What kind of glue should I use on this repair?

[Ian Pender]

The guitar in question is a CA legacy model guitar, and its all carbon fiber. I've been calling CA for the past few days, but I haven't been able to talk to anyone, and they haven't returned any of my messages yet. Anyone have any ideas?

[Hesh Breakstone]

Is the bridge wood, ebony, or a composite?

What ever the manufacturer used looks a bit like it might not have worked very well...  It will be interesting to know what they used if you find out.

I found this video on line and it's interesting:  CA Guitars

Although I didn't catch the bridge installation they are using epoxy to assemble plates, etc.  One of the reasons that back in the day HHG was used in some instances for everything is that they only needed one glue.  Speculating here but even though we see CNC machines, composite materials, stainless steel frets, etc. - lots of technology...  It's still possible that the glue of choice for most every thing on these instruments is epoxy.  

Oh the horror...... ;)  

Ian if you find out from CA please let us know, inquiring minds want to know.  Thanks.

[Ian Pender]

The bridge is composite. The only wood on this particular guitar is the ebony fingerboard. The newer CAs don't even have that. Their fingerboards are made out of (in their own words) "a proprietary composite material similar to what the black graphtech nuts are made of". 

We were going to see if Peavy would cover this repair under warranty, but apparently Peavy has previously stated that they're not honoring warranties from before they bought CA. 

[Kerry Krishna]

I am thinking it will be crazyglue... 

[Andrew]

Id be leaning that way too. Any reason hhg wouldnt stick to this though? Ive heard of it being used with carbon fibre rods in necks. Why not here too?

[Mark Fogleman]

Epoxy is used to attach the fretboard to the neck in the video.  My money's on it being used for the bridge too but I would have a talk with the factory before going further.  I too would like to hear what they recommend and what you do as far as prep.  

I have a few friends touring with these and they are bulletproof as far as temperature extremes, humidity and rough treatment in the case.  Hearing the women talk in the video makes me miss Lafayette and Acadiana. It's Crawfish time!   

[Russell Vance]

Ian,

I havn't done this particular repair but I glue up graphite fibre each and everyday with epoxy (I use West Systems 105/106) and don't have any drama providing everything is measured very accurately, temperature is controlled and the materials are prepared as per the tech sheets.  I looked up high performance epoxies for shear and peel applications and the epoxy product (attached) seemed to fit the bill fairly well.   They stick airplanes together with this stuff and its branded/origin quality assured.  

You can bet its expensive but so is doing the job twice and pricing your reputation for failure.

I would use this if this job came my way.

Rusty. 

[David Collins]

Abrade and epoxy. If there's a layer of glue on top of the composite / resin layup remove that first as best you can, then rough both surfaces and bond it with epoxy. My default for most epoxy work for the last 20+ years has been West System 105/205, with appropriate fillers they provide for structural bonding, filling, filleting, etc. I've recently started playing with some System Three products designed for better heat resistance which may be more appropriate here (which is West System's only weak link I've found). I've never looked in to the LockTite product Russel pointed to, but it sounds like he's quite familiar with it so perhaps I should put it on my list of resources.

Most CA (cyanoacrylate, not "Compsite Acoustics") glues have too low shock resistance for my comfort in a bridge joint. Bonding is great, heat resistance is up there, humidity and creep resistance is the top, but with either sudden shock or repeated cyclical stresses it is just too brittle, and will be prone to either fail suddenly with shocks or fatigue and crack loose over time. Epoxies have that little extra bit of plasticity to make them more resilient and durable under constant loads.

Just be sure to follow the adhesive maker's instructions, use filler additives if recommended, and don't over clamp. CA guitars is owned by Peavey now, so I'm not sure if you'll be able to get to a tech support division for them specifically or just to the main Peavey support team. If you really want the best recommendations possible, I'd send the picture and question to the folks at Gougeon Brothers (the makers of West System). In all my years of working with their products, they have always been one of the most helpful and generous companies I've ever dealt with I terms of top notch expert customer support. With this joint being more akin to boat building than traditional guitar joinery, they could probably give you a more detailed specific answer than about anyone else.

[Mark Pollock]

First, I AM NOT OFFERING A SUGGESTION FOR THIS GUITAR.

But, as stated, the weakness of CA glue is how brittle it is. What about rubberized CA glue? It's a bit more flexible, and seems to be in the realm of possibilities for this repair, although I'm sure a quality epoxy would be preferred.

[David Collins]

Quite possible, but I just don't know enough about how the plasticizer may effect other properties as well, nor do I have any experience or testing under my belt with these plasticized CA's.

Plus there's the cleanup issue if you cover the entire surface well enough for squeeze out.

[Mark Pollock]

Ah, that is good reasoning. Thanks.

[Russell Vance]

Hi David,

Agree with all,   I use West Systems myself which is designed to lay-up laminates and similar boat building stuff , I noted the Loctite Epoxy because it was specific in its application for high shear and peel applications and had a prefilled makeup to account for irregular surfaces.   I'm not familiar with it other than to know Loctite as a quality brand from my previous experience with the Aerospace Industry and what I wanted to advise was a quality product with a guaranteed performance which suited the particular purpose described here. 

We are all going to see an increase in composite and hybrid material used in guitar construction and I suspect that we will end up knowing more about the repair requirements and schedules (due experience,  trial and error) than the original manufacturers.

Regards, Rusty.

[Ian Pender]

Hard to tell in the photo, but the residue left over does look like CA glue.

I'll contact Gougeon Brothers, and I'll let you know what they say. Epoxy sounds like the way to go.

Thanks!