A Bridge Fitting Question

[crawdad]

I have read the accounts of how to sand the bridge to match the top. However, due to the deflection that occurs when the instrument is strung up to pitch, the top radius is different. If I take the strings off and match the bridge to the top without string pressure, its going to change when its restrung to pitch. In short, my top is changing slightly when under string pressure. What do I do? I'm rather hesitant to apply hand pressure to the top for fear of breaking it. Its damn close now--a few thousandsths and no light will get through. Should I leave well enough alone, or is there a technique I can use to get it absolutely perfect?

[Yonkle]

Hi Crawdaddy-O: I had this problem on mandolin #2. The light gap is probably right on the ends of the bridge...correct?
Mine did this, and I think it may be the string presure pushing so hard in the middle of the bridge it brings the ends of the bridge up a hair.
I just slid my strings off to the side of the neck and sanded the bridge down a little more, put the strings back in the slots and tuned up again and played it a few more days and checked again. After a few days the second time the gap closed up.
I guess you just keep sanding is the answer.. #JD

[Michael Lewis]

There is considerable stress in the bridge/top connection, and as Yonkle mentioned, let it be for a couple of days. These parts tend to form to each other over time. If they are as close as you say, they should close up in a while. If there is more gap than stated you will need to fit it better. Just take material off the bottom of the bridge foot where it contacts the top when under tension. Unfortunately this will be a "cut and try" situation.