Another Weissenborn Copy

[Frenchy]

Hi All

I'm opening this topic to talk about the project I'm working on at the moment : a Weissenborn copy made of blackwood. Nothing original, I'm just tring to stich to the StewMac plans but as it's only the second guitar I'm building, there is still a couple of things I would like to clarify about braces.

Here's a few pictures :

Well, this is the rosette, made of curly mapple. You can see I wasn't lying when I said I've been reading this forum for quite a bit :)

So yeah, here are my braces. I've stopped here after a rought work on it as it looks a little bit overbrace to me but I'd like an advice before removing too much material. The section of all my braces is 0.95 x 1.45 cm. All are dead flat, including the X braces for which I kept a square section. The top is 2.5mm.

Two questions about that :
- first you probably noticed my bracing system is not symetric : that's because a fingerbrace glued at the wrong place had to be removed. But as I read here and there that bracings could be lighter on the bass side so that the sound will be more bassy. I've also seen some weissy with only 2 finger braces instead of 3. So I'm hesitating. Should I glue a new one, remove the 3rd one to keep it symetric or can I just let it as it's set ?

-The X brace should be scalloped or not ? Again, I've seen several craftmen keeping it straight, flat, with a perfect square section, but it seems to me it's gonna be too heavy. I've also seen in Trevor Gore's book that X braces had to be tapered down to 8 mm...
Tapering and scalloping the X brace includes I will have to carve the inner end of the finger braces.

Considering I've seen a few guys doing well on blackwood weissenborn on this forum, I would deeply appreciate to know how they set their braces.

As I could work on the top bracings, I've bent the sides : 1st time I'm working with blackwood, I was surprised how bending is easy with that tonewood.

[ozziebluesman]

Hi Frency. Your weiss looks great. Very nice blackwood.

I've built five weiss style guitars now and I am very happy with this brace design used in the last three. This is a copy of the MIMF plan but with a few modifications in the bridge plate area where the bridge rolls forward and causes the area between the sound hole and bridge to sink. I did a lot of research on coming up with a design that will stop this. I found that Herman Weissenborn come up with in 1925 what's now known as a Christmas bridge plate to stop that issue and be able to fit heavier strings to make the instrument louder. The metal dobro guitar design came out and killed the poor old weiss in volume and the guitar faded into the distance. Herman's bridge plate design is about 4 mm thick in the area where the string are located and then thinned out to the edges to about 2.5 mm. I made a xmas bridge plate about 3 mm and then glued a 1 mm laminate on top to get 4 mm thickness. My tops are about 2.5 mm and I have built three weiss copies now with that design and the tops have not moved. I use 9 mm x 9 mm for all braces except the transverse at 13mm x 15mm leaving out the third finger brace nearest the sound hole. My mission when designing a top with better structural integrity was to try and maintain the same brace layout as Herman did to try and capture his instrument sound just address the sunken chest issue as well.


There are a few more brace designs here on the forum that work very successfully so check them out.

Cheers

Alan

[Bob Connor]

My bracing is quite different and a lot lighter than the original ( although I do beef it up more around the sound hole and under the end of the fingerboard with the "A" braces.

I am thinking of trying the traditional bracing next time a round but it looks awfully over-braced to me.

Regards

[Frenchy]

Thank you both for sharing your knowledges. The "christmas tree" under the bridge totaly makes sense and I was planning to add something too.
But I don't understand this A brace or any similar heavier reinforcement above the soundhole : the original brace and a thick finger board should be enough to keep the top straight, no ?

[liam_fnq]

I'm keen to have a go at one of these in the near future. Bob, what are the dimensions on those braces?

[Bob Connor]

Frenchy - that area of the instrument is under quite an amount of pressure (as are any acoustic instruments).

The rotational forces of the bridge will be attempting to belly the lower bout as well as sink that area around and above the sound hole. So I always try and reinforce that area (and I use a patch around the sound hole for the same reason) That upper bout area is not is not that crucial for producing sound so I always try and strengthen it. In fact I've used carbon fibre to the arms of the A-brace in the last one I built.

I believe that it gives me more latitude in bracing the lower bout very lightly as I reckon that's where most of the sound comes from in an acoustic instrument.

However that's just my idea of how a guitar should work and there's more than one way to skin a cat. You just need to find what works for you by building a few.

I'm going to build my next weissy using the Stewmac plans just to see how it sounds so I can compared to what I normally do.

Liam - the x-braces are 8mm x 13mm and are very V shaped but not scalloped. ie I carve quite a bit off the lower legs. The lattice is 5mm high by 3mm wide so they are quite fine but very stiff and spread the load over the whole area. I did used to cap the lap joints but I thought I thought it made everything too stiff.

Recently I've stopped doing the lattice next to the sound hole and gone back to 2 finger braces as I think one of the roles of those braces is to stop the bridge and bridge plate rotating and I feel that the finger braces do that better than the lattice.

The other change that I've made to the Stewmac design is how the side braces into the neck area join into the headstock.

It's a bit hard to explain so I'll post a pic of how I do it. The neck strengtheners are notched into the headstock rather than butting up against it.

[Frenchy]

Hey Bob, nice explanations here. Cheers

I've seen your headstock design a few weeks ago an it's already built that way on mine : I must admit that's a simple and briliant idea, which makes perfect sens to me.

Thanks for your advises, even the non-intentional ones !

Seb

[Crafty Fox]

Hey Frenchy, I can see a shiney new Veritas block plane. Carbatec?

[Frenchy]

You're right, mate . I also bought a ridiculously small veritas, pretty handy for shaving braces.