# What type of glue would you use to bind carbon fiber to wood?



## Floppystrings (Mar 17, 2014)

Feel free to be as technical about two part epoxies as you want because I am willing to research. Or would you just use the original tight bond?

Say a guitar had 1/4" carbon fiber top, instead of figured maple. 

Here is an example of the carbon fiber in question (this piece costs over $700):

0/90 Degree Carbon Fiber Twill/Uni Sheet ~ 1/4" x 24" x 24"

I would prefer a glue with high heat resistance, fast drying time, and a very hard end result, almost crystalline if possible.


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## Dana (Mar 17, 2014)

epoxy. the slower the cure time the stronger the bond

jb weld would work but its not clear.

finishing resin is a long cure epoxy that become hard to the point its brittle. good for bonding and chemical resistant.. you may look into that


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## DistinguishedPapyrus (Mar 17, 2014)

This sounds ridiculous but I've had at least one good experience to back the following statements...

In a build I did about 4 years ago I used plain, white Elmers wood glue to hold a bocote fretboard onto a maple neck with two carbon truss rods. Later the build got botched due to issues with the body so I scraped the neck. Just to see the integrity of my build I tore the neck apart in a series of "stress tests" and discovered the wood glue that adhered the bocote onto the front sanded sides of the carbon actually tore chunks of wood out before the bocote separated from the carbon. The glue joint between the carbon and the bocote was stronger than the wood itself in some areas. I use Titebond these days but I have not yet built another neck requiring carbon rods so I cant say if Titebond is better to use, though I suspect if the carbon rod is sanded first, then titebond would be a good choice.

Stew Mac also says you could use wood glue in adhering wood and carbon: http://www.stewmac.com/shop/Truss_rods/Carbon_fiber/Carbon_Fiber_Neck_Rods.html?tab=Instructions


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## foreright (Mar 18, 2014)

I would be more interested in how you're planning to machine that CF laminate... Carbon Fibre is very nasty stuff - you REALLY don't want to be breathing the dust and splinters are extremely sharp and aren't rejected by your body - ie. if you get microscopic splinters, they remain in your skin to become potentially infected.

Having said that, I agree with Dana - slow curing epoxy is best.


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## Floppystrings (Mar 18, 2014)

foreright said:


> I would be more interested in how you're planning to machine that CF laminate... Carbon Fibre is very nasty stuff - you REALLY don't want to be breathing the dust and splinters are extremely sharp and aren't rejected by your body - ie. if you get microscopic splinters, they remain in your skin to become potentially infected.
> 
> Having said that, I agree with Dana - slow curing epoxy is best.



I will probably use several higher quality wide diameter sanding attachments with a router, I have a proper mask to use and attachments to suck in dust. For pickup routes, probably something similar with a sanding effect more than cutting for the edges. With the difference in density compared to the wood I am worried about a regular bit catching.

I know a bit about carbon fiber, I have had some piece before that I did some stress tests on, and you are kidding, when it breaks it's like glass/flint or something.


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## xwmucradiox (Mar 18, 2014)

Using that extremely expensive piece of carbon fiber plate is entirely unnecessary. Use a thin piece of carbon fabric and then clear coat it until it's buried. Wet sand and buff out. You could probably use resin and a vacuum bag to adhere it to a wood body.


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## Floppystrings (Mar 18, 2014)

xwmucradiox said:


> Using that extremely expensive piece of carbon fiber plate is entirely unnecessary. Use a thin piece of carbon fabric and then clear coat it until it's buried. Wet sand and buff out. You could probably use resin and a vacuum bag to adhere it to a wood body.



The idea around this is having the edge of carbon fiber with a very sharp round angle, like 6mm radius.

I will probably use a much cheaper thinner piece of carbon fiber, but I really want some depth to it. The twill weave looks the best to me, and it seems to be pretty expensive.

You can find carbon fiber pieces for less, I would like them to be pretty thick, hopefully under $150 for the top.


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## metaldoggie (Mar 18, 2014)

Distinguished - That is pretty much par for the course for wood glues, they are stronger than the wood.

I read in an article in Fine Woodworking magazine a while ago, where they glued up several wood joints (tight with no gap, normal and too much gap) with 6 types of glue (epoxy, gorilla, liquid hide, powdered hide, Titebond III and regular elmers.
They tested all the bonds with an Instron to get stress numbers to compare the strength of the glues. 
I don&#8217;t remember the complete results, and if I find the article I will post it, but I know the Titebond came out on top and gorilla was the worst. I think epoxy was in the lower half and powdered hide was better than liquid hide. All the joints broke in the wood meaning that all the glues were stronger than the wood itself.

