Carbon fiber top plates

[Peter Laine]

   I am primarily a boat builder and cruisers are my primary clientele. I have been thinking of making a carbon fiber guitar ( back,sides,neck, wood top  ) to try and solve a major seagoing guitar player problem, ( humidity, and lots of it)  this project has sat on the back burner  for a while.    However I just got a call from a boat in Grenada who is coming to Trinidad only to get me to put carbon fiber tops on two guitars he has ( ovation and a Tanglewood bass)    I really don't like the sounds I have heard from CF guitars, as my personal preference runs to more full and "woody" bass tones.   Cumpiano is building and touting a CF top on a wood body, ( which sounds backwards to me , but how can I argue with a guru who's book gave me a foundation of sorts) .

does anybody know what is cutting edge in this area? is anybody getting closer to a bassier sound? is it all proprietary and secret?  I have committed to looking into this for this client, and and insight would be appreciated, no matter how esoteric.   At present the idea that feels right, so to speak is a thin spruce veneer with thin ( 5 0z or less) 2x2 twill skins, and no bracing, but this is in no way an educated opinion. I am not mathematical.  I will no doubt have to spend a few hundred on carbon and experiment a little, I will report on what I find in this forum but any info at this stage would be a time saver .

[Mario Cardenas]

I really don't know much on the subject. There are doble tops with a layer of nomex (i believe) in the middle. A haven't heard those CF tops you mention. If you have a link i'd like to hear them. In my opinion i'd wait for more applications of graphene to developed. I think it is gonna make really good material for tops. But just a guess.

[Paul Verticchio]

Hi peter.

This may sound like a ditch & run response, but I assure you, it's not.

In the world of carbon fiber or composites, EVERYTHING is custom designed & manufactured for its specific application. With composite guitars, the radii of the tops and backs are molded & set when they are being manufactured.

Most of the 'stock sheets' available are for fabrication of 'cosmetic' items.

I believe your best and only source of the answers you seek are the engineering departments of composite fiber manufacturers.   The only real thing I can assure you of is that this endeavor will be extremely expensive.

Your friend may not know it, but it will be much cheaper and cost effective to buy a used Ovation Adamas series guitar than to convert his to a composite top. They've used composite tops for decades.

I don't see a lot of research being done, except by the experimenters you've mentioned. When I asked myself 'why' it became apparent... It's just too expensive to prototype and build an instrument which will please the masses and be cost effective.  Once you begin talking instruments in the several thousand dollar range, folks simply demand premium timbers, not composites.

However, in summary, this is an engineering project and contacting the design/engineering staff at composite manufacturers' sites will yield not only the best answers, but the "correct" answers. It's pure science so terms like "maybe, it might, I thought, I heard, etc" are a complete waste of time.

Best of luck with your quest :).

[Peter Laine]

Paul;

   thanks for the reply, I have been watching, 99 views ..no comments.    I have built carbon fiber boats, and I have worked in more mundane composites for years and I'm aware of the engineering that goes into a composite structure, indeed that is the coolest thing about them, engineering in strength only along the load paths and  leaving material ( and weight ) out where it is not needed,a custom, specific,"anisotropic " material. 

      However engineering for sound is another ball of wax. those who have spent the time ( & money ) to come up with a laminate schedule are understandably closed mouthed about the path they're on , and there is always the hype component.  I'm going to have to shoot in the dark a bit.   the cost is not so awful,  5-6 gram material is in the $20 per yard range, you should be able to get 4 layers out a 51x36 pc so for the cost of an inexpensive spruce top and $20 in carbon, we're off, I like the curvature idea. I'll let you know how it works out.

thanks again for your two cents

[Paul Verticchio]

Just for clarification: the expensive part would be applicable only for developing a schedule for producing acoustically responsive composites. As a professional user, you know that sound dampening is one of the desirable features the product. Engineering that out is the difficult part.

I'm sure most MI builders have proprietary formulas and they're considered trade secrets. You might want to check the US Patent Office to see if there's anything there which may be helpful.

Digression: 20 years ago, James Taylor was interviewed in an acoustic guitar magazine.  He mentioned that the craftspeople that he admires most are boat builders & acoustic guitar builders.  I agree 100% with that observation, so I think this quest is in very good hands with you. :) :)

Thumbs up for much success !!!!!

[Robbie Collins]

I'm with James Taylor on the craftsmen.  I like to peruse the occasional copy of 'Wooden Boats' myself. I've considered going to a 2-week boat building course in Maine several times.

[Russell Vance]

Hello blokes, 

Good boat builders are a product of Darwinian theory...the bad ones drown.   Acoustic guitar builders suffer no such consequences........

Agree with Paul on this one - there are so many different types of CF and associated bonding/curing processes to work through - not to say it can't be done - but those who work it out aren't telling.   The CF bike frame guys are a good place to see this secret propriety process in action.  

I suppose the place to start is to build a CF soundboard to a strength equivalent of spruce or similar and then conform and brace it so it resonates similarly when excited.  

Rusty.

[Peter Laine]

this is a late reply  and I don't want to be pedantic, but if anyone is seriously looking into this sound deadening is not associated with CF.  in boats  the saying goes " it's like living inside a guitar"  the material transmits vibration so effectively that you hear every little wave slap, foot step, and  sheet ease, it's noisy enough to drive you crazy.      a point to ponder while researching the subject

[Frank Ford]

I'm surprised that no one has mentioned Rainsong guitars yet.  They've been somewhat the standard of the graphite composite acoustic guitars, and they are readily available.

Early examples had conventional bracing size and pattern, and had nearly no acoustic appeal.  Current versions are a different story. . .

[LARRY KLOSE]

There's a nice interview with the carbon guru at McPherson guitars in the most recent (I think)) issue of Acoustic Guitar magazine.  The same guy started CA Guitars a number of years ago, which made some of the better sounding CF guitars.  I have no first hand knowledge but it sounds like there's a lot of serious engineering involved in designing and fabricating tops and indeed, the rest of the guitar.  Might be worth a read to get a handle on the scope of the project.

Larry

[Peter Laine]

Thanks, for better or worse I'll post some observations on how this attempt ( carbon skin /spruce core)

turns out