Rebuild: Update 3

I've gotten a lot accomplished since the last post.

After shimming the bottom of the tenon, I needed to fix the angles of the other flat surfaces on the neck. I began first by making sure the flat joint surface on the body was as flat as could be. It should already be flat, but through the neck removal process, some material was removed and there were some cuts affecting the level. I used a file and a chisel to do this work. Not much was needed to be changed. I started filing the neck surfaces to bring the angle at the neck/body connection to zero (i.e. a flush seam). Doing so brought up a problem. The neck's curve as you move up away from the joint causes another curve to emerge as material is removed. This picture should help clear things up.

 The maple tenon shim is visible. The surface perpendicular to the tenon is being filed, removing most material from the top flat area. As the surface is filed (going into the picture), a curve emerges, shown next to the black line. 

This could be a problem if I were to continue. The connecting portion of the body wouldn't have the same curve. It would look goofy and would be hard to fix. Instead, I stopped adjusting the neck surfaces and added tiny shims on the body surface, shown below.

The body neck joint. Maple and walnut shims added to fill the areas created from changing the neck angle.

I glued the shims in and used the following method to bring the surfaces flush (from StewMac):

http://www.stewmac.com/freeinfo/Neck_relief,_building_and_repair/i-5763.html

The result is rather impressive, considering the size of the walnut shim.

Neck/body joint. The maple and walnut shims are visible. The seam is flush. The new binding will also help to make the seam even more fluid in transitioning to the neck.

With the neck angle fixed, I moved onto more barbaric repairs that needed to be addressed. These are, of course, removing the finish and binding. I don't have much on the finish removal process, but here are my steps.

For removing a nitrocellulose lacquer finish (expect binding damage):

1. Setup a work place with funky music playing and a chair in which to sit. 

2. Use a piece of cardboard as a work surface.

3. Obtain a can of Acetone from ye' locale hardware shoppe, along with plenty of spare rags, latex gloves (most other types will melt), and safety goggles.  

4. Place instrument on cardboard surface, and use your gloved index finger to regulate a dripping stream from the inverted can of Acetone onto the lacquer surface, making a reasonable puddle about 4" in diameter.

5. Wait 2 minutes, adding more drops in case the Acetone evaporates too quickly.

6. Use a folded rag to forcefully wipe the puddle up. If done properly, all the lacquer in the area should be removed, right down to the wood, in one wipe. 

7. Continue. I've found this to be the best method for the top surfaces.

8. For the sides, make a few attempts at the above method. It may work here and there, but most of the time it'll just run everywhere and you'll get frustrated and you'll go blame a relative for all the problems that have occurred in your life. I found just soaking the hell out of a small rag and wiping it down, repeating until all the wood is visible, works well for small surfaces.

It may not be the best, but it's what I did, and I got great results in under 6 hours of work over two days for just the body.

Finish removed, guitar naked. I've had a few people by now tell me to just stop messing with this guitar, it was fine before. I am, however, insane and have little else to do. 

As you can see, some binding has been removed. I have about 90% of the body binding off by now. It basically peels right off, with the exception of some areas tearing the side walnut off. I will have to fill those areas where this has occurred. I made sure all lacquer was removed where the binding meets the wood before trying to rip it off.

I will remove the rest of the binding and do some touch up work in the binding channel. This includes removing any binding glue (with acetone), squaring or rounding certain sections, and filling tear outs where they have occurred. By then it will be ready for new binding (StewMac 0.060"x0.25" cream). Until they are shipped, I will strip the neck lacquer and remove all the frets. After the new binding is installed, I can glue in the neck. 

That's all. 

Bye.

-A

Rebuild: Update 2

I began work on adjusting the neck tenon to achieve a proper neck angle. This was accomplished by manufacturing a precise wooden shim to place on the back side of the neck tenon. For the shim, I needed to use a hardwood to preserve the rigidity of the mortise/tenon connection. Since the tenon is mahogany and the mortise is maple, I would assume to use one of these. I chose to use some left over maple veneer for the shim. It was already thicknessed to 1/16", so all I'd need to do is taper a small piece that is profiled to the shape of the tenon. I did so against some sandpaper.

Maple shim tapered from 1/16" to 0", ~3" long.

To assure the shim brought the neck angle to the proper position, I loosely placed it under the tenon and used a C clamp to hold the neck in the mortise. I strung the high and low E strings to observe the action. Here's my setup:

C clamp temporary setup

The shim will need final shaping to assure the tenon and mortise sitting flush. Otherwise, the neck angle seems perfect. The bridge sits a little high, but I assume after applying full string tension, the neck will pull forward slightly and I can lower the bridge just a bit. It isn't hilariously high. Below are some pics.

Down neck view with new neck angle and action. Looking good so far.

The string elevation looks much better. The string angle from the bridge to the stopbar should apply more pressure to the body, increasing sustain and tone while reducing buzz at the bridge. 

Next step is to glue the shim to the tenon, use graphite coated paper to find high spots on the shim. After leveling the shim, I will tidy up the surrounding neck surfaces around the joint. It will be ready for gluing. Before this, however, I'll need to strip the finish and do binding work.

Updates soon.

-Mr. B