiggled the rope to let down the guitar, it released suddenly and snagged. That caused the guitar to bounce off the hook it was hanging from.
It bounced off the concrete floor on the bottom edge and landed on the face of the fingerboard.
Nothing seemed wrong until much later when it was completed and I was playing it.
I saw that the fingerboard had split from the neck at the glue joint.
When I re-glued the crack, I exerted too much clamping pressure on the rear of the neck and pushed in the thin wood behind the truss rod. Whenever I adjust the truss rod, it pushes out from the rear.
I am in the middle of a refurbish of this guitar and want to correct this issue.
My buddy wants me to add a new headstock with a long scarf joint from the nut to the fifth fret.
I was thinking of chiseling the wood around the break and adding some wood to add thickness.
It will have a hump, but I'm okay with that.
I read a few articles where they used carbon fiber mesh with epoxy.
Has anyone done such a repair?
I'm including a picture I found online where someone else had the same issue, when they over sanded a thin neck.
Thank you all for any help.

Author:  Hesh [ Wed Nov 22, 2023 5:45 am ]
Post subject:  Re: Truss rod through back of neck

What truss rod did you use?

We did a repair for a well known builder who had the StewMac Hot Rod truss rod come through the back of the neck where we see the bulge in the pic. Our mission was no visible hump or repair.

So I ask what truss rod because the Hot Rod is or was some years ago dimensionally deeper than others making it a bad choice for slim taper type necks. Our solution which is working and in service to this day 17 years later was to remove the fret board, remove and pitch the SM Hot Rod truss rod. We inlayed wood in the bottom of the truss rod channel. We may have flooded it with thin CA too to firm up that area and then we installed a modern, double action rod that was only 2/3rds the height of the SM rod. This put more wood in the bottom of the truss rod channel.

My memory is sketchy but we may have used aircraft quality plywood that molders use in the bottom of the truss rod channel for extra strength.

For a visible repair with hump, maybe there are lots of approaches to this including adding exterior wood.

A new neck would be one approach too that would completely remedy this with no hump or deformation for a player to feel.

Also last question Riks have two truss rods does this interpretation of a Rik also have two rods and what kind of rods did you use?


Author:  Chris Pile [ Wed Nov 22, 2023 8:36 am ]
Post subject:  Re: Truss rod through back of neck

A proper repair would be with wood - not carbon fiber. Seems the problem wasn't the guitar hitting the floor. The damage was done during construction by making the neck too thin or installing the truss rod too deeply. Even Fender has done it. Back when I was an authorized Fender repair center I did several of these where the truss rod pushed out the back of the neck. It required removal of the fingerboard and truss rod, adding new wood, rerouting the slot, etc. It was time consuming and expensive, but it worked. Good luck!

Author:  Map63 [ Wed Nov 22, 2023 12:55 pm ]
Post subject:  Re: Truss rod through back of neck

I agree. The hitting on the floor caused a crack. The "repair" caused the damage.
I made the neck too thin for the truss rod I bought from Luthier's Mercantile in 1982.
The clamping at the rear of the neck caved in the thin wood. It was my first guitar
It's a double action rod that is made of a single rod bent at the end that comes around back to the adjustment nut.
It is wrapped in shrink wrapping. It is deeper than most rods nowadays.
I will not remove the fingerboard. If I have to resort to that, I will remove the neck and make a new one or use a scarf joint to add a new head and neck at the lower frets.
My buddy did that to a broken head stock and it came out great.
He used a router on a guide to route away the rear of the neck from the nut tapering away from the fingerboard to around the third fret. (picture}.

Author:  Chris Pile [ Wed Nov 22, 2023 3:54 pm ]
Post subject:  Re: Truss rod through back of neck

Let us know how it goes!

Author:  Map63 [ Thu Nov 23, 2023 12:43 am ]
Post subject:  Re: Truss rod through back of neck

The guy who repaired the break (first pic) on the back of his neck, removed some wood next to the truss rod and glued in some wood that left a small hump on the back of the neck at the first three frets.
My buddy who routed the neck scarf joint made the headstock with some extra neck wood.
It's hard to see the repair.

I'm trying to preserve as much of the original guitar as I can, so I might opt for removing some of the surrounding wood and gluing some extra wood.
If that doesn't work out, I will do the scarf fix.
Right now, I plugged the old pickup cavities and matched the wood to the surrounding face.

Side note on routed guitar neck in pic #2.
The local Guitar Center had the guitar with the headstock missing and lost.
It was an Epiphone acoustic with a pickup.
They offered it for $10. and said "it can't be fixed" and smirked when I said "sure it can."
I gave it to my buddy for repair practice. His repair came out perfect.

Author:  Chris Pile [ Thu Nov 23, 2023 7:50 am ]
Post subject:  Re: Truss rod through back of neck

In my experience, Guitar Center staff are the least knowledgeable or capable on the subject of guitar repair. They always prove to be complete hacks. I've had to repair far too many of their mistakes - at least when it wasn't so badly done the client would pop for it.

Author:  Dave Livermore [ Thu Nov 23, 2023 1:01 pm ]
Post subject:  Re: Truss rod through back of neck

Map63 wrote:
Has anyone done such a repair?

Yes, yes I have. Similar deal. One of my first builds.
Ended up remaking the neck from scratch and am so glad I did. After building many many necks, my first ones pale in comparison.

You might consider doing the same.

It’s possible to repair, But would probably be better with a new neck.


Author:  SteveSmith [ Thu Nov 23, 2023 6:15 pm ]
Post subject:  Re: Truss rod through back of neck

I’ve also repaired one on an early build with a Hot Rod. Put in more wood in the bottom of the channel and a Blanchard rod which wasn’t as tall as the Hot Rod. Been working well for over 10 years.


Author:  phavriluk [ Mon Nov 27, 2023 11:36 pm ]
Post subject:  Re: Truss rod through back of neck

My opinion is for a new neck. Permanent fix, no workarounds. Might well be less work than repairs. Chance for a refret, too!

Author:  Map63 [ Wed Jan 17, 2024 12:17 am ]
Post subject:  Re: Truss rod through back of neck

I have thought about a whole new neck, except I built the guitar with three pieces of birdseye glued together for a thru neck.
In 1982, Luthier's Mercantile had 1"x4"x30" highly figured birdseye for $5. each.
I remember thinking that was a crazy price.

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