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Since you need to bring the saddle down to about 10mm, you need to lower the string height at the 12th fret by about 2mm. How thick is your fingerboard? If you can shave a couple of mm off the bottom of it (tapered from the 1st fret most likely), then that would be the way I'd go.

You need to re-evaluate why your top came out flat when it should have been domed. The extra 4mm saddle height is most likely due to the lack of dome on the soundboard.

One reason for the dome flattening out may be that your braces are over-strong perhaps? It's always befuddled me why, using the solera building method, one goes to the trouble of doming the solera and then glue flat braces onto the back of the soundboard. When unclamped, the braces will try to straighen out again naturally, de-doming the soundboard (making it flatter). If the braces are stronger than the soundboard, they will win and the soundboard will become flat again, just like the braces. The simple answer is to pre-shape the braces to the same shape as the wanted dome, but as far as I can tell, no one does this.

Cheers,
Dave F.

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Cambrian Guitars

"There goes Mister Tic-Tac out the back with some bric-brac from the knick-knack rack"

I disagree, Dave. I have no issues with my tops losing their dome coming out of the solera.


Bridge blank sanded to 25' radius on a belt sander.


I believe it is a humidity issue, Filippo. What was the RH when you glued your braces? You know, Hauser forced the dome in his tops with the bridge, don't you? Tapering the fingerboard is probably going to be your best bet, unless you want to take the bridge off and get the dome right first. Nothing wrong with a 2 mm taper on the treble side and a 3 mm taper on the bass side. I start at 7 mm at the nut and taper to 5 at 19 on the treble side and 4 at 19 on the bass side, approximately. i actually adapt it slightly depending on the action, but it only varies by less than .5 mm. There is nothing wrong with 11 or 12 mm at the bridge. It will actually give you more volume, most likely, than 10mm or less. I shoot for anything in the 10 to 12 range.

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Waddy

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Sound Clips of most of my guitars

It's simply not necessary to shape the braces to fit the solera. I can't recall a pressed style fan brace ever flattening out with one of my builds and it obviously has not for countless numbers of Classical makers. It's pretty much standard practice. I have had true flat tops sink a little but those are a different case. Clearly something went wrong with Filippo's soundboard.
I'm not familiar with how Hauser domed his Top. I guess there are two ways to achieve the doming using the bridge ie. gluing the bridge to the unassembled soundboard or after the instrument has been assembled.

There you go! 30% is really dry compared to the 45 - 50 you are talking about now. You have a very low baseline humidity set for that guitar.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Hello Fillipo,
Did you verify the neck angle on your build? Having such a high saddle might undermine your bridge and top in time. I would try plane the finger board to allow a proper set-up. If the top ever decides to resumes its shape, you could try playing flamenco on it......
John

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John Nowicki

Hi Fillipo,
I remembered reading about your neck issue in the past; that is why I brought it up. I have taken my top out of the solera, after bracing and neck gluing, before gluing the sides, but not for very long. I will make it a point not to do that again following your experience. I never lost the dome in the top though. My seven fan braces are usually no bigger than a popsicle stick in cross section ala Robert Ruck; but I guess I have been lucky. It does make sense to me that if your fan braces are too heavy, they might force the top flat if not clamped properly right after gluing. Alot of dynamics and static forces at work here. Best of luck getting every thing right.
John

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John Nowicki

Eugene Clark claims he makes his soleras 50% deeper than his desired doming to compensate for springback.
Ref. American Lutherie, Number 92, page 11

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Jim Watts
http://jameswattsguitars.com

If I remember correctly, Hauser style are built with top flat.
The only dome introduced was with the bridge and an arched lower harmonic brace.
So I guess your guitar would work out fine.

As for the neck angle, I think planing the fret board at the 12th fret.
Maybe you should glue up the bridge with the dome before doing the frets
Then you can deciding whether if the doming in the bridge is enough to compensate for it?

Well a higher saddle is better than the other way round, where the saddle is too low.
I had a guitar which the forward angle is so much that even lowering the saddle to the bridge height, the action is still too high.
I am considering planing the fretboard at the nut end to correct this, as advised by Mike Collins.

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Sen CL Goh
http://senguitar.blogspot.com