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I carved a great feeling neck but carried away and ended up too thin. If someone were to like it like that, would it hold up structurally? It is 19mm at first fret and 22 at the 12th.

I assume this is with the fretboard.
Do you have a trussrod? How much is left under the trussrod?

if that's with the fretboard those are good numbers.
your talking 3/4 " to 7/8 "

mike

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Mike Collins

Yes, that is with the fretboard and a truss rod. Truss rod slot prob 17mm deep.
Thanks

Is your truss rod slot really 17mm? Leaving only 2mm behind it?

It is the stewmac hot rod that is 11mm deep and my fretboard is 6mm. Sits flush against fretboard. No filler strip.

The Hotrods require a deeper trussed slot than most. I used a Hotrod once on an OM style and it broke through the neck. Just wasn't enough wood over it.

Here's a Hotrod and a LMI style (Blanchard) for comparison. Neck was adjustable hence the two graphite rods to support the FB extension. Those graphite rods most likely helped the rod break through the neck.

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Steve Smith
"Music is what feelings sound like"

In that case I would be quite uncomfortable with only 2mm behind the rod…

Thanks to you both. Very disappointing. I may try it as an experiment. It feels sturdy.

It will probably crack if you put much tension on the rod. Peel the fretboard off and replace it with a single compression rod. They don't put any pressure on the back of the neck, and work better when set in a deep slot.

Consider removing the f/b and putting a couple of carbon fiber stiffeners next to the rod. I just built a neck with CF and it hardly pulls any relief at all, you probably will not have to tighten the rod. You could replace the rod with a shallower one and glue a filler strip in the bottom of the channel.

Also think about how a double acting truss rod works. As it is tightened the ends push down under the nut and at the heel, and the center of the rod pushes up against the fretboard. Assuming you have reasonable thickness at the nut you might be all right, possibly adding a back strap or some sort of volute. If its a weak neck in that area

Several years back I had a "hot rod" start to break through. If I remember correctly, there was about 0.095" "meat" between it and the back of the neck. I removed the fretboard, made a Gibson style rod, filled in the bottom of the channel a little and steamed/pushed the "pushed out" part back to normal. Not too bad, if it's a bolt on type neck.

Compared to necks, truss rods are cheap, says me. Save the neck. Swap out the rod for a shallower one and stick a strip of unidirectional CF and a filler strip in the channnel, seeing as the channel is already cut?

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Peter Havriluk

Lot’s of good ideas here. I should qualify that since all my guitars are sold before they’re built, I’m extremely risk averse. If you like the neck, and have the ability to put in a less deep truss rod, you might have a save…

In the neck I showed I just pulled the Hot Rod, repaired the break-through then put a maple spacer in the bottom of the slot and installed the Blanchard type rod. That was about 15 years ago and the neck is still just fine.

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Steve Smith
"Music is what feelings sound like"

Thanks for all the advise. Looks like i will be removing a fretboard, but glad it is not firewood. I did engage the truss rod and turned it pretty tight with no impact to the neck, but i guess you never know what could happen over time.

It also depends on the guitars purpose. If you’re keeping it, then really there’s no harm in just finding out what happens. If you’re selling it, that’s different. I tend to look through the lense of a seller…

I've used some Hot Rods in banjo necks with good luck--banjo necks tend to be a bit thicker than guitar necks overall, but since they're so much narrower it makes sense. I did try one Hot Rod in a guitar neck that failed. Fortunately, while the neck was still under construction. There just wasn't enough meat left under the rod to handle the stress, and I was testing the whole arrangement when it happened. I trashed the neck and built another.

No doubt a single action rod leaves a lot more wood and is not likely to break through, but I still like having double action rods. The Martin style rods are nice. They offer a lot of range of adjustment, but still leave enough meat on the underside to hopefully prevent breakthrough.

Dave

+1 on the Martin style dual-action rods. That’s all I use now.


Steve

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Steve Smith
"Music is what feelings sound like"