I've been asked to make repairs on this Tama TG-120, a good(high?) quality Martin copy. Another guitar left in it's case, in a closet, for years, unplayed. it will need a neck reset, among other issues. Has anyone had experience with these, and can say if it's a standard dovetail joint, that separates (relatively) easily, i.e. steam(or now, Stewmac's Heat Stick)?
Life is full of surprises, and for me, right now, this Tama is one of them. After making the other necessary repairs, I attempted to remove the neck. First with the Stewmac 'heat stick', then steam. It did not budge. I then removed the fingerboard extension, and can see no evidence of joint lines. It's not a Spanish heel: the two-piece neck block shows side grain, not end grain. I'm guessing it's either a tenon, or dowels, into the lower part of the neck block, which is covered(hidden) by the upper neck block, which is visible under the spruce. Unless anyone can ID this type of joint, I'm leaning toward a refret, and tapering the fingerboard, to improve the action. In the photo, I've removed small sections of the overlying spruce top, but found no joint lines(there is a faint line visible, but it's my knife line through the spruce).
Looks like a dowel joint - not terribly uncommon in 1970s Japanese guitars. . .
Agree, it is dowels. I did a 70s Samick that looked 100% like that, trussrod, joint, etc.. Probably made in the same factory.
Thanks for your replies. It good to know(at least) what the joint is. I'll know for the future. Palle, did you actually remove and reset the neck? If so...how did you remove it?
Yes, I sawed through the dowels and glue.
And then, correct the angle, and install new dowels?
Yep, redrilled the dowel holes once the neck angle was done. I also installed a threaded insert and a bolt through the neck block.
So, a thin bladed, no-set saw for the cut(I don't have Frank's nifty oscillating bone saw), and, what type of threaded insert: brass, fine thread? I tend to feel, if someone else has done it, then, durn it, I can do it too...
Can't remember what threaded insert I used, but probably fine thread. Don't think it is that important.
Palle, thanks very much for your replies.
A common wood screw is what I use, no need for a threaded insert. With the wood screw you don't have to remove as much wood in the neck heel. The hole should only be as wide as the center "stem" of the screw. The screw should have high and thin threads (see picture). The hole in the neck heel can be reinforced with thin superglue.