Spline jig??

[Chris Rochow]

Somewhere I saw a jig, looked good, that allows ease in using a router to cut the groove in a broken (and glued) headstock, so as to insert a spline of wood. It made a nice straight and clean groove.

Anybody seen it??

Thanks!!

[Chris Rochow]

How else to make a straight & clean slot/groove for a spline??

[Paul Breen]

I don't know what you saw but this is a rig I came up with that is used in conjunction with a string tension simulation jig I built that was based upon the Stew MacDonald design.

The string simulation jig is used as a holding fixture for this process and the instrument strapped on face down. The actual plywood router jig is an "H" profile clamped onto the holding fixture's beam. A second strip of plywood is made with a stop and double stick taped to the plywood "H" as a stop that has been aligned where I want it. For this particular repair only one stop is required. The pictures explain this. The Cochran router base used was money well spent in my book and comes with an adjustable fence, the rig would have to be modified if you are counting on using the router's base against a fence or stop.

I thought I would just go ahead and show the before, process and after images as well since I had them. This is 68 (? been a few years since this was done) 12 string Rickenbacker. It had a couple of bad head stock breaks and repairs before it came to me. The break was almost parallel to the headstock and opening under string tension but I couldn't get the pieces apart without risking more damage nor effectively clean out the old glue so I opted for splines and a few carefully placed dowels.

BeforeThe jig rig.

I used two splines, there isn't much meat in these head stocks and it needed all of the help it could get. I also added some small dowels where they would be covered by the truss rod cover or tuners.

West System epoxy was used, this is high quality epoxy to which  I added some colloidal silica as a thicken agent. There was some voids to fill where wood was missing and the Colloidal Silica makes the epoxy stay put. Epoxy can have a really good chance of keeping any glue lines from telegraphing through the finish down the road.

A few pics after sanding.

The dark finish work has already been previously done so it was easy to hide my work under some fresh new darkness.

I think it's been 8 years since I did the work, the repair has, thankfully,  remained unchanged.

How about the tuner arrangement on this instrument? It is also strung with the octave to the bass E string reversed (on the outside) from how they are done these days. Ah, that 60's sound!

[Chris Rochow]

Paul that looks great!!   MANY thanks!  Where can I find a Cochran router base? Does  the base adjust for the back bend in the neck? And adjust to "side to side" for making two passes for two grooves?

[Paul Breen]

Here is the link

http://www.bishopcochran.com/

Does  the base adjust for the back bend in the neck?

Not sure what you mean by that. The base has a fine screw adjustment for up and down and comes with a fence attachment for side to side adjustments. The way I plow the groove, the cut is flat, entering from the headstock and ending deeper into the neck. Great care must be taken to not go too deep and get into the truss rod.

[Kerry Krishna]

Paul that is an amazing finished job on the Ricki! Man, that looks nice!!!

[Chris Rochow]

Thank you!  Great job!     My Porter-Cable router has a plunge feature that I can use...and it is adjustable to pre-set depth.  Should work fine.

 

Wonderful pictures too!  I think I should have no problem making this jig.

Again, MANY thanks!!!

[Paul Breen]

Thanks Kerry!

Your welcome Chris, good luck with the work.

I used to take a lot more process pictures than I do now. It takes time to do good photography and I don't seem to have a lot of that lately.

[John]

I used to use the spline approach, saw it in a book that said it was the way Gibson did it. The last few years I've been using the Ernie King method, Ernie King owned a Music Store in Wingham Ont. he was a local television personality and great guitar repairman.

The idea is to put fresh wood across the crack.Wood is scooped out using the end of a belt sander (you could use a drill press drum sander) and a new piece is fit into the scoop and then shaped to the neck. Use chalk or just rub the new piece back and forth in the scoop to shape the new piece.

An alternative method is to glue up pieces of veneer until you're proud of the neck profile then shape to match the neck. I use surgical tubing to clamp the veneer pieces, I do them one layer at a time and precut them to the outline of the scoop. I'm not the best at documenting my work but here are a few examples. The last one is a repair to the front of the headstock I inlaid a book matched piece of walnut inside the binding. Although it added some strength it was largely an aesthetic repair. 

[Kerry Krishna]

     John, I really had to look twice to see that the curve on the front of the Garrison headstock was not original. Man, it REALLY works! Great job on that.

    

[John]

I think I used a coffee can to draw the curve.