Neck bending troubles

[John McDonald]

I'm having some trouble getting the neck right on this mid-60's harmony archtop. This is one of those all birch jobs with the steel reinforced neck but no truss rod. I do know that this neck was probably never "right" in the first place, but I'd like to see what can be done. It had the typical mediumish bow in the neck causing a hump in the fingerboard where the neck meets the body. With this set-up the guitar was fine playing open cowboy chords but would start to get buzzy by the time you would get to the 5th fret or so. I assumed this was do to the hump where the body meets fingerboard. I went ahead and tried out Hideo Kamimoto's neck bending technique. I carefully and slowly heated up the neck with a heat gun, put two hardwood shims on the fingerboard (1st fret and 15th fret) under a hardwood straight board, set up clamps in the middle of the neck and let it sit overnight. To my surprise, it actually worked!! I thought I was all set until I strung it up and realized that I had a perfectly straight neck with no relief. I hoped that string tension would cause a little neck relief but it didn't. This was no good for playability either. Begrudgingly fired the heat gun up again and followed Mr. Kamimoto's directions for bending relief back into the neck. This also worked but pretty much put me back to where I started. Plays great in open position but gets fret buzzy if you venture into the middle of the neck. I'm wondering if I can just grind down the frets a little lower in the "hump" area so that there is better clearance? Or should I try to bend the neck again? I also wanted to see if anyone has a better technique for bending warped necks. This method that I have been using seems to work but is not too friendly to plastic fret markers or faux painted fingerboards. Would an iron be better than the heatgun? 

[Ned Knepp]

I use a Bunsen burner which burns natural gas.  I  also have a small alcohol torch which works well. Both fuels burn pretty cleanly. The blade is dark but it mostly just discoloration from the heat.  One caveat to remember is that an open flame doesn't set well with fine wood dust or solvent fumes. I work in a well ventilated space anyway but I'm always careful to insure that I don't have any solvents open in the area and  I keep the sanding dust cleaned up.