I've had fun scanning some of the cheap Chinese sites in search of practical gadgets. It always takes a week or two for packages to arrive from China, if you're going to buy cheap it's much faster and safer with Swedish Amazon which has many interesting gadgets for a guitar repairman. I will report several of my findings, but this one the neck jig for straightening bent guitar necks was very good. It is solidly built in black anodized quality aluminum and with a suitable ssilicone heating blanketPreviously, I made my own jig relatively quickly with clamps, a caul, an aluminum plate and two travel irons, but this jig can be assembled much easier, faster and safer.

I had the opportunity to test it out at a flea market find that my buddy Mattias had bought. A cheap German parlor from the late 1950s in good condition, but with a bent neck. It worked very well. The fretboard was saturated with thick teak oil to reduce the risk of the fretboard shrinking in width. The neck was bent to a catback curvature as large as the relief the neck had before with the center screw in the jig, sthe silikon heating blanket was heated to about 80-90 degrees C. I double-checked the temperature and it matched the numbers on the knob. I had to replace the English wall plug with a standard 220 V European plug. It heated the fretboard and neck for about 30 minutes before I turned off the heat. The next day the guitar was removed from the jig and the neck was straight as a spear 🙂

Two plastic accordion dots in the fingerboard had been boiled and were replaced with real mother-of-pearl, but as the silicone heat blanket is narrower than the fretboard, the fretboard did not shrink much, the fret ends only needed a light filing on the tops and there was no sharp edge between the fretboard and neck. Since the silicone heat blanket is narrower than the fretboard, the fretboard had not shrunk much, the fret ends only needed a light filing on the tops and there was no sharp edge between the fretboard and neck.

There are two things to watch out for when doing this kind of heating. First, the fretboard can shrink in width due to drying out, and second, the varnish under the caul can either get pressure damage from the caul or the varnish can even stick to it. If you have a neck with a heat-sensitive varnish, you should reduce the temperature to about 60-70 degrees C and instead extend the heating time. The surface of the caul should be as smooth as possible to avoid pressure damage to the varnish (the caul in this jig has a dense and fine felt) and you should put household plastic between the caul and the varnish as a release agent. You can heat it a maximum of two times, then the neck becomes so stiff that it no longer wants to bend. If you can get the first heating right, a lot has been achieved.