Carbon Fiber Neck Laminations

[Mehnike]

First off, I really appreciate all of your time and expertise. It's a great forum we have here. I tried searching with no result on this specific topic. Please correct me if I have missed a thread.

Has anyone here successfully utilized carbon fiber sheets between neck laminations? Would you care to share how it went and where you sourced your carbon fiber?

Similar to what I believe Strandberg is doing (or use to), I'm toying with the idea gluing up thin (.012 - .025") strips of woven carbon fiber along the entirety of the neck lamination. This would mean using epoxy to glue up rather than PVA glues. I've previously used System Three T-88 Structural Epoxy in a fretless conversion where fretboard was covered with 1/16" thick layer and I have yet to see signs of cracking or delamination after 5 years. While T-88 seems like a fine choice, do any of you have epoxy recommendations that you prefer over the T-88?

Finally, what are your thoughts as to how much this would actually increase neck stiffness versus the traditional 5 piece glue up with PVA? I'm expecting most to say this is all overkill, and I understand that it kind of is, but I'd like to give it a go.

 

[morgdav]

I recently tried this and now have an uncuttable neck blank. Perhaps using "upcycled" aerospace grade carbon fiber was not the best choice, but it destroyed any tool steel I have. I could buy a cutter for the CNC but that would likely be terrible on the wood.

 

[Mehnike]

Hmm, that I did not yet consider. When you say tool steel are you referring to HSS? I can access carbide tooling (jointer/planer) if necessary.

How thick was your CF? Care to share any pics of your results?

 

[morgdav]

I don't remember the exact dimension but looks to be about 1.5mm

It will destroy carbide. I had to rotate several of the cutters on my jointer.

 

[bostjan]

Never integrated CF myself into a guitar neck (I've never made a guitar neck), but the stuff you buy from McMaster-Carr (or whatever generic supply house) is machinable just like fiberglass. I'm sure each grade of the material is different, though. I was looking for what we've used in the past where I work, and couldn't find it, but we just cut it with regular old tools. It's rougher on blades and bits than wood products, but so are most composite materials (we also use a lot of GPO3, and that stuff is much worse than the CF stock we have), and it's not really a big deal other than the awful smell and nasty itchy dust that gets everywhere.

I guess just don't use the same CF that they use on the ISS or whatever, and it should be okay to cut as you would cut a tougher hardwood.

 

[morgdav]

Agreed. There are a lot of different grades. If the goal is to add stiffness (as mine was) then very thin or loosely woven sheets aren't likely to do much. Just for reference, I got mine from https://www.rockwestcomposites.com. I will also mention that I have a Strandberg with the thin carbon laminates and it is not any stiffer than the necks on any other guitar I own.

 

[foreright]

Never integrated CF myself into a guitar neck (I've never made a guitar neck), but the stuff you buy from McMaster-Carr (or whatever generic supply house) is machinable just like fiberglass. I'm sure each grade of the material is different, though. I was looking for what we've used in the past where I work, and couldn't find it, but we just cut it with regular old tools. It's rougher on blades and bits than wood products, but so are most composite materials (we also use a lot of GPO3, and that stuff is much worse than the CF stock we have), and it's not really a big deal other than the awful smell and nasty itchy dust that gets everywhere.

I guess just don't use the same CF that they use on the ISS or whatever, and it should be okay to cut as you would cut a tougher hardwood.

Just to add, CF dust is seriously bad news - that "itchy dust" is something you don't want to be inhaling (or realistically getting on your skin if you can help it...). The dust is also rather conductive and not great for your electronics if it gets in there either