soundboard thickness

Ken Bloom

Can anyone tell me the average dimension for the thickness of the soundboard? The Charle blueprint doesn't seem to specify a dimension and as drawn it seems to be under .100". Any information greatly appreciated!

Josh Hegg

My final sound board thickness is right around 1.75mm.

Cheers,
Josh

Ken Bloom

Thanks Josh. Boy, that's thin! Did you graduate your top at all or go with a single thickness?

Josh Hegg

I try to get it the same all the way around. However at the very edge it might go up to 2mm. It is thin enough to shine a light and see the bracing. My Dupont is the same way.

Cheers,
Josh

Ken Bloom

Thank you so much. I think I'm begining to understand these guitars. They seem to be more like heavy lutes. Time to sharpen my plane!

frater

Maccaferri's project was heavily influenced by his mentor Mozzani' s mandolins...

Ken Bloom

Do the less expensive guitars have tops this thin or, maybe, is this one of the differences between the inexpensive factory guitars and the fine handbuilt ones?

Josh Hegg

Most of the less expensive guitars have a thicker top. Also a thicker finish. The key to these guitars is light, light, light construction. I have talked to other luthiers that hate working on GJ guitars because they are afraid they are going to break them because they are so lightly built.

As for the mando similarities that is correct. The only making now that has a great Selmer replica is Dupont. His VR is an amazing guitar and has a top that is perfect. Not only is it supper thin, the arch is nice and high and he built in the break! Not many builders build the break. They just go for the thin and arch. On the guitar I'm building now I have built the break and it is a lot more work. So I understand why other builders don't do it as much. Now that I think about it I think that Leo Eimers builds the break too.

Good luck on your project
Josh

Ken Bloom

Thanks Josh. Since this is my first Selmer style instrument, I think I'll stick with thin and arch and see how it goes. I've done bouzoukis in this way, copying a busted one I had from the '20s. Same approach of very lightweight, high arch and thin top. I am assuming the sides and back are equally thin. Now the bracing system makes sense to me as well as the light stringing. This is the best and most specific info I've been able to find. I can't thank you enough!

Colin Perry

I was just over at Martin Tremblay's shop the other day, and he was talking about the similarities between selmers and mandolins. He also builds in the break.

Bob Holo

There is an underlying assumption here that is probably understood - but just to make sure it's clear, the thickness of the soundboard is proportional to its quality and stiffness... IE, a nice fine grained stiff top with good medulary rays that has been kilned right and allowed to adjust to the environment in which it will be worked so that it is stable... can go much thinner than a poorly kilned spongy low grade top. In fact, you'll get a better top out of a cheap piece of wood if it is thicker because even if it does manage to keep from cracking under pressure - a spongy piece of wood needs some thickness and stiffer bracing to generate any oomph. No two tops are the same and so each should be brought to the right thickness for its capabilities and characteristicss. So, when Josh thicknessed his top to those dimensions, I'm guessing he did it because the piece of wood called for that thickness. In general - taptone seems to be a misnomer. The idea is to tap and thin and tap until there is no real distinct tone... rather a nice low resonant response that decays slowly (slowly for a piece of wood... which is a several seconds max) Most factory guitars go to about 0.1" (2.5mm) because they can use a reasonably good grade of wood handled in reasonably uniform fashion and have it produce reasonably good tops that stand a reasonably good chance of not cracking if they're treated reasonably well. Does that sound reasonable?