Carbon fibre lamination and truss rods

[IWieldTheSpade]

Hi all,

Hoping to pick the brains of those of you on here with composites experience. I've been doing a lot of thinking lately (which is mighty distracting when there are two projects on the bench at the moment) about various techniques in neck construction. Carbon fibre specifically has always been a bit of an interest of mine, since my very first bass build actually, and I love its versatility in musical instrument applications. So naturally my mind wandered towards the ways I could incorporate it into a neck. Of course, the first port of call was looking into entirely carbon necks and one thing I read struck me as quite interesting - built correctly, a carbon fibre neck is stiff and stable enough to not require a truss rod.

Unfortunately, I am very much an oiled timber neck type person, and any finish that approaches plastic-y in feel tends to put me off a bit. Not that I would refuse an instrument with, say, a poly finished neck on it, but when making your own it should be completely how you want it right? With that in mind, I arrived at the idea of your standard laminated neck but with carbon fibre stringers between each section of timber: timber feel but with the added rigidity and stability of carbon. I've seen a couple of examples of this done before, but nobody seems to have ventured much beyond 2 or so carbon stringers.

So at this point I'm wondering if anyone has thoughts on how much carbon fibre would be needed along with an appropriately sturdy timber to be similarly stable to an entirely carbon neck, enough to not need a truss rod anymore? Or should I stick to having the option of neck adjustment?

 

[JMorciglio]

Have to check in a week or so?
Plan on stringing this up before slotting for frets.

The "binding" (outside stringers are a full 1/8" thick and run through the heel.
Then the heel was capped on the bottom.
After the shaping is done, there is quite a bit of depth left over.

Have always ran 2 full depth stringers on all my hybrid necks.
Build them like this for the same reason you mention; the "feel" of wood.

Two stringers are plenty stiff but I always ran truss rods. (until this one)



3 would surely be strong enough.

JM

 

[JMorciglio]

Darker woods look real nice with the carbon laminates.
Always end up tinting the maple/carbon necks.

JM

 

[IWieldTheSpade]

Wow @JMorciglio that is a great looking neck. Nice to see more carbon fibre love around. I'm glad others have arrived at a similar design, makes me feel a little less crazy What type of fingerboard are you using with it?

Darker woods look real nice with the carbon laminates.
Always end up tinting the maple/carbon necks.

JM

I have a pretty dense Australian timber that I thought I'd use, it's a deep earthy red that I think will go nicely with the carbon fibre. Being a pretty hefty timber in itself (close to ebony in density) it should hopefully let me get away with a thinner profile neck too.

 

[craigie]

Any problems with gluing / shaping the composite necks?

 

[SLivinghouse]

Have to check in a week or so?
Plan on stringing this up before slotting for frets.

The "binding" (outside stringers are a full 1/8" thick and run through the heel.
Then the heel was capped on the bottom.
After the shaping is done, there is quite a bit of depth left over.

Have always ran 2 full depth stringers on all my hybrid necks.
Build them like this for the same reason you mention; the "feel" of wood.

Two stringers are plenty stiff but I always ran truss rods. (until this one)



3 would surely be strong enough.

JM

Oh Man! I was going to try something like that. LOL, not that I have the skills to execute that at this time, but hey, that's pretty much what I had in my imagination for a future build.

OP, You saw MPU's build in the Winter build off right? If not check it out.

 

[IWieldTheSpade]

OP, You saw MPU's build in the Winter build off right? If not check it out.

I've been following it intently if that's what you mean Inspiring stuff that's for sure, and I think it was in that very thread where I first saw mention about carbon being able to be too stiff for truss rod use if built up enough.

 

[JMorciglio]

Any problems with gluing / shaping the composite necks?

Harder than honduran hog , maple is closer. have to use solid sanding blocks. Try to "machine away as much as possible before final sanding.
A "neck profiling" jig/fixture would help.
Gluing/laminating is more time consuming, (have to "wet out" each layer), use epoxy.
"plates" (could) be glued with regular titebond.

Fret boards can be anything from carbon, to rose wood or ebony etc.

 

[Carbonista]

As someone who has recently started building basses and is a big fan of Zon necks, this thread is very intriguing.

JMorciglio, how would you characterize the acoustical properties of the carbon laminate necks you've built? Longer sustain? Any dead notes? Does the tone become more sterile as some people experience with Modulus necks?

 

[JMorciglio]

Haven't really "A-B'd" them.
From when I researched "dead spot", would think two really dense, full-depth stringers of any material would eliminate them?

They do seem to have that "piano-like" quality?
Really strong sustain.
Stable. Stay in tune well.

Some of the archtop and acoustic luthiers (guys on discussion forums)
imply you can build a "too-stiff " neck?

Built quite a few "full-carbon prototypes before coming up with a formula.
The wooen/carbon hybrid necks feel "warm" to me. Not sterile?
Never owned an older full graphite neck to compare.

Played both the Kramer and Travis Bean basses WAY back in the day and really liked them both.
Had a 64' Jazz, 77 Ric. and a 2900.00 Alembic throught the 80's and late 70's when I played in working bar bands. So never needed one, but wanted them.
Was told even back then the Aluminum changed with temp so tuning had to be adjusted?

JM

 

[IWieldTheSpade]

Some of the archtop and acoustic luthiers (guys on discussion forums)
imply you can build a "too-stiff " neck?

From what I've read recently, it was something about "driving" the body properly in an acoustic instrument. Not something I'm familiar with, being mainly an electric builder, but it seems to be more of an acoustic resonance thing that they are concerned about. Not an issue for an electric instrument at least.

Do you think that having the carbon stringers could possibly bypass the need for a scarf joint in an angled headstock design, or would short grain in the timber still be a worry?

 

[JMorciglio]

No scarf joints with the stringers.
Personally don't like scarf joints. (like butting end grain to flat grain)
Have seen them open up on older stuff?

12 degree on the archtops, 6 degrees on the slotted headstock. (could be even less)
Use 10- 12 on electric solidbodies also.

JM

 

[JMorciglio]

I also picked up some basses and played them unplugged to see if you can feel any difference
with the carbon stringers.
Quite profound actually .
An Explorer bass I whipped up in the 80's (Entwistle Style) w/ Fender bolt-on neck,
Has a brass nut. You can feel/hear the difference from open string to fretted.

Makes me wonder about harder/denser fret wire?

I would say anybody could feel the difference right away. Plugged in???
Only have 1 six string (Ovation Elite from the early 90's), with a traditional neck.
This guitar sounds great, plays great and I would never sell it even if my carbon flat tops start to sound as good. VERY loud (bass players perception of "tone")
Plays like an electric with the hard "V".

This is my benchmark when building archtops.

Does the neck "drive" the top, ????

Also have a 5-string custom shop matching bass. 34" scale
The bridge is "pulling" on this one so I have not messed with it for a while.
Also, don't play or like 5-strings. Will string it E-C when I get around to re-gluing the bridge.
(they tried to talk me into a carbon top at the time as I really wanted an Adamas)

I was like, "carbon, NO WAY". Little did I know within 5 years I would be building racing kayaks,
and othe whacky/cool stuff from it.

Bridges were pulling on the 5-strings and they started making them in shorter scale only,
(rumor I can't confirm or deny)
Thats why I ordered the bass to match the 6-string.

JM