This neck repair on a Martin acoustic guitar was necessary because the owner had stored the guitar in his garage, in its case with strings on for a couple of years.
When he got it out to use it, the action was sitting at around 5mm at the 12th fret.
He knew the neck had moved because the heal joint had opened up as the tension on the strings pulled at it over the last 2-3 years, combined with temperature fluctuations that you would expect in a garage.
I see issues with acoustic guitars drying out more frequently than ever but usually due to them sitting in centrally heated homes causing them to dry out.
On this Martin 000-15 Acoustic guitar we were fortunate that there was practically no deformation of the guitar body so the top face hadn’t “bellyed up” causing it and the bridge to pull up.
There was enough of a gap between the heal of the guitar and the body to allow me to prise it open gently and just enough to allow me to run some Titebond adhesive into the gap. Moving the neck back and forth creates a slight suction force that helps suck the adhesive into the joint. After repeating this a few times I was happy that there was sufficient glue in the joint to hold it in place once I got the neck pulled back into shape/position.
So, how did I get the neck back into shape to allow the heal joint to fully close up?
Firstly I piut a small trickle of steam into the body of the guitar, through the soundhole having 1st covered the soundhole with a plastic cover. This re-humidifies the tonewoods of the body, making the body more pliable and less prone to crack.
I did this before glueing up the neck joint by the way.
You need to know what you’re doing with the steam otherwise you can pop off the bracing inside the guitar.
After steaming and glueing up the neck joint, I put a damp cloth inside a plastic dish inside the guitar body, covered it up and then strapped the guitar body onto a clamping jig that I made up for jobs like this. The damp cloth indide the body continues to add some moisture into the guitar body while it sits in the jig.
Then I tightened a ratchet strap around the neck of the guitar to pull the heal joint tightly closed. Again care is needed here so that the fretboard isn’t pulled off the top face of the guitar.
The guitar will now sit in this jig for a couple of days.
The photo looks like the guitar is being treated quite brutally but it isn’t as bad as it looks and the conditions are kept under tight control and review.
Sometimes it’s better not to let clients see their instruments in the workshop because often the old adage “you have to be cruel to be kind” rings true.