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Silly story follows, not for the faint hearted. Some might shout "heresy!"

Sometimes i amaze even myself...

I could not resist waiting until tomorrow to unclamp the bridge. (yap, i should have waited 24 hours...)

After I found out that my small desktop speakers were dead, a bulb lighted.  I used sticky tape to fasten the top on the guitar body and I strung up the E's (one at a time, I don't feel that lucky with that fresh bridge)

It sounds...hmmm. I can compare against my 600$ cedar Alhambra, which has a dark warm timbre.  The duct tape concoction sounds noticeable lower in volume, not much resonance, dry treble and not much sustain, but the tone is promising, with clear and sharp trebles (or at least i hope so)

I wonder how will she sound in a couple of days when I'll have enough clamps to proper glue her up.

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Alex,

The GAL Red Books have some good articles on plate tuning and guitar acoustics. Alan has done a couple of excellent articles on the subject.

I dont know about your bridge clamping jig..it looks like it would be at home in a Frakenstein movie. Be careful clamping that bridge!!

Testing done.. i hope I got it at least 10% right.  The tea dust moves from 196 to 246.9 Hz. Outside that, it's not doing much. Before each note change, I piled the dust back around the bridge.
At 196 hz it goes ballistic. At the others the tea jumping around is not so dramatic and it takes a few more seconds till I get the pattern.

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Tea dust....you mean tea leaves? An interesting alternative to glitter. Im starting to get interested. Think I might do a bit of experimenting myself.

yes, tea leaves from 3 or 4 bags. I made the stands from several layers of mousepad black foam, and used a 10W monitor and 40W amp 50% volume. The speaker has to be as close to the bridge as possible. At first I made another stand for it but since it was just a bit larger than the plate it felt on it while moving from the vibes, luckily nothing happened but such an event might easily crack a plate. So it's best to hold it with your hands.

It's a fun process and also smells nice :) but the whine drives one nuts.

These patterns are quite interesting. I hope Alan can make smth out of them :)

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There's a tendancy for the very lightest dust to actually get suspended in mid-air at the spots where the plate is most active, instead of bouncing off to the parts where it's not moving. When you turn the amp off to take the picture there's dust everywhere, and it's hard to tell what was moving and what wasn't. another thing that would help would be to see the mode of the whole plate, not just the part below the waist. That clear line at 196 could be part of a couple of different modes, but I can't tell. Try looking at the whole plate, and lightly blowing the dust off the moving parts before you take the pictures.

It might help to add that there are 2 types of tea in there. The red one is coarse, while the yellow is much finer. It did not spread the same as the red one.

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You're going to be in big trouble when your wife cant find the tea bags in the kitchen. How are you going to explain all this to her?

Not married   Can have sawdust all day long in my hair. And the mess all this created is colossal.

Seriously now,  I just finished another shaving session. Thinned and flattened all fan braces, also reduced the height of the central bar from 19mm to 14.  Also thinned the plate a bit, it now ranges from 2.7 to 2.3mm on the treble half.

But so far no sonic improvement, still sounds tight and low volume. I still blame it on the sticky tape joining though, and hope it will start singing once it is properly glued to the sides.

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If you really want to see what it sounds like attached to the sides, why don't you just go to the neck, top, side assembly stage and redo the testing. You still have access to the braces at that stage. The taped joint has to add a lot of damping, I would think.

Jim

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Jim Kirby
kirby@udel.edu

The back is properly glued. This is not a guitar i make from scratch (that will be my next project), but a factory one. I am only replacing the top plate. 

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Someone just told me that after he cuts the binding ledge, the top plate has a dead sounding tap tone, and it sounds ok again after the binding is glued in.   So more hope for me :)

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Oook, got the plate glued up.  This didn't go as easy as i thought, of course I had to screw smth up. I had it all well figured it out, but when i was forcing in the 10th gobar out of 20, the workbench (which is actually my computer desk) lifted, resulting in a few dents int he plate. With all the excitement, I simply forgot to put the weights on the dang table. 
I put the weights, picked up the bars and in the end it glued up fine i think. With a blade from a cutter I trimmed the plate close to the kerfing level (this is a factory guitar with a new top, so the ledge is mostly there) and today i am going to try and make the ledge perfectly clean and square. 
I did some trial binding bending with an old hair-curly-do iron and it works great albeit very slow- it only has 26W. It still boils the water I sprinkle on the wood. The problem is the small pipe diameter, i have to be careful not to do sharp bends.

And sound wise, with the plate glued up the volume picked up a lot and I think it is already as loud or even louder then my 700$ Alhambra.
The tone is brighter and clear, but still sort of dry and thin. I hope she will start to sing once I glue up the binding and thin the plate.  Not sure if I should start thinning now or after I put the binding. Without binding it is a bit easier to see how much material is sanded.

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And I thought I was primitive splitting a 1" x 6" x 8' board lengthwise with a crosscut saw... Glad to see i am not the only one running in the "cheapest guitar made" category.

What i need to know now is where do you get one of those high-tech penknives you talk about? Are they expensive? I have been using broken bottles that i gather along the roadside because i have worn my fingernails down to nubbins.

Bad news I'm afraid, they cost a lot, I think 90 cents ! 

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She currently looks like this.  Over the last 4 days or so i shaved a few microns off the top, then waited and listened...seems to improve every time but maybe i just imagine. I think that right now the bulk of the thickness is between the hole and the bridge (maybe 2.6mm?), and the upper bout is mostly close to the initial 2.9mm. 

Here is an audio sample. Sorry for the bad playing...just learning this wonderful piece by Dilermando Reis. There is also buzzing, but I'm out of saddle blanks.

I like how she sounds.  The high E is quite strong, certainly beyond my expectations. But I could use some more overall warmth...

http://ursultrubadur.ase.ro/modules/xg2/engine/main.php?g2_v iew=core.DownloadItem&g2_itemId=77109

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It's strange how she changes voice everyday. I noticed it takes a few hours after every sanding session, changes in voice do not occur at once.  The pic is took after cleaning up the yesterdays 100 grit scratches on the upper bout using 180 paper. I problably removed 0.1mm off the upper bout. Also smoothed a bit before the bridge.  Then went to bed for an afternoon nap, then played for a about 1h and noticed the sound became darker, with a bit of volume expense.  The difference is clear:

http://ursultrubadur.ase.ro/modules/xg2/engine/main.php?g2_v iew=core.DownloadItem&g2_itemId=77124

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