Yamaha FG75 dovetail location measurements

[KT Vandyke Frog Level Guitar Shop]

This is great, I have one of those in the shop as well speak. Thanks for sharing!

[Michael Hermer Brenzasi Guitars]

Hello Tony, I just completed an FG-75 reset and hit the pocket right at the 15th fret. I used heat (and it eventually worked), however I’m sure Dave would advise that steam and water is more effective than dry heat with the historically famous “Yamaha glue” used in the early 70’s)!

[Tony Lewis Skypilot Guitar Repair]

https://youtu.be/GjcX1MZUzYI?si=pVJINHwZgmcGTkfy I used four heat probes. Came off in twenty minutes . I was up to speed after doing two other early 70’s FG neck resets and am well aware of Yamaha glue mess. I use four probes minimum on every neck reset I do now. Get lots of heat directly to the glue joints. I would, at this point, argue that this is much more efficient as you can drill and get a probe right down into glue joint on the sides of the dovetail, not just the pocket, which steam only gets to. You can heat up areas that steam can’t hit. And, as you know, steam makes a mess and a good chance of misting the finish. With this system. You can put as many probes on with different wire sizes. With foam cutters, your stuck with one size. I’ll send pics of hole locations I used on the 75.

[Tony Lewis Skypilot Guitar Repair]

So one of the pics shows the probe pattern I used. This was a guess as this guitar is what the measurements came from after the neck pull. They were close enough that they worked great. Now, with the measurements, one should be able to accurately place the probes. The other pic is the updated measurement pic which shows where I would now drill for probes. I feel that people are reluctant to use as much heat as necessary because of worry about finish damage. I ran some tests on old beater guitars as to when nitro starts to brown. Placed a heat lamp over a top. Browning on nitro didn’t start until about 270 degrees. I’ve read that nitro and poly won’t ignite until around 350. The softening heat of PVC and hide glues (liquid and hot) is around 150 per manufactures specs. So one can ( I do) heat the neck up to at least 200 degrees without fear of damaging finish. The heat on the outside of the heal gets up to about 130 degrees on the necks I’ve done (about ten at this point). These include all the so called toughies that consensus says are hard to remove (Yamaha red labels, Guilds, etc.) The thing about using probes is you can get heat directly to tight glue joints. When we hit the neck pocket, we are mostly heating a space. The probes are not in direct contact with most of the material we wish to heat and we are convecting instead of conducting. When we heat mostly the pocket (yes, a bit of the sides of the pocket and glue in pocket gets heated, but mostly through convection) we are also trying to heat more air (space) instead of conducting through direct contact with wood (yes, there are air pockets in wood fiber as well, but much less then the usual space we encounter in the joint pocket). So it takes much longer to heat just the pocket with only two probes, whereas heating the pocket in conjunction with heating the dovetail joints heats the neck, and joints we want to separate much quicker and more efficiently. The necks joints I’ve separated have proved this to me. So my humble take on the whole neck heating thing and the vid explains why I think using copper probes is far superior to steam and foam cutters.

[Tony Lewis Skypilot Guitar Repair]

And another thing (yawn)……..I noticed on all of the Yamaha red label necks of this style have truss rod anchors that twist into the wood notch See and blow up pic. Anchor has twisted counter clockwise a bit and dug into sides of notch). I suspect that simply capturing two sides of the anchor square are not sufficient. I twist the anchor plate back so the sides are parallel to the notch and then fill in the other two sides of the anchor notch of the anchor with whatever material the neck is made from (in this case Mahogany) to hopefully keep the anchor from twisting. I hope all this is of some help!

[Tony Lewis Skypilot Guitar Repair]

And further……..A couple of pics. One is a Yamaha red label twelve string. If memory serves, took about forty minutes to remove cleanly. Ironically, these two pics represent the two guitars Dave likes to work on…..unfortunately, I didn’t memorialize the measurements on the Yamaha. I will on the Harmony. I’m wondering if Dave has all the measurements. Would be a great addition to the neck data base.