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Hello everyone. I have looked through the archives and I know some poeple have weighed in on this in the past. I have v have been using epoxy to join my CF and recently had an issue of delamination that I was surprised by. I always scuff up the CF with 80 grit. I have been using 2 epoxies, the WEST systems fast cure and Smith's all wood brand. The delamination was with the Smith's, which maybe is not surprising as it is most likely not meant for much except wood (as I understand it) but it had worked fine before. I have heard of people using fish and hide glue but I have not used those on CF.

I am mostly curious as to what other glues you all have used and if any things you have tried before have given you problems.

Thanks as always!

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Burton
http://www.legeytinstruments.com
Brookline, MA.

Hi Burton,

I've only used System Three 24hr epoxy on CF before and had no issues with it. I go a bit furher than you with the scuffing though - I take a very sharp scalpel blade and carve a fairly deep criss-cross pattern in the CF (I lean the blade opposite ways for each successive cut too) to give the glue something substantial to grab onto.

Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

Burton- I am just now 'experimenting' with carbon fibre neck reinforcement...and using medium CA. Very timely thread. Looking forward to what others are using, too....hopefully medium CA...

I use West Systems 105/206 for neck reinforcements. The only other place I use carbon fiber is in the upper transverse brace. I use hot hide glue there.

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Burton: Have only used CF as neck reinforcement and used epoxy as the glue.Will be interested in any answers you get.Have not had any problems except for messy clean ups after gluing.
Tom

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Burton...I use Smith epoxy on both neck reinforcing rods as well as laminated X-bracing. I also use this same epoxy to adhere the fretboard to the neck. I haven't had a problem so far. In the early years, I used hardware store epoxy with no delamination...that is until the stuff got too old and just wouldn't cure solidly.

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JJ
Napa, CA
http://www.DonohueGuitars.com

I started off using epoxy, lately I've been using polyurethane glue. Don't really remember why I switched.

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Matt Jacobs

"Don't tase me bro"

I'm thinking that since CF rods are made of carbon + epoxy, and (as far as I know) epoxies stick well to epoxies, that there had to be something still on your rods that did not allow the epoxy to adhere. Are there mold release agents used in CF manufacture? I'm not sure so I just assumed there are and that the surface needs to be cleaned thoroughly. I just started using CF, but I sanded all the surface sheen off, and wiped down with acetone, prior to gluing with epoxy, and on some parts I have used CA as the glue (on a recommendation by Rick Turner.)

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Burton-
I assume these are wood/CF braces, since you mention 'delamination'?
You probably know most all of this....
Some CF products have mold release agents used in their manufacture. so a good washing (soap and water and scotchbrite pad) never hurts, followed by a good solvent wipe (acetone or lacquer thinner). Epoxy needs a mechanical key, but your 80grit should provide that. If you are concerned about the keying, you can apply epoxy and then rub with 80/100 grit sandpaper to make sure the epoxy is in contact - that's how to bond aluminum with epoxy if you don't have the whole pre-etch kit handy.
Epoxy actually works a lot better if the epoxy layer is not too thin, so very moderate clamping is preferable. You should also pre-wet the wood with epoxy, and make sure your shop is warm enough that the epoxy is not too viscous. I also use thickener for all epoxy bonding jobs.
I've used a few different epoxies (not the Smiths that LMII sells, though) and I use WEST for most important jobs. I don't use a whole lot of CF, but I always bond it with epoxy.
I like the gap-filling property of epoxy-good for CF neck reinforcements where the slot is never perfect.

PU would probably work well for braces, but there you need firm clamping and a thin glue line.

Cheers
John
(Until a year or two ago, I bought epoxy in the 5 gallon jug!)

Thick CA or HHG. No issue so far.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I use 5 min epoxy I get from Dave Nichol's at custom pearl , He uses the stuff from SIG hobbies. Works so far.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Glue is overrated but when I do use glue on CF I use West Systems - a proud Meechigan product...

Been using Gorrilla glue and it seems to be working fine . I guess time will be the true factor here . I may have a or I may have . we shall see .

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Thanks for all of the replies everyone. The delamination was between 2 thin CF sheets from graphitestore.com. I was adding some layers under the steel square tube for a non adjustable neck. It sounds like an error on my part which is what I expected. It also sounds like many different glues work well.

I did not know that about the mold agent and i will be more careful in the future as to how I prep the surfaces.

Thank you!

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Burton
http://www.legeytinstruments.com
Brookline, MA.

For braces I use polyurathane glue as you can see in my tut. That is what Mario told me he uses and has been using it for some years. At the time I believe he was using the Elmers brand but I couldn't find it locally so I just used the clear drying Gorilla brand. Good tight clamping and fit is very important with the polyu glue.

Still using polyurethane glues, and my test pieces(some going on 11 years in ALL climates) are still fine. Elmer's "Ultimate" is my current choice; Home Depot has it, and it's the same as Elmer's "Pro Bond" poly glue. HD moves more of it, so it's often very fresh.

Epoxy, strangely, doesn't always like sticking to epoxy. And epoxy creeps; poly doesn't. Epoxy is heat sensitive(softens readily) and poly is 100% unaffected by heat. So, there ya have it; 11+ years of real-world use, and the reasons for the use. Just get yourself well setup for good, strong, even clamping(not hard...).