Removing the HUGE rosewood bridgeplates

[David Houchens]

 While removing a bridgeplate (the BIG ones) I noticed the center seam opening up beneath where the bridge sits.

 I didn't heat my aluminum plate past 300 degrees and used another aluminum plate on the outter surface. Only left clamped for one minute at a time.

 Theres no finish problems from the heat although the seam did open beyond the bridge footprint a little in each direction.

 I have closed the separation by wetting and am ready to glue.

 OK, now my question. Is this a regular problem with the large plates?

 Do you see something I've done wrong?

 I've never had this problem before with narrow plates. The only large plates I've removed, the back was off already for other reasons.

[Paul Breen]

OK, now my question. Is this a regular problem with the large plates?

Other than pushing a tool through the top it is the most likely thing to create extra work due to the large area of applied heat to remove the plate.

I read in the Martin Forum where Bryan Kimsey cuts the plate into 3rds, parallel to the center seam and removes the center portion first. This technique helps limit heating time near the seam. I have been heating the whole thing at once and have also experienced some seam separation problems. I will be trying Bryan's method on the next one.

[David Houchens]

Thanks Paul. And Bryan. This sounds like it will help. I may also try a thinner chisel to cut down on the amount of preasure that pushes upward. Have to be a little more careful to keep flat to the top though.
I guess Bryan's saw has a depth stop like a fret saw to keep from cutting the spruce top if its a saw he uses.

[Rick Gentry]

I have heard Dan Erlewine say that he made a special saw to cut through the bridge plate. Does anyone have any idea what that saw looks like one of those short bladed jobs that clean out fret slots?

Frank, do you have a photo of one?

[Paul Breen]

I guess Bryan's saw has a depth stop like a fret saw to keep from cutting the spruce top if its a saw he uses.

There was no picture posted of the saw Bryan uses, I can only assume that there is a depth stop, seems too risky otherwise. The other problem is that the bridge plate butts up to the X brace leaving only a small area below the center of the X that a saw could cut past the edge of the plate. I think that a tool designed for this would be one that could be held outside of the sound hole, with mirrors lying inside, so you could start a groove in the plate and then keep it there.

I have been kicking around some ideas in my head but would love to see pictures of any solution others may have used.