Official Luthiers Forum!

There is an excellent article on bridge removal/regluing written by Rick in Acoustic Guitar this month!

Way-to-go Rick!

Thanks, Hesh. Haven't seen it. If there are photos I took, that's my fave Howe Orme that I put the bridge back onto. Note the cylinder arched top...

I just got my issue and read the article. So what exactly is the radius on the top of that guitar?

I particularly like the special tool you devised for removal. For those who haven't seen this, that tool is described as "a thin blade with rounded tip that is sharpened on 3 edges".

BTW...I've heard of a technique where the bridge is removed by striking a side with a sharp blow from a hammer and piece of wood. It sounds scary and somewhat risky to me. Any comments on the technique?

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JJ
Napa, CA
http://www.DonohueGuitars.com

The bridge removal tool is like a thin wide oyster knife that can be rocked sideways and eased into the glue joint.

The technique you're referring to is with a hammer and a chisel, and it's to be found in the old Martin repair manual. It's probably only good with hot hide glued bridges; I think that Titebonded or LMI glued bridges would come off with a lot of top if you did that. The idea behind it is that you essentially shock the glue line in shear I've never had the cojones to try it.

With modern methods of using heat, either from a heat lamp (top well protected...) or with a small heat blanket, softening the glue line is much safer than the "don't force that, use a bigger hammer" method.

The radius on the guitar top?   Well, it's not quite like   you might expect.   The center third or so of the top is cylindrically arched, and the radius of the cylinder before it recurves back to the "flat" areas of the top is probably around 18".    Yes, inches... It's incredibly light and strong, and that guitar sounds fantastic.

I recently had an opportunity to try the "sharp blow" technique on a guitar that was getting a new top anyway.  I used a knife (one kind of like what Rick describes) to go in cold about 1/8" all the way around.  It was glued with titebond and it took a surprisingly hard whack to get it to pop and it took some top wood with it, but not much.  Not something I'll be trying on a top I want to keep.  But I recall a post in the MIMF archives of Charlie Hoffman talking about using that technique.  I think he says that's their regular procedure at the shop!  If there's a learning curve to it, I don't know how you get around the first bend.

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http://www.chassonguitars.com