Dupont Chorus f-hole top bracing

deadedith

That's a deal, AE!

Bones

Hi Dave,

I just used book binding cloth which is just a heavy woven fabric mesh (not solid fabric, but with air holes between the heavy threads) and then laid that down over the f holes and rubbed some woodworkers glue onto it just enough to saturate the fibers and glue it to the wood. Then after it dries just cut the cloth around the inside edge of the f-hole. Provides some fiber reinforcement of the delicate corners of the holes. Not sure if it is necessary on an archtop since the top is a bit thicker but might not be a bad idea for a selmac.

I believe that this fabric material is what book makers use to reinforce the 'spine' of the book.

deadedith

Ah so. Thx.

Archtop Eddy

Okay, the cat's out of the bag on who built my new f-hole guitar. Our fellow Djangobooks member Ahab guessed the make and model as Leo Eimers' copy of my 1953 plastic Maccaferri guitar. The Eimers model is called EG-AE40G. (picture attached).

One of the things I asked Leo to do was to make the guitar not only look like the plastic guitar, but to make it "feel" like it too: neck dimensions, string height and tension, bridge height, and even the height of the strings above the top near the bridge. He knocked all of these details out of the park!

Here is what Leo had to say when building the guitar's top.

In a setup with a wooden (spruce) top, tailpiece and floating bridge the bracing pattern must be adapted. Many considerations!
-- I want to have a thin top for the best sound.
-- I want to have a bracing pattern that allows me to voice the top.
-- I also need enough strength to carry the pressure of the bridge.
The area of the top, between the bridge and the fret board end, where also the F holes are located, needs to rigid and stable to avoid a collapse of the top at that specific area.
In general I want to add stiffness where needed without adding too much weight!
Voicing the top is mainly a matter of shifting mass. So I need the possibility to shift mass.

With a wooden top I work with arches on both axis (length and width). The width arch is created by arching the braces. The bridge is standing on this arch. And as you know an arched surface can carry more weight than a flat area. The arch in length of the body is created by working the sides. At the bridge location the sides are higher then at the neck location. The sides are not rectangular. The neck angle ( = bridge height !!!!) is defined by this angle.

To avoid the collapse of the top at the f hole location I have to add bracing parallel to the f holes. Fortunately I have experience with my full scale models Amati and SAE13 (a Di Mauro copy). I used the basics of this pattern bracing pattern also for your F hole Maccaferri.

So there you go. He did all of this and as you can see, he did it VERY well! AE