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Look Ma, no bracing! (Carbon Fiber)
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Author:  rlrhett [ Tue May 19, 2015 12:33 pm ]
Post subject:  Look Ma, no bracing! (Carbon Fiber)
I don't usually post my builds, but this one took a year of experimenting and a half dozen failed guitars so I thought I would share:
Author:  WudWerkr [ Tue May 19, 2015 12:36 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
LIKE !! Sound Clip ??
Author:  Quine [ Tue May 19, 2015 12:46 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Nice. Very classy looking combination of wood and carbon fiber. Definitely calls for a sound clip
Author:  Glen H [ Tue May 19, 2015 1:09 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
COOL. Definitely... gotta hear it!
Author:  Gasawdust [ Tue May 19, 2015 1:20 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
I've been thinking along these lines but keeping a traditional look with the carbon fiber patch on the inside. I'm sure it's been done but don't know by whom.
Great looking work...let's hear it.
Author:  PeterF [ Tue May 19, 2015 2:50 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Wow that's gorgeous! I love a bit of polished carbon fibre :D How easy was it to finish? Did you have to do a few coats of epoxy to fill the weave after moulding it? Was it vacuum bagged or hand laid up?
I've always thought carbon fibre would be far more useful on an archtop than a flattop because of the enormous stiffness it has in a compound curve. It's funny you hardly ever see them.
We definitely need a soundclip!
Author:  dzsmith [ Tue May 19, 2015 5:59 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Coo-ool!
Author:  sdsollod [ Tue May 19, 2015 7:11 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
That is very cool. Nicely done. I like the maple with the carbon fiber. Nice contrast...
Author:  rlrhett [ Tue May 19, 2015 7:16 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Well I'm not sure how to post a audio file. I've wasted a lot of time trying to add an audio attachment. This system has told me that mp3, acc, wav, aiff are all not allowed. In any case, I don't really have a good recording solution right now. Just was going to do a quick upload of a recording I did with my iPod, but the recording really doesn't do it justice.

My unbiased opinion is that it sounds fantastic! :D It's no pre-war Martin, but that was not the sound I was going for. It has tremendous volume and sustain. One person hearing it played asked where the "amp" was. It almost sounds like I've added reverb somehow. It has great clarity without sounding tinny or brassy. It just sounds clear, clean, and "precise". Playing it A/B with another archtop I built (that I LOVE) it sounded like the wood one had cotton balls in the sound hole. It also has amazing dynamics. Light touch to heavy produces very different volume with similar tone.

On the negative, it doesn't love big full six-string strumming. This is a guitar for martinis and bar tables, not joints and drum circles. Indifferent strumming leads to a muddy flat sound.

To me it sounds exactly like what I would hope an acoustic archtop should sound like. Rich, full, clear, pure. I've been chasing this sound for a relatively long while and am pleased to have this result. There is more I can tweak on the next one (and the next one, and the next one), but overall I consider this a pleasant and surprising success.

I've sold it, so I don't know if I can get a decent recording of it even if I could figure out how to post one. But I can say that at least one other musician was enchanted by the sound ;) .
Author:  rlrhett [ Tue May 19, 2015 7:24 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
PeterF wrote:
Wow that's gorgeous! I love a bit of polished carbon fibre :D How easy was it to finish? Did you have to do a few coats of epoxy to fill the weave after moulding it? Was it vacuum bagged or hand laid up?
I've always thought carbon fibre would be far more useful on an archtop than a flattop because of the enormous stiffness it has in a compound curve. It's funny you hardly ever see them.
We definitely need a soundclip!



The top was laboriously "filled" with shellac. Apparently one needs to "pore fill" carbon fiber or the weave telegraphs through. Guess how I found out! In the future, I will "pore fill" with epoxy.