EDIT: Found it http://www.oldbrownglue.com/images/articles/HowStrongisYourGlue_FWW.pdf Got my order slightly mixed up though...and some of the results. Should have read it all again first lol.


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## Floppystrings (Mar 18, 2014)

Nice, good information there. Thanks.


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## DistinguishedPapyrus (Mar 18, 2014)

metaldoggie said:


> Distinguished - That is pretty much par for the course for wood glues, they are stronger than the wood.
> 
> I read in an article in Fine Woodworking magazine a while ago, where they glued up several wood joints (tight with no gap, normal and too much gap) with 6 types of glue (epoxy, gorilla, liquid hide, powdered hide, Titebond III and regular elmers.
> They tested all the bonds with an Instron to get stress numbers to compare the strength of the glues.
> ...



Thanks for the post, good info all around for wood working... but I still wonder what results could come from tests like this using carbon fiber and wood?

I had descent results from gluing wood and carbon fiber using regular white wood glue such as Elmers, thats after sanding and preping the piece of carbon fiber as if it were a piece of wood. The carbon fiber I used were StewMac reinforcement rods, where the fibers are not woven but all aligned in a single direction.

EDIT: I actually still have one of those pieces, I kept it cause I thought it was cool to see the results...






This is after picking as much of the wood off as I possibly could by hand.


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## metaldoggie (Mar 19, 2014)

Carbon fiber is fairly porous so it should be easy to get good bond as long as it's free of dust.

The adhesion of the glues is very much dependent on the porosity of the material you are gluing, e.g. glass is very smooth down to the molecular level and therefore really difficult to adhere to something.

As far as the types of PVA glue - the "Type I or Type II" refers to the ANSI standard they were tested to....I don't know the specifics, but I know one test involves boiling a glued part for a period of time an testing the bond strength after that.
Type I glues are the strongest, Type II is lower strength etc....


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## xwmucradiox (Mar 19, 2014)

Floppystrings said:


> The idea around this is having the edge of carbon fiber with a very sharp round angle, like 6mm radius.
> 
> I will probably use a much cheaper thinner piece of carbon fiber, but I really want some depth to it. The twill weave looks the best to me, and it seems to be pretty expensive.
> 
> You can find carbon fiber pieces for less, I would like them to be pretty thick, hopefully under $150 for the top.



The top layer of weave would have ~99.9% coverage so multiple layers wouldn't make a difference in "depth." That plate is only laminated with weave on either side. The center which is most of the thickness is just uniform fibers with no weave. A black dyed maple top with carbon fabric laminated on top would look extremely similar.


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## Floppystrings (Mar 19, 2014)

xwmucradiox said:


> The top layer of weave would have ~99.9% coverage so multiple layers wouldn't make a difference in "depth." That plate is only laminated with weave on either side. The center which is most of the thickness is just uniform fibers with no weave. A black dyed maple top with carbon fabric laminated on top would look extremely similar.



It would look similar, but would it be as flat?

The twill weave looks different the thinner you go, and I want the effect on the edge, and then some. kind of like binding. (the wood will be dyed a different color, to contrast the dark edge).

The bridge will also be mounted directly to the carbon fiber, so I am looking to get some unique tonal qualities too. The body will most likely be chambered and 1 1/2" thick.

I have no issues about the carbon fiber thickness, I have seen 1/4" thick piece go for $90. One side glossy, one side raw finish. Basically just what I am looking for. I am all about searching bargain bins for the right pieces.


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## Pikka Bird (Mar 19, 2014)

xwmucradiox said:


> The top layer of weave would have ~99.9% coverage so multiple layers wouldn't make a difference in "depth." That plate is only laminated with weave on either side. The center which is most of the thickness is just uniform fibers with no weave. A black dyed maple top with carbon fabric laminated on top would look extremely similar.



Yeah, if I read the page (and see the picture) correctly then it's one sheet of criss-crossed weave on top of a layer going in x-direction, a layer in the y-direction, another in the x, etc.

I think homemade Micarta made from black twill fabric and then topped with a single sheet of carbon fabric would look 99% identical to this if the look is all that matters. Since you're already looking into epoxies, Micarta will be a breeze to make- check Youtube for instructions.


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## xwmucradiox (Mar 20, 2014)

Floppystrings said:


> It would look similar, but would it be as flat?
> 
> The twill weave looks different the thinner you go, and I want the effect on the edge, and then some. kind of like binding. (the wood will be dyed a different color, to contrast the dark edge).
> 
> ...



I suspect all the resin and differently-oriented layers in a thick piece of carbon plate would make it rather dead acoustically. So maybe "unique" would be a good way to put that.


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