Soundboard shows bracing after French polishing

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TrevorMag
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Soundboard shows bracing after French polishing

Post by TrevorMag » Sun Dec 26, 2021 7:50 pm

Everything looks really nice in the white, then when there's a bit of gloss on it, the contours of the bracing are revealed.
Admittedly I am making it hard for myself by using an A-frame bracing design (a la Tacoma), which is probably harder to conceal.
My first insight: sand a bit of a crown into the bridge plate next time - that might make a small improvement.
How do you folks avoid this?

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kiwigeo
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Re: Soundboard shows bracing after French polishing

Post by kiwigeo » Sun Dec 26, 2021 8:11 pm

What's your sanding method. Are you using a hard or soft block behind the paper?
Martin

TrevorMag
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Re: Soundboard shows bracing after French polishing

Post by TrevorMag » Mon Dec 27, 2021 5:36 am

kiwigeo wrote:
Sun Dec 26, 2021 8:11 pm
What's your sanding method. Are you using a hard or soft block behind the paper?
Cork block

simso
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Re: Soundboard shows bracing after French polishing

Post by simso » Mon Dec 27, 2021 11:49 am

Is this happening without any string tension being applied, that is a fresh clean build not strung up yet

Steve
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Dave M
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Re: Soundboard shows bracing after French polishing

Post by Dave M » Tue Dec 28, 2021 2:37 am

I think actually that this is a feature rather than a bug as we used say in my computer days.

If you have built a responsive guitar which basically means a fairly thin top then the braces do tend to 'telegraph' through.

As people above have suggested sanding technique can make some difference but likely o happen over time anyway.

Does it sound good? That's the main thing.
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Allen
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Re: Soundboard shows bracing after French polishing

Post by Allen » Tue Dec 28, 2021 7:36 am

Thin soundboard will just about always show the braces telegraphing through. Think of it as a feature of a lightly built responsive instrument.

Saying that, this did bother me on my instruments and when I started doing some research found that a couple things could help aleviate the "problem".

First up I switched to vacuum clamping my braces. Using Go-Bars was appling too much pressure to the soundboard and compressing fibres that was really compounded by the very thin tops on a ukulele.

The second step that really made all the difference was going to a slightly thicker top but using lighter bracing. Actually gave me much better tonal results, volume and sustain and I never have the braces showing through now unless the humidity has gone through the roof and the soundboard has swelled up far more than it really should have been allowed to.
Allen R. McFarlen
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TrevorMag
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Re: Soundboard shows bracing after French polishing

Post by TrevorMag » Wed Dec 29, 2021 3:39 pm

Thanks folks, think I'll chill about it for now

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