Official Luthiers Forum!

Hello everyone,

I'm carving the neck on build # 1 (Ditson) before final sanding & french polish and have a couple of things I'm looking for advice on how to fix:

1) My pyramid bridge has a small amount of tear out on the underside at one corner that will show a slight gap once glued down. Is there a good way to square off that corner w/out just reducing the thickness (no bondo please )? I've already contoured the bottom of the bridge to match the radius on the top.
By the way, my bridge weights 22g, is that on the light side for a pyramid?





2) I have a small gap where the fretboard first meets the top. I'm sure this must have been discussed before but I was unable to find the post... Something tells me superglue would be a terrible idea since it will find it's way back to the truss rod. Maybe epoxy or something else?


Thanks for the tips.
Mark

You can repair the small tear-outs on your bridge with ebony dust and thin CA. Use a pipette filled with CA, put a couple of drops where the repair is, drop some fine ebony dust over the CA, watch it smoke and cure instantly. Then clean up with a block and sandpaper through the grits. You may have to repeat that a couple of times before it is clean and invisible. The tear outs seems small enough not to affect anything. 22g is perfectly fine.

The issue with your neck could be a couple of things. No epoxy, or anything irreversible there.
Your neck angle may be not set back enough, or the top under the FB extension is not perfectly flat, or the FB extension bends down. Or a combination of those 2 or 3 problems.
I would first check the flatness of the top under the FB, you need to have it 100% flat.
Then I would look at the neck angle, and check with a straightedge how tall the bridge/saddle will be (you want around 1/2" above the top). Ideally you want to have the same angle on your neck cheeks as you have between your top and the upper bout centre, and have 1/2" clearance between the top and the saddle location when you put a straightedge on your FB.
Sight your fretboard from the nut and make sure the FB extension does not dip down.

_________________
Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Thanks Laurent,

I will use the CA/dust method for the bridge and post up pics of the result.

Regarding neck angle, the problem is that my top makes a slight dip about a 1/4" before it reaches the sides at the heelblock. I tried to sand the top as flat as possible before attaching the neck/FB but didn't want to make it too thin. So, I'll have to fill it in some way but I don't think it will be a problem since my FB angle is good (please let me know if you disagree).

Unfretted, the straight edge goes just above my 3/8" bridge and the FB has a little fall away towards the soundhole that begins just after the 12th fret as recommended by some on this forum. There is no dip where the gap is below the FB (yet).




Thanks,
Mark

3/8" is good, actually in my previous post I should have written the height of the string above the top should be 1/2", not the space between the ruler and the top. Sorry for any confusion. The bridge looks high though, but it may be the picture.
How thick is your top and do you have any reinforcement above the soundhole (neck block tongue, popsicle brace)?
You need to have this part under the FB flat. Any filler will look bad. Pencil the area and scrape or sand (with a flat block) so that you're taking material only between the soundhole and the neck pocket, but nothing close to the neck pocket and soundhole. It looks like a few thous in the middle will do the trick.
Only solution if you can't flatten this area (most likely you can) is to glue a wedge shaped sliver of ebony under the FB extension and shape it to accommodate your curve there. At least it will look invisible under finish if well executed, but the FB extension might look funny.

_________________
Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

Ok, I like the wedge idea. My neck (dovetail) & FB are already glued so I don't think I'll bother removing them since this is build #1, but I'll mark this down as item number 32,738 that I will do better on build #2.

The pics do distort the size of the bridge which measures 0.365" in the middle of the front.

I'm pretty sure this gap issue was caused by my over-zealous scraping flush of the bindings in that area, having not fully understood potential neck angle issues at that time.

Ciao,
Mark

Laurent gave you fine advise here. From what I see in the pictures, if the fretboard is not fretted yet I would level it after you address those issues since it looks like its not totally flat.

Well done for a first.

_________________
Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

Thanks again for all of the tips.

I need to do a little more touchup but the CA/dust method worked great on the bridge:


Here's the FB gap after gluing a very tiny wedge (0.017" thick) on both sides. Once the neck carving is done & I clean up that area I think it'll be alright:



Have a good one,

Mark