i have more experience with these pieces than i care to remember.
first, i need to ask, and you need to ask yourself, does the fingerboard really need to be removed? is it unworkable ?
are you removing it for a repair when you could possibly work around it, or drill through it and plug it after ?
if it must come off, i have a couple of methods that may work
forget about heating blankets & alcohol. that's like trying to pee on a forest fire.
i know this may seem redundant or pointless, but i always try the simplest thing first.
method 1) hold the palm of your left hand on the back of the neck, about midway, and place your right hand, palm down, making kind of a "spider" with your fingertips, on the belly of the beast, between the belly & the fingerboard, about midway between the heel of the neck & the end of the fingerboard.
now, simultaneously, push up with your right hand, using fingers, wrist, & forearm, while pushing the neck into the heel with your left hand, using an equally oposing force, so as not to pry the neck out of the mortise, or to break the neck.
in most cases, this will break the glue joint, and then you can work in knives and/or solvents as necesarry.
metod 2) sometimes, actually most times, good to use this in conjunction with method 1.
get a good chisel, at least 1" wide, sharpened @ about a 35' angle, with no micro bevel. very carefully, find the joint, BEHIND the nut, where the nut is glued to the neck. position the chisel, bevel side down (towards the neck) and rap it relly good with a nice heavy mallet. the nut should break loose after 1 or 2, maybe 3 good strikes. if you break the nut, no big deal. its a nut.
if you mar the neck slightly, it will only be behind the nut, in the pegbox. use your touch up pens.
once the nut is removed, carefully position the chisel, again, bevel side down, at the seam where the fingerboard meets the neck, where the nut would join the neck & fingerboard, and rap the chisel with your mallet. if nothing gives after 2 or 3 blows, you need to quit before causing any damage.
most likely, the fingerboards are glue on with C.A. stuff, and the only solvent that will work is acetone. unfortunately, acetone will destroy any finish except for pollyester. yes, the same stuff that is melted and drawn into a fine thread, and then woven with cotton thread to make that shirt you're wearing.
again, i think you're better off finding a way to do what you have to do without removing the fingerboard.
hope this helps. if you have any more ??s, email me:
[email protected]
smg.