On 5/26/2015 3:00 PM, oldtools-request@s... wrote:
> Subject: Re: [OldTools] How to remove all finish from mahogany veneer 
> Message-ID: <5564269F.3090901@p...> Content-Type: 
> text/plain; charset=windows-1252; format=flowed Ed Minch wrote:
>> >For guitar disassembly, many use a chef?s icing spreading knife - very thin
and just the right shape.  I have found 2 of these at gar(b)age sales.
>> >
>> >http://cooksdrea
m.com/store/product/ca/a1375.html

Many years ago I found an ideal blade for separating glue joints. It was 
a thin knife, about 12" long and about an inch wide that was originally 
used in a carpet mill machine to cut the threads that made up the 
carpet. Evidently, these blades were replaced frequently and were quite 
common. Don't know about now. Anyway, it was just the right thickness 
and flexibility for the job.

As for taking bridges off by breaking the joint with a sharp blow, I 
have my reservations. I'd heard of this technique years ago from some 
respected repair people, who had tried it for a while, but had gone back 
to the traditional method because they had had one too many disasters. 
On a vintage instrument, one is too many. The original rationale for 
avoiding heat was that heat could compromise the center joint, the 
braces, or the bridge pad. However, careful and judicious application of 
heat has presented no problems for me, at least to date. Knock wood.

In addition, unless one knows for certain that the bridge was glued with 
hot hide, trying to shear the joint with a sharp blow may easily destroy 
a top. Titebond and epoxy, for example, do not lend themselves to this 
method. Even hot hide can be amazingly stubborn to remove. The most 
difficult neck reset I ever tackled was on a Schmidt and Maul parlour. 
This guitar was in the neighborhood of 125 years old and had been 
"stored" in an unheated attic for over 60 years. It took many hours of 
careful steaming and wiggling to finally get it loose. I would never 
have risked trying to knock the bridge off that guitar! If there is a 
trick to loosening hide glue, it is patience, not brute force.

Likewise, using alcohol to soften glue. Alcohol can be another disaster 
if the finish is at all alcohol soluble. I'd recommend warm water and if 
necessary, maybe vinegar.