Neck Press for Guitars With Dowel Joint Neck Attachment

Less expensive acoustic guitars are often built with doweled neck joints, as opposed to a dovetail joint, mortise and tenon joint, or a bolt on arrangement. When guitars that have either a dovetail joint or mortise and tenon joint need a neck reset (adjustment of the angle of the neck relative to the body to restore play-ability), the neck is loosened with steam or other heating methods, and pressure is applied to the bottom of the heel of the guitar neck to push the neck up from the guitar body. The neck press tool used for these style guitars does not work for guitars with doweled neck joints. The neck press shown here pushes against the end of the fingerboard so the pressure is applied in the direction parallel to the dowel pins.

It can be argued the guitars with doweled neck joints are not built to be repaired once the neck angle has degraded. Its not my purpose to argue the economics of repairing less expensive guitars, because in most cases the cost to have a neck reset done at a guitar repair shop will exceed the value of an inexpensive guitar. The neck press design I show would be useful in cases where the instrument had significant sentimental value, and repair cost was not an issue. It is much less invasive than sawing off the neck with a flush cut saw, but there are some additional steps when removing and resetting a doweled neck that add time and effort, so that should be considered as well.

One of those considerations is that less expensive guitars are usually finished with the neck on the body as opposed to separately. The manufacturer typically allows the finish to build up between the neck and body, and the fingerboard extension and top. These joints must be heavily scored until the finish is no longer "gluing" the neck to the body.

To use this neck press, the finger board extension needs to be released from the top of the guitar body first as with any neck reset. Once the fingerboard extension is free, the steam holes can be drilled.

The materials used in the neck press are:

~ 2ft 1x2 pine

1/4" plywood

1/4 - 20 threaded rod

1/4 - 20 blind nuts

1/4 - 20 threaded knobs

1/4 - 20 carriage bolt

assorted dry wall screws and waterproof glue

Some guitars will have neck heels made of 2 or more pieces of wood. Because the doweled neck press exerts a pushing as well as a torquing force, it is necessary to drill steam holes on the bottom of the neck as well as through the fret board. Without this precaution, it is possible for the top of the neck joint to release, but have the neck heel crack right above the lowest dowel pin. With careful placement and sizing of the steam holes, the holes usually disappear once material is removed from the bottom of the neck heel during the reset process.

The placement of the steam injection holes on the neck heel is not critical. The idea is to place them on either side of the lowest dowel pin, but not so close to the edge of the neck that the steam escapes there before heating the dowel pin.

Similarly, the steam holes drilled through the fingerboard are placed between the upper dowel pins and the truss rod, getting as close to the center of the neck as possible so the steam can reach the dowels in the center of the neck joint.

Begin by injecting steam into the bottom of the neck heel. There will not be any joint separation, but the glue holding the dowel pin will be sufficiently weakened to prevent cracking off the bottom of the neck heel in most cases. Then inject steam through the fingerboard steam holes as usual. You may want to alternate between the fingerboard and neck heel steam holes a few times for added insurance.

I've successfully reset 6 guitars with doweled neck joint using this neck press. Dowel pins that stay in the neck rather than in the guitar neck block should be removed to make it easier to remove material from the neck during the reset. There is often a small amount of swelling on the guitar body after the parts have dried from steaming which requires making the mating neck surface slightly concave so the neck joint is tight. Once you have removed material from the neck, you may also find that finish along the edge of the neck that is "piled" up on the surface of the guitar body interferes with the neck fitting tightly to the body, and must be carefully trimmed back. If there are any chips in the finish of the neck or guitar body, they are much easier to touch up while the parts are separate, and then no additional finish work is required after the neck is re-glued to the guitar body.

The parts dimensions are not critical. These pictures of the neck press show the threaded knobs I've added to make using the neck press easier.