Before we take the neck off the 0-18T for the reset, we need two more important measurements. You may recall we already measured the distance a straightedge laid on the frets falls below the bridge.
The next measurement we need is the height of the neck heel. You can see me capturing that measurement here.
If you can read the maths I did on the left (click and it's larger...), or you can find the formula elsewhere.
Now we know we need to remove .040 of an inch to have the correct angle.
Now we can remove the neck.
First step is to remove the fret that is above the dovetail. In this case, it's the 15th fret. We heat it up a bit with a soldering iron.
This guitar was made in 1931. Martin didn't start using T-frets until about 1934. My other 1931 model has bar frets, but this one has T-frets.
I suspect that these are not the original frets. But whoever did the refretting did a great job.
I have a homebrew body protector - foil over cardboard - that I use to protect the body from heat during this process.
This guitar's fingerboard is a bit narrower than my template's opening, so I put some extra foil on the shoulders of the guitar.
There's foil over the extension itself so the wood won't scorch. And notice that I also heat my removal knife under the iron.
Then I'm able to gradually slide the removal spatula into the joint.
The old glue is hide glue, which separates pretty easily with heat.
Take your time and don't force the knife. When you have resistance, put all of the foil back on and heat the joint some more.
I just saw a Dan Erlewine video where he separates a whole fingerboard using this method - and he used two knives - one on top of the other to help protect the wood. I'll try that next time.
I have a long (6 inch I think) thin drill bit for this job. Be sure to put a flag on the bit so you don't go too deep!
The idea is to hit the side of the dovetail. It's always a bit of a guess unless it's the same type of instrument you've done before and know exactly where the side of the dovetail is.
I was a bit too far toward the center on this one as it turned out. But the joint still came apart ok.
You can see the steamer hose attached to the machine on the left side.
We apply steam and crank the screw handle a tiny bit...tiny bit...until the neck releases.
In practice, I've found that the neck can be jiggled side to side as the steam loosens the glue. Sometimes that motion is enough to release the neck.
There is a bit of water along with the steam, so I have clean rags there to catch it.
I usually apply the steam for maybe 15 seconds at a time and test the joint. It will take a few minutes to get the joint loose.
Don't force it! Depending on the guitar, there could be a lot of glue in the joint (e.g. Guilds). Usually Martins pop right off, but this one took a bit longer than usual.
It does seem as though this guitar had a bit more glue than usual in the joint.
You can hit the dovetail with a touch more steam if needed.
It's actually finish 'blush.' Moisture is trapped under the lacquer.
Do not panic if you see this! It's easily corrected.
Let it harden for a couple of days and then it can be polished. It will look perfect afterwards.
Now we can go about trimming the neck heel for the actual reset.
All posts in the 1931 Martin 0-18T Restoration Project:
- 1931 Martin 0-18T Guitar Restoration and Repair, Pt. 1
- Neck Removal on 1931 Martin 0-18T Guitar: Restoration and Repair, Pt. 2 - This page.
- Trimming the Neck Heel for Reset: 1931 Martin 0-18T Restoration and Repair, Pt. 3
- Shimming Guitar Neck Dovetail and Finish Chip Repair: 1931 Martin 0-18T Restoration and Repair, Pt. 4
- Caul for Heat-straightening Guitar Neck: 1931 Martin 0-18T Restoration and Repair, Pt. 5
- Reparing Acoustic Body Cracks: 1931 Martin 0-18T Restoration and Repair, Pt. 6
- Making a Tortoloid Pickguard: 1931 Martin 0-18T Restoration and Repair, Pt. 7
- Heat Straightening Bowed Guitar Neck: 1931 Martin 0-18T Restoration and Repair, Pt. 8
- Fret Marker Installation and Filling Fingerboard Chips: 1931 Martin 0-18T Restoration and Repair, Pt. 9
- Compression Fretting to Correct Upbow: 1931 Martin 0-18T Restoration and Repair, Pt. 10
- Completed 1931 Martin 0-18T: Restoration and Repair, Pt. 11