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Hi Friends,
I thought epoxy was the right glue to use when inserting carbon fiber rods to stiffen guitar necks. I have an old (40s) Recording King jumbo in the shop that has too much relief. The neck is Poplar and it has no truss rod, so I am going to insert two 1/8" x 1/2" cf rods the length of the neck. I was watching a few videos before getting started and saw that Dan @ StewMac used fish glue to hold CF rods in place. Which got me thinking if fish glue works, wouldn't PVA, too.

Does anyone have any thoughts on this? My bias is towards epoxy, but this has got me thinking maybe that is overkill.

Regards,
Geo

I had a carbon fiber rod that hide glue would not stick to. For some carbon fiber, it will. I talked to a maker of carbon fiber rods who said that his will. The takeaway for this query is that you probably ought to test the rod you have with the glue you want to use.

One of the problems that I have with carbon fiber rods is how tight they ought to fit. The gap has to be small enough that you get a good glue joint but large enough to let the excess glue (epoxy) out. I split a neck with glue pressure trying to seat a carbon fiber rod (which fit just fine without glue). I never have mastered carbon fiber. My solution is to not use it. Others have had success.

I always cleaned the carbon fiber rods first with lacquer thinner. I just assumed they might be contaminated with a release agent. I can't recall what I used back in the 80's when I glued CF rods into bass necks, but these days I just use Titebond. Once the fingerboard is on, the rods aren't going anywhere. I make sure they fit tight - no room to vibrate.

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"Act your age, not your shoe size" - Prince

I’ve always used epoxy with no cleaning. No problems although maybe I got lucky. Didn’t think to try other glues.

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Steve Smith
"Music is what feelings sound like"

Splitting is a real possibility. The neck is pretty weak even for Poplar. These were Montgomery Ward's catalog guitars, I doubt they were thinking about 5 years down the road, much less 80.

Maybe that is how epoxy started getting used. Thanks. PVA seems to stick to it, I've just never considered anything but epoxy. Thanks.

Thanks Chris. I prefer Titebond unless I really can't use it. Maybe I'll save the epoxy for the broken flower pot on the porch.

Right, same. I never considered using anything else, until I saw Dan using fish glue, but it looks like some folks have had success with other glues. I tested a piece of the CF and I can glue a piece of Poplar to is and it is not going anywhere. Thanks.

I’ve used CF once outside of aircraft, keep in mind my lack of experience.
If the rods aren’t going anywhere is the glue that important?
Maybe to keep the rod from sliding in the slot?
If you controlled the length of the slot to match the length of the rod
could you get away with no glue ?

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Say what you do, Do what you say.

I guess, Dave - but I'm a luthier so glue seemed natural.

_________________
"Act your age, not your shoe size" - Prince