gap between fingerboard extension and body

[JLT]

I've been working on a guitar that somebody else started and gave up on. The soundboard is perfectly flat in the area north of the soundhole. I've set the neck angle at 1.5 degrees, and have found that (not surprisingly) there's a gap between the fingerboard extension and the soundboard that exactly reflects this 1.5 degrees. After reading what's available on the forum, I gather that the accepted thing is to ignore it, counting on the bow-down of the fingerboard to compensate for it (the bow-down being caused by the installation of the fingerboard extension frets). However, I'm wondering if it wouldn't be better to cut a shim with a 1.5 degree angle and slip this under the fingerboard extension to ensure a more positive mating of the surfaces.

Should I do this, or just glue the fingerboard extension down and accept the bow-down and curve of the fretboard in that area? What are the downsides of each way of doing this?

[darren]

Is this a kit? If so who's kit is it? you should follow the directions for that supplier.. that being said a gap is not acceptable and you probably shouldn't ignore it. John and others can help you with the numbers but there are some things we'd need to know first:


what is the angle of your neck heel?
is the gap at the end of the fb or at the neck joint? how much of a gap are we talking about? pictures help.
what is the height of a straight edge held on your fretboard extending over the body, at the bridge location?

[penndan]

dog
I faced the same problem while building/assembling a Beard reso kit.
viewtopic.php?f=48&t=5557&start=20

I made a wedge of some scrap ebony. See the original discussion for the details. Here's what I did with the wedge.

And the result.

[darren]

Rick is about a billion times more knowledgeable than I so he'll steer you right; Fall-away good, gap bad.

Provided the string height at the bridge is within reason, shims are fine, I wasn't trying to say otherwise...

again, pictures will help.

[darren]

Oh I wasn't taking anything personally :) I'm working hard at my own pile of mistakes!

[JLT]

Thanks for your input, folks!

In answer to your questions, this wasn't a kit, so there are no instructions. And there is no soundboard "dome." Gauged from laying a ruler on the fretboard and seeing where it ends up over the bridge, the neck angle looks perfect just as it is, and I don't want to muck with it.

I think I'm going to go with penndan's suggestion to make a shim to fill the gap. I'm used to doing that with the A-style mandolins I make.

[Dan Bombliss]

Take this one as you will, but you can get away with a little bit, not sure if it will fully fix you're problem, but if not, it will surely make you're shim a little less noticeable.

viewtopic.php?f=5&t=5224