Yamaha FG 140 - asian mystery glue - neck reset thoughts

[Mark Pollock]

I'm starting a new topic, since I seem to be running off in a tangent from Paul Verticchio's very nice posts.

My Yamaha FG 140, a red label with a LOT of wear and a badly shaved bridge, is coming apart at the bridge, and is starting to get a tiny flex crack around the bottom of the heel. This is my classroom guitar, and is the guitar I wish to continue playing at school, because 1) It can take it. 2) It's cheap, when some a-hole thief inevitably breaks into my classroom, I want him to take a cheap Yamaha and not some more expensive guitar. I don't want a cheaper guitar, since the Yamaha is actually highly playable and I like it a lot.

So, the neck joint is a dovetail with infamous "asian mystery glue". Now, I know that trying to loosen this joint with boring old steam is probably a no go. But, it occurs to me that it is probably some kind of epoxy of yellow glue, and would loosen with adequate heat.(And what kind of glue am I probably dealing with here?)

So, what would happen if I drilled the typical hole for inserting steam, but instead pumped hot air in, as well as applying heat to the neck block from inside? Is it possible I could loosen the joint without destroying the finish in the process? Heat does loosen glue, after all...

Yeah, I could just do the saw it off/bolt it on conversion, but I do want to learn how to do a neck reset, and this is a nice opportunity to play around without destroying a valuable artifact. As it stands, I cannot play this guitar anymore until I fix the problems involved.

Mark

[harrison phipps]

I have successfully reset necks on less valuable guitars like this one by a different method than removing the neck @ the dovetail.  With a sharp razor or Xacto, cut through the finish along both exposed edges of the back binding near the neck heal and loosen the binding out to the shoulders.  Work from the inside and outside with a pallet knife and a sharp box knife blade (use the box knife blade on the outside) and loosed the back from the headblock & sides until there is about 7 inches of back loose.  The neck can now be pulled back to an acceptable angle - look down the neck and it should point at the top of the bridge.  This is the angle where it should be glued.  The sides & headblock will slip into the guitar (towards the tail) when pulled back.  Note how much of the back protrudes past the sides at the neck heal when the neck is at the correct angle relative to the bridge - you will need to move it into this position when gluing.  Apply glue to the open areas, pull the neck back to the correct position & clamp.  After its dry, you will need to chisel the protruding back down flush with the sides and cut a new groove for the binding. 

[John McDonald]

Finally......a step by step of this procedure that makes perfect sense to me! Can't wait to try it out on a cheapo with a bad neck angle. Thanks Harrison and good luck on your project Mark!