The carbon fiber is bagged, but not vacuum infused (if that is what you are asking). It took six failures before this one held. Funny thing about carbon fiber is that it is not wood. I had to throw out a lot of assumptions on how to brace, where the weakness would be, etc. Yes it is strong in some ways but weak in others. Dumping six guitars in the trash (tops are epoxied on, and can't be steamed off) is a painful process. I can see why you don't see a lot of other luthiers trying this. Still, now that the R&D is mostly done I am glad I jumped down this rabbit hole!
Author:  Mike OMelia [ Wed May 20, 2015 6:59 am ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
So, if I understand, the top is pure carbon fiber, infused with epoxy and finished in shellac? No bracing?
Author:  rlrhett [ Wed May 20, 2015 10:08 am ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Mike O'Melia wrote:
So, if I understand, the top is pure carbon fiber, infused with epoxy and finished in shellac? No bracing?


Yup. You got it.
Author:  kencierp [ Wed May 20, 2015 10:13 am ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Very cool project. Congratulations on sticking with it -- way to go!
Author:  Johny [ Wed May 20, 2015 11:50 am ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
That is crazy cool.
Author:  jfmckenna [ Wed May 20, 2015 1:20 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Do you have a thread somewhere that shows the building process. that's one super cool looking guitar there and I love the sailboat inlay on the headstock. The way you describe the sound is similiar to the way I would describe the sound of the Selmer guitar I built. It sounds awful when you strum full chords but it's got it's own reverb and amped up sound.

That's beauty, good job [:Y:]
Author:  Barry Daniels [ Wed May 20, 2015 3:00 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Can't imagine how you would rout the binding ledges. Maybe a water knife?
Author:  lactose [ Wed May 20, 2015 4:01 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Beautiful. I would think the sonic delta between arched CF and arched wood is much less that of flattop CF and wood. So sound-wise this makes sense to me. I too am curious about the binding ledge.
Author:  rlrhett [ Thu May 21, 2015 11:02 am ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Binding ledge was cut with a regular carbide downcut end mill in a router. Carbon fiber will dull blades, but a couple of laminated woven sheets are far less hard on tools than extruded rods. The F-holes are likewise cut with a 1/8" end mill/router. I ended up doing quite a few of those and the bit is still cuts just as well as before.
Author:  Jim Watts [ Thu May 21, 2015 8:04 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
That's good work!
Author:  Jimmyjames [ Fri May 22, 2015 9:47 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
When I looked at these pictures I heard an authoritative German narrator akin to a Porsche commercial.

"This guitar will accellerate at speeds of 100 kilometers per hour in less than 3.1757 seconds..."

Nicely done.

-j
Author:  kencierp [ Sat May 23, 2015 10:57 am ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
I've only used CF a few times -- the warning and precautions I got with the material were pretty scary.

Is this a health concern?

Quote:
Binding ledge was cut with a regular carbide downcut end mill in a router.
Author:  Dave Fifield [ Sun May 24, 2015 10:28 am ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Very cool! Nice work!!

Dave
Author:  PeterF [ Sun May 24, 2015 1:45 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
kencierp wrote:
I've only used CF a few times -- the warning and precautions I got with the material were pretty scary.

Is this a health concern?

Quote:
Binding ledge was cut with a regular carbide downcut end mill in a router.

Not really any more than working with other nasty materials like mdf or some of the worse tropical woods like cocobolo. Of course you don't want to breathe it in, so a dust mask is a must. If you're sensitized to epoxy, the dust can irritate your skin too.
But if you take the right precautions its perfectly fine to work with.
Author:  giltzow [ Mon May 25, 2015 3:27 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
Wow!! Really like what you have done there. Spectacular!
Author:  cphanna [ Mon May 25, 2015 5:27 pm ]
Post subject:  Re: Look Ma, no bracing! (Carbon Fiber)
I played a carbon fiber topped flat top in a music store quite a few years ago. At the time, I had no idea what to make of it, but it DID seem rather alive and responsive. Now....that's a memory that was hazy at the time and has grown more hazy with the passage of years. I don't have a sufficient memory of the experience to evaluate that guitar against a fine wood-topped instrument. I just liked it as I played it, and there's no need to read anything into that.

My question about your archtop is this: Are we looking at carbon fiber layered onto spruce or other wood? Or are we seeing many laminated layers of carbon fiber?

Okay...another question: IF the arch top is all carbon fiber, did you carve the mold for the top and laminate and vacuum clamp it? If yes...then would you be inclined to post photos of your process so we can all learn about your technique?

Best regards,
Patrick
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