My Gibson J-40 repair experience (a bit long)

[David Burns]

My%20Gibson%20J%2040%20repair%20experience.doc

Howdy Folks,

 

This is my first post here,

 

I worked at Gryphon Strings for a year in the 90's which is how I came to know Frank Ford and eventually this website. When a friend gave me a 1972 Gibson J-40 with multiple repair issues I figured I'd start researching for repair info here first. Here were the two main problems:

1) The bridge was not glued to the soundboard.

2) The frets were badly worn.

 

The nut and saddle were also missing so there was lots of work ahead for sure. I'm not a professional repairman but I had done a refret on a Kramer electric guitar and had done several fret levels and restored a few "garage-sale" prizes so I had some of the tool and basic skills I needed.

 

After looking for info on the net about the J-40 and saw several for sale on Ebay I realised this was not a super collectable Gibson that lots of people were looking for so I decided I'd give the repairs a go. ! spent about $80.00 getting some additional tools from StewMac like the clamps for clamping the bridge and a 10" radius sanding block.

I've documented relevant portions of the repairs that I thought might be useful. Sorry If you don't have MS Word, I could post more pictures here if requested. I'm more of a Martin than a Gibson man but I must say this J-40 is one of the best sounding Gibsons new or old I have played. That was a nice surprise.

 

After all this work and playing the guitar a few weeks two problems still remain:

1) The neck needs to be reset   2) The bass side of the saddle is slightly more forward than it should be.

 

Two Questions for you all...

1) Is this model of guitar one that someone with intermediate woodworking skills could tackle a neck reset or should I yield way to an experienced repairman?  (I think I know the answer already; just checking)

2) What would you reccomend as a repair for the saddle positioning: a) a wider saddle to give room for compensation or b) fill the old slot and cut a new one with the proper dimensions?

 

Thank You for any insight you may provide,

 

David Burns

[Eric Steven Johansen]

In answer to you're first question, Gibson neck resets can prove to be quite challenging due to the fact that they glue the entire joint, including the butt of the heal to the sides, so steaming takes more time than normal, and lots of patience. I'd give it to a pro. As far as the saddle is concerned you might first try cutting the bass side as close to the back of the slot as possible (new saddle probably) to see if intonation can be corrected. 

[David Burns]

 

1) There's alot of finish where the neck join's the body too...

2) The bass side of the saddle is off by .065" so there's not enough width in the saddle to compensate that much but I could get a small bit...

[Len Biglin]

It sounds like the action is high due to neck angle , that will throw the intonation out and it may be ok after the reset .

[David Burns]

Hmmmm... that's very insightful... thanks!

[Eric Steven Johansen]

Len is correct that a reset may correct the intonation problem. The finish on these guitars is applied after the neck is set, grrrrrrrrrrr. Just one more reason to call in the pro.

[Dave Richard]

I have worked on two 1970-ish J-40s, including neck removal. On one, the top had been glued over the dovetail(underneath the fingerboard). Surprise! On the second, the dovetail was straight, not tapered...hence, it did not 'pop' free once the glue softened, but had to be dragged all the way out. Surprise! But they have little or no value, so they're perfect for learning repair techniques.

[Eric Steven Johansen]

In todays market this "Smiling Face" Gibson is worth about $800 in perfect condition.

[David Burns]

"the top had been glued over the dovetail(underneath the fingerboard"

Dang! How did you figure that out without removing the entire fingerboard?

I just looked inside my J-40 and it looks like the top wood goes over the neck-block but how do you tell if it covers the dovetail or not?     

 

I looked closely at the neck joint with some magnifiers and it looks like the finish is checked all around the joint so I think it could be scored with a sharp blade without too much problem...

 

I think I'd like to try doing the reset myself... but having the top covering the neck joint, wow... I'd be really intrigued to find out how you solved that puzzle....

[Dave Richard]

I don!t think one can tell, by just looking, if the top is over the dovetail. I discovered it, while steaming to remove the neck. It would not come off, so, reluctantly, I cut through and removed the fingerboard extension. Then, I could see it. When I did the second J-40, and the neck would not come off, I again removed the fingerboard extension...no top over the dovetail, but it was a straight dovetail. Gibson management made many awful and inconsistant production decisions in that period. Yours may be a standard dovetail...
Both of the guitars I worked on were in poor shape. Eric, I' m surprised they're worth that much.
David, I still think it's a good one to learn on. You're now aware of what might be there. It would be good to use one of the 'Stew-Mac' style neck presses, to aid in the removal, while steaming.

[Eric Steven Johansen]

Surprisingly the early 70's Gibsons have been gaining some ground in the vintage market, I guess due to the price of a 60's version. My humble opinion is that I wouldn't pay that due to the 3/8" thick plywood bridge plate, the double X-brace, and the general poor quality of the instruments, but collectors see things a bit differently I guess. I too have encountered the buried dovetail on two Gibsons so far, so my modes operandi is if it refuses to move fairly quickly while steaming I'll remove the entire board before proceeding. Better safe than sorry. 

[David Burns]

"It would be good to use one of the 'Stew-Mac' style neck presses, to aid in the removal, while steaming"

 

That's a good idea... a question about steaming the neck joint....

I notice that some fret after the fret where the neck and body meet then drill a small hole to insert the needle for injecting the steam into the joint...

On my guitar someone has installed a strap button on the bottom of the heel of the neck.

What do you think of the idea of using the strap button screw hole to inject the steam into by extending the hole till it enters the neck joint then using that hole to route the steam into?

[Eric Steven Johansen]

The normal procedure involves removing the 15th fret and drilling two holes, one at each corner of the back of the dovetail. The reason for two holes is to give the steam a place to escape so you don't over saturate the head block. Entering through the bottom of the heel will never get you cleanly into the joint IMHO.