Official Luthiers Forum!

Building a hybrid nylon string -
Anyone gluing flat/un-radiused fan bracing to a soundboard in a solera/radius dish?
Does it hold the radius after drying?

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

"Does it hold the radius after drying?"

Yes, it holds the shape - although when I use a solera the arching is not a true radius.

I switched to flat braces after my first classical, At a GAL 6 or 9 years ago I heard a talk by Eugene Clark where he suggested keeping the fans unradiused. He said they would spring back about 50% so he makes the dish about 2x deeper. I found this is true but I have found that my 2 mm deep dish still gives me a 2 mm or so dome with string tension. So I switched to flat braces without deepening my dish. My top are relatively thin at 2 - 2.2 mm. A thicker top may have more spring back.

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http://www.Harvestmoonguitars.com

Really? If you just clamp flat braces to the top in a radius dish the top will conform and stay that way? I would have thought it would have sprung back flat.

I've always glued them on flat then glued in the radiused transverse bar.

I wonder what the stress imparted into the top by clamping flat braces to a dish would do to the tone of the guitar?

Like Clay, my solera is more of a parabola than a dish. I use different configurations and thicknesses of tops and bracing depending of whether it's a classic or flamenco but have always glued flat braces. The tops take the shape of the solera regardless of type of wood, thickness, taper or brace configuration.

Even ignoring the braces a radiused top imparts stress, the flat braces pressed into a dish is just an incremental amount of tension. A guitar is all about stress or tension. A bit more pre loading of the top may improve the performance of the top.

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http://www.Harvestmoonguitars.com

That's what I thought folks, perfect.
Reason I'm asking is this will be a hybrid, nylon strings but bolt-on neck and will be constructed using radius dishes much the same as a steel string.
The soundboard will have a bridge patch, and if I use flat fan bracing it makes taking a check out of the fan braces for it simple.
Have to keep the humidity firmly under control too, winter makes it easier to keep it down.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

One highly regarded guitarmaker for nylon string guitars and lutes here in Germany told me, he is gluing the already curved braces on the top, without using a dish, just on a flat surface. When taken of the clamps, of course the top bends according to the curve on the braces. Also nice....

The two classical makers I studied under in the south of Spain both glued flat braces to their tops. Stephen Hill even used a 6 meter radius dish to glue the fan braces instead of straight into the solera and used a hair dryer to warp the top prior to brace glueing (apparently it's the Granada secret)

A well-known builder I know glues his braces flat after the top has acclimated to 8% RH. When the braced top is returned to the main shop with his normal 40-45% RH, the top expands and he gets his dome.

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formerly known around here as burbank
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http://www.patfosterguitars.com

What thickness of flat braces?

From what I've seen, talking Classicals, seems to be 6mm or less in height (Courtnall, Making Master Guitars )

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

When you say flat braces you mean fan braces right? I can't imagine imparting an arch into the fan braces becasue they are so small. I've only built about a dozen classical guitars but I always glued the fan braces on flat and arched the lower transverse brace to give the top it's shape, and strength.

The very first article I saw on building classicals, the builder shaped the fan brace on the glue side to the desired arch. Each brace was glued with a straight, stiff backer on the brace and a thin flexible backer was used on the top of the guitar, so the top was drawn down to the curve. Regular clamps. No work board was used.

I glue my 4-5mm tall braces in the go-bar not pre arched.
the top arch holds when removed from the dish.
A The #1 & 2 braces are not glued till the top gets to the solera.

Mike

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Mike Collins

Are the #1 & 2 braces transverse braces?
Possibly UTB and a transverse?

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Yes.
#1 is slightly arched .
# 2 is arched to fit the solera .
IT'S NOT THE SAME ARCH AS THE FANS

I use a radial bracing now-all braces below #2 are arched in the go-bar.
same as trad. bracing



Mc

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Mike Collins

THANK YOU.

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.