Radiusing the bridge before gluing.

[johnnparchem]

I know this discussion occurred in a previous thread and it is very much related to a current thread on top radius.
I am about to glue the bridge onto my classical guitar so I built a 25' radius sanding board to put the radius on the back of the bridge. I know there was a discussion about gluing it flat or radiusing it on the top itself to match the built radius on the top. I thought this through and decided to treat the bridge as any other brace and put a complementary radius on the bridge to match the 25' radius I put on the the fan bracing, and the radius of the solera I work in. I realize that I am using a cylindrical radius instead of a dome.
I was hoping to find the old thread that discussed radiusing the bridge before gluing but was not successful in my search. I would love to hear any different opinions

[kencierp]

John I think what you've done so fair should work great -- However, I doubt that the fan bracing has retained much of the contour, so I would suggest that you true up the glue surface using the guitar as a form as shown below. I am not a big fan of doming the top of a classic since the string tension really tends to yank a natural bulge into the thin lightly braced soundboard.

http://www.kennethmichaelguitars.com/bridgeprep.html

[johnnparchem]

Thanks Ken,

You are correct that the fan braces do not hold the dome, thus my thought about reinforcing it with the bridge. Thanks for the reminder that the string tension pulls a dome on a lightly braced classical. I think I will switch to the method you show. Than is what I did on my last classical guitar.

John

[Tony_in_NYC]

Using the domed dish like you have let's you get the bridge contoured faster. I have one too but I always finish up on the guitar.

[Ben-Had]

Using the domed dish like you have let's you get the bridge contoured faster. I have one too but I always finish up on the guitar.

+1 and DITTO. Always works great for me that way.

[Tony_in_NYC]

See? Tim knows the deal.

[ColestineGuitar]

This is an interesting thread. I saw a video online where a luthier made a reverse version of his radius dish (using fixall or water putty) and used that convex surface as a sanding block for his bridge. But now I see that you should still finish up on the actual guitar top.

Don't believe everything you see on the internet.