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Hi. I made a Weiss style that I never finished on the finish,
and strung it up about a year ago.
Top ended op around .110, x brace 5/16" x 9/16",
saddle is a bit higher than 5/8" and no braces are tucked in.
I noticed at the end of the f.b, the top ( which started with a 25' radius)
has sunk in.
The guitar sounds good, but how long will it last?
Should I just see what happens to it?
Here are some pics.

Hi Allan;
If you get a chance to see any old (real) Weissenbornes you'll see this is pretty common.
To help combat this issue, I put a fairly hefty "A" brace in the upper section, straddling the soundhole. This brace is notched into the two transverse braces above the soundhole & extends well into the "neck" area. My oldest Weiss has been strung up for about 6 years & still looks fine.
A few years ago, i got the chance to play with a Michael Dunn Weiss that was about 5 years old at the time. It was collapsing badly around the soundhole & had a scary amount of upward deflection below the bridge.
The owner told me it had started to deform quite soon after it was built, but it had stabilized after a year or so. He wasn't worried in the least. Yours will likely be fine. It is nowhere near as bad as the Dunn I mentioned.

Thanks Daniel.
The bracing is evolving for me on these things.
Tuck at least the upper x,
tuck the upper braces, and make them heftier,
and put a heavier brace on the back at the upper bout,
as the bending of the back seems to dish that area.
I slacked the strings and it is almost dead flat now,
and I will try putting a big brace at the end of the fretboard.
I don't think that will affect the tone much.

Allan;
The first time I saw the Weiss plans, I knew I wasn't going to follow them exactly. From your picture, I see you came to the same conclusions. Higher, narrower top braces are a definite plus IMO. I kinda "modernized" the lower top brace pattern too.
Before I built my first Weiss, i looked at three older ones & all had the deformation you noted.
I'm not sure that heavier transverse braces will help much. There's still all that unsupported space between the upper transverse braces & between the lower transverse brace & the upper legs of the X.
The "A" brace I described seems to be a good solution. The braces are only 1/4" wide & 1/2" high, so they don't add much mass. Notching the A brace into both transverse braces takes a bit of time, but I'm convinced its a good fix for an obvious & recurring problem.
Adding mass in the top area above the soundhole is probably not going to affect volume & tone much, if at all.
I hope we get some input from others on this issue. Always fun to see how other folks find different ways to skin the cat.

I thought maybe an x brace at the upper bout next time,
heavier upper ends on the x,
and definitely let the x, finger and traverse braces into the sides, at the problem area.
My original stew mac plan called for 3/8" x 3/8" braces everywhere.
I knew on my first these were way too flimsy.
This koa top, which I didn't use, will be used on my next.
It needs some shaving, as it is heavily braced now.
Plus, the soundholes arn't in the middle of the guitar!

That X brace should do the trick! Cool soundhole arrangement. Looking forward to seeing that one finished.
Cheers! Dan

This is what I do:

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

And this is what I do.



Regards

_________________

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Bob Connor
Geelong, Australia

Thanks all!
We'll see what happens on the next one.
I'll swipe those pics and use them for a reference.