How To Repair The Neck Joint On A Vintage Harmony Guitar

Acoustic Guitar Cervix Reset

Pace 1: Loosening The Fingerboard Extension

Earlier removal of the neck begins the portion of the fingerboard which glues to the elevation must be loosened.

heating fingerboard extension
Estrus is applied to soften glue beneath the small
area of fingerboard that overhangs the top.

I personally use a specially designed heating "blanket" which is similar in size to the fingerboard's extension. This allows me to oestrus simply this part of the fingerboard without heating the surrounding end.

Before the days of handy sized heating blankets I used a traditional clothes fe. This required shielding the instrument's top from the heat to avoid baking lacquer and other vulnerable finishes.

With the glue soft from heating I utilise a smooth spatula to slide between the fingerboard and top. Using a smooth, even polished spatula insures the finish around the fingerboard is not scratched. When the end is fragile I employ low tack, newspaper tape to protect information technology. (Think Post-Information technology® sticky) On vintage instruments with flakey finishes it can actually come up in handy.

Step 2: Steaming The Neck Loose

With the fingerboard still hot I remove the fret which lies directly above the dovetail pocket. On nearly all instruments this is one fret upwardly from where the neck meets the torso, this is unremarkably the 15th fret.

With this fret removed I can now drill a hole straight thru the fret slot which volition lead directly into the pocket. This serves to avoid whatever visible signs or changes to the fingerboard that would bespeak a repair had been washed.

Drilling a hole thru the fret slot helps to avert whatever obvious modify to the instrument.

steaming neck loose

Steam is injected into the neck block to soften the mucilage. Instruments with loose necks may let steam to escape effectually the heel of the neck. When this is an issue I use an air hose to accident steam away from the surface area, keeping it dry and cool.

Some truss rod nuts are accessible beneath the fingerboard extension, every bit a result steam volition likewise find information technology's fashion out thru the truss rod hole and care must be taken to plug the hole and protect the interior of the instrument.

Steaming usually takes but a few moments. In all simply a few instruments water soluble gum is used. Because a well fit dovetail is relatively tight, very footling glue is between the dovetail and sides of the neck block.

Step three: Removing The Neck

removing neck from body
Pushing the cervix free from the body.

As the gum is softened the cervix begins to move with effort.As separation becomes apparent I apply pressure level to the heel cap to press the cervix out of the block. When the fit is very tight I use what I call my "sissy jig". It'south a real life saver when my bionic thumb can't do the job.

Step 4:Changing The Necks Angle

Once the neck and joint have dried and erstwhile gum is removed the neck'southward angle is inverse by shaving material from the heel.

I use chisels to remove the majority of wood, followed by sanding sticks when necessary.

chiseling neck heel angle
A new taper of the heel's sides will increase the neck angle.

When string height has risen due to an increase in the top's arch (belly) material is removed from the lesser portion of the heel, tapering gently to the top of the heel (below the fingerboard). With the instrument lying on it'due south back this aligning would pitch the cervix back, placing the peghead closer to the demote.

Wood is removed in very small increments, the cervix placed back in the pocket to recheck it'due south angle, rinse and echo...

As detailed in my article on cervix bending nosotros are adjusting the necks angle to insure it's plane passes over the bridge.

straightedge hitting below bridge

While shaving wood from each side of the heel, the side to side pitch of the cervix is likewise closely watched. Removing more wood from one side than the other would identify the outer E strings unequally from the border of the fingerboard.

Ideally the center of the fingerboard should run right between the D and G bridge pin holes. When dealing with vintage instruments information technology is not uncommon to notice that the span is not expressionless center on the top, so to avoid an outcome the neck is centered using the bridge, non the height's center mucilage seam.

Step 5: Shimming The Neck Block

After adjusting the neck'due south side to side bending and it's pitch, shims are used to lock the dovetail in place.

I glue mahogany shims to the sides of the neck block and start the procedure of fitting the actual dovetail, that which "locks" the neck in place. The shims are sanded to insure an even fit from pinnacle to bottom of the heel.

A well fit dovetail volition hold a neck in place before glue is fifty-fifty applied.

At this indicate all angles are re-checked to insure nothing has been overlooked.

Step 6: Re-gluing The Neck

The easiest part of the job ...gluing the cervix dorsum in identify. Titebond Regular is applied to the sides of the dovetail joint and beneath the fingerboard extension.

Clamps are used above the dovetail and over the fingerboard to insure complete seating of the articulation.

gluing neck onto body
Gluing the neck back on a Martin guitar.

The Grand Finale

Titebond (and other aliphatic glues) are water soluble. This permitted the neck to exist removed with steam. It also makes clean upwards relatively like shooting fish in a barrel as well. Warm water volition clean upwards dried gum that has squeezed out during clamping.

Now that the angle of the neck has changed the fingerboard is now bending slightly downward to make contact with the top. For a truly professional job the fingerboard is planed directly and re-fretted. The tiny holes drilled below the 15th fret filled and at present a distant memory.

Due to the changes in the neck'due south angle, the musical instrument's saddle and nut may need to be replaced during the fix.

Cost

Cervix resets are not often performed on inexpensive instruments for the simple reason that they can actually be replaced cheaper than they cost to repair.

Cervix resetting a dovetail joint like the ane detailed above kickoff at $650.