Cf Neck Rods

[Liam M]

Hi guys,

I'm making some real progress on my project, and recently picked up some carbon fiber rods I ordered. They are rectangular in shape, being of end dimensions 9x3mm. Before I cut anything, I need some advice on how to place these things!

first off, should I lay them flat, or on end? obviously laying them on end (as in, on the shorter side), gives them far more tensile strength, so this is the way I would think it should be done. is this correct?

Second of all, should I lay them straight, parralel to the truss rod, or would I be better of fanning them inwards towards the truss rod, more closely following the taper of the neck?

Finally, because of the length they are, they cant cover the entire length of the neck, from heel through the nut. My neck is very close to an Ibanez wizard II neck in dimensions, so its pretty thin, and has a scarf joined angled headstock. My question is this: Should I mount the rods so they they go under the nut, tapering off at the base of the headstock, or just stop short of the nut all together ? Would going under the nut actually reinforce the headstock at all? A friend of mine casually suggested this to me, and my thinking was that, due to the angle of the headstock, it wouldn't be under the same kind of stress as the rest of the neck. But I figure you guys would know a lot more about this than me!

So, what do you guys think?

[Mattia]

I install them on-end, 1/8" (3mm) surface facing the fretboard gluing surface, and splayed slightly (following the taper, starting about 5mm from the edges of the truss rod channel at the nut end), although many folks just pop them in straight, works fine too. If the rod's long enough I usually run it past the nut and into the headstock as well, but I feel the veneers I glue on front and back usually add more strength than the small bit of CF does, although it will do something.

[Liam M]

Awesome! Thanks for your great reply Mattia! With all that resolved, I can set about getting some more work done, and hopefully have the neck all ready before the fretboard arrives.

One last question: I have a few glues available to me, PVA woodworking glue (not the water resistant kind), contact cement, and I think I have some 2 part epoxy somewhere. Will PVA do the job for gluing the rods in, or should I use one of the more permanent choices? Will this be something which will ever need to be removed (I'd think not, because if the rods go, I'd say the neck is in a few pieces), or should I just plan for the unlikely?

Thanks for all your help,

Liam M.

[Blackdog]

Awesome! Thanks for your great reply Mattia! With all that resolved, I can set about getting some more work done, and hopefully have the neck all ready before the fretboard arrives.

One last question: I have a few glues available to me, PVA woodworking glue (not the water resistant kind), contact cement, and I think I have some 2 part epoxy somewhere. Will PVA do the job for gluing the rods in, or should I use one of the more permanent choices? Will this be something which will ever need to be removed (I'd think not, because if the rods go, I'd say the neck is in a few pieces), or should I just plan for the unlikely?

Thanks for all your help,

Liam M.

And while we are at this, when should we glue the CF rods in ??

I read that it's a good idea to rough carve the neck as much as possible before gluing the FB on it, removing as much unnecessary wood as possible to allow the wood to "express itself" and make any corrections before the FB goes in. So, should we let the wood do its thing with or without the CF rods glued in ??

Thanks for sharing your experience !!!

[jmrentis]

I just recently had to get some opinions on this myself. It seemed that many people carve last and prefer it that way, but a number also prefer to carve early which is what I decided was the best route for me.

Mattia answered the CF/carve order question before I had even had a chance to ask. He said to epoxy in the CF rods before doing any carving. Then mostly carve the neck, lets it sit for a little bit, then do the fretboard installation. I believe thats what the process was. I recently did my CF rods with epoxy which worked fine,even though I used some crummy epoxy that made the process miserable. I've since switched epoxies to west systems which is much thinner, slower, and am very pleased with it. I also plan on using epoxy for fretboard installation upon the suggestion of several people whose advice I trust. Epoxy will avoid adding any excess water to the neck at that point, whereas woodglues will add a little bit of water.

So, epoxy in the CF rods and then carve. At least thats what I've decided on for the process. Also, always do all your routing for CF rods and truss rods before any tapering, cutting or carving. If you taper before you route, it can be a real pain in the arse to route channels. Mattia will have some better info, but thats whats I've collected as the process I want to use. J

[Mattia]

Pretty much what I do, yeah; clamping the rods is a pain with the neck carved, ergo I glue them in before pre-carving the neck. Gluing on the fingerboard (to a pre-carve) neck is easy enough if you leave the center area slightly flat (clamps are centered, force distributed by clamping cauls). I either epoxy or polyurethane glue the rods in, and epoxy the fingerboard on. Right now I'm using a 30-minute hobby epoxy which sands nicely, getting some boat building stuff soon which is better/as good and comes with handy pump dispensers.

And yes, slots cut before any other work is done if you've got a squared up blank. Makes things a little easier.

[nerosrevenge]

Can anyone post pics of this procedure?

Thanks,

STV.

[Mattia]

Can anyone post pics of this procedure?

Thanks,

STV.

Of what procedure? Routing straight slots in a neck and/or clamping something in a straight slot?

No.

[Jorge Fernandez]

Pretty much what I do, yeah; clamping the rods is a pain with the neck carved, ergo I glue them in before pre-carving the neck. Gluing on the fingerboard (to a pre-carve) neck is easy enough if you leave the center area slightly flat (clamps are centered, force distributed by clamping cauls). I either epoxy or polyurethane glue the rods in, and epoxy the fingerboard on. Right now I'm using a 30-minute hobby epoxy which sands nicely, getting some boat building stuff soon which is better/as good and comes with handy pump dispensers.

And yes, slots cut before any other work is done if you've got a squared up blank. Makes things a little easier.

Sorry for repeating (no english speaking), but, do you glue on the carbon fibers and later, with

the CF dry, you glue the fingerboard over it?

I'm asking because I've routed the carbon fibers channels and they are very adjusted to the

CF size and I don't know if glueing it will add something. I thought that I only will need to put

the CF and the truss rod on place and glue the fingerboard over it.

Thanks

[erikbojerik]

A thin layer of glue or epoxy should absorb into the wood and hold the CF rod in place at the same time. Wipe/scrape off the excess, make sure surface is still flat after it dries, then put the fretboard on.

You don't want the CF rods sitting in a channel with no adhesive; it is asking for rattle.

Edited September 27, 2007 by erikbojerik

[j. pierce]

What about press-fitting the CF in, and running water-thin CA glue over it, so it wicks in and adheres it?

I ask because I was doing a dry run before gluing some CF bars, and now I can't get them out. . .

[Jorge Fernandez]

A thin layer of glue or epoxy should absorb into the wood and hold the CF rod in place at the same time. Wipe/scrape off the excess, make sure surface is still flat after it dries, then put the fretboard on.

You don't want the CF rods sitting in a channel with no adhesive; it is asking for rattle.

Well, I thought that the epoxy used later to glue the fretboard will glue too the CFs to their surrounding wood

and to the fretboard, all in one step, to avoid scrapping the excess of epoxy used to glue the CF before glueing

the fretboard.

Thanks

[Mattia]

CA holds CF just fine, so that should work.

You want to get the bars in solidly, and if you're at all unsure about how level/flat they are, better to glue them in, sand everything flush, then glue on the fingerboard.