Poor bridge/top contact

[Uncle Choppy]

I recently bought a Lebeda F5. I was always aware that you could see a little bit of daylight at the edge of the bridge "feet" indicating an incomplete contact with the top (both bass and treble side). This can be seen by sliding some paper in the gap...

http://www.brendanashbrook.pwp.blueyonder.co.uk/bridge.jpg

My question is: should I be doing something about this?

I am not much of a handyman and would be very reluctant to start sanding down the bridge feet in case I make things worse. I have however read somewhere that there is a way you can attach sandpaper to the instrument's top (the thought makes me cringe!) and sand the bridge "in position" so that the base will follow the curve of the top perfectly.

My concern isn't tonal (it sounds OK to me) although I imagine that a better bridge/top contact can only be a good thing sound-wise.

What I am worried about is that all that downward pressure is being transmitted via a smaller area and that, in time, this might damage the top.

Brendan

[jim_n_virginia]

It's pretty simple really. This is what I do.

I get a grease pencil and mark where the bridge is. Usually just a few dots in front and the sides.

I take the strings and bridge off. I give everything a good cleaning because I don't take the bridge off often. Be careful not to clean your position marks off or you'll have to go through the trouble of finding the right position again for the bridge.

I get some blue painters tape and tape down all under where the bridge will go. Usually about 3 strips of tape 6 or 7 inches long.

I fold a corner of the tape under before pressing it all down so I don't have to scratch the finish with a fingernail trying to get a corner of the tape up. Your finger nail will cause pressure dents and I have first hand experience doing this unfortunately.

I then get a sheet of medium grit sand paper and cut it in fourths. You then put the sandpaper over where the bridge would be. And trim to fit so you'll have about an inch to slide the bridge.

Easy to see if you have F holes not so easy to get it exactly if you have an oval hole. If you have an oval hole you can mark with the grease pencil on the binding about where the bridge would go.

Now this part is pretty important but still easy if you take your time and go slow. Make sure you have the bridge facing the right way and you place on the top where it would normally go. And you gently slide the bridge on the sand paper up and down (not from the nut to the tail piece) being very careful you are holding the bridge perfectly straight up and down. Do not rock the bridge when you sand.

I never slide more than an inch (usually less)in either direction and you take just enough to clean the bottom. Remember you are only taking off the width of a piece of paper or so.

When you got the bridge where you want it. Pull off the tape gently being careful of your marks and then visually fit the bridge. You can get a small mag light and put it behind the bridge and see if any light comes through.

If you see light do it all over again and again being careful not to take off too much. If everything looks OK just restring and set the bridge to your marks and your done.

Now I will say only do this is you have complete confidence you can do it. If you are all thumbs or not a Do-it-yourselfer type then take it to a qualified Luthier.

If none are in your area I have read articles about using a small thin layer of sound putty on the bottom of the bridge to help make full contact across it although I have never tried it and not sure what it would do to your finish but if it is under the bridge who cares?

good luck! # http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif

[jaydee]

I can't tell from that angle, but it looks as though your bridge may be leaning forward a little bit. As you bring strings up to tension over and over again and retune etc., the bridge can begin to lean towards the nut, and the feet may even lift off of the top along the back edge of the bridge. If that's the case, just loosen the strings enough so that you can rock the bridge back,under gentle pressure, until it's perpendicular to the top again, then retune and you're done. Just to be on the safe side, check for that lean first before you do anything more drastic.

Jeremy

[Uncle Choppy]

Arrrgh - I can't believe what a half-wit I've been!

Thanks for the advice Jeremy - I've done what you said and the problem is gone (except for the tiniest bit of a gap, nothing like in the photo).

I had a slight issue with a leaning bridge on my previous mandolin, an Eastman. The difference was that it looked like it was leaning slightly - the Lebeda didn't. When I thought about it I was surprised that Lebeda would have such a poor fit, given the general high build quality.

Thanks also Jim for the comprehensive response. I'm going to keep those instructions as I can see myself picking up a cheaper oval hole, A-style at some point in the future and I might need to do the procedure on that.

Thanks everyone and sorry to Mr Lebeda for implying that his mandolins weren;t finished that well!

Brendan