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Garnet shellac problems
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Author:  Michael McBroom [ Thu Jan 11, 2007 6:25 am ]
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I'm french polishing the top of my latest guitar right now, and had to fill a small ding that showed up after I laid down a couple of applications of shellac. After levelling the area, I've been plagued with an unevenness in the color there ever since. I've tried using just alcohol on a pad to spread the darker color around, or lift it, I've tried sanding the area lightly, and neither of these procedures has given satisfactory results. At best, I've managed to move the dark and light areas around some. It just seems to be getting worse, and it's getting really frustrating.



So this question goes out to those of you who are skilled french polishers: what would you do to even things out?

Best,

Michael
Author:  jfrench [ Thu Jan 11, 2007 7:24 am ]
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Michael, I realize this might not be much help right now, but if you size with egg white it helps to keep the color even.
Author:  TRein [ Thu Jan 11, 2007 9:02 am ]
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Sorry to say I think you are sunk and will have to strip the whole top if you want it even. I find color coats have to be isolated between clear coats. Seal with blonde shellac, FP with color coat, top off with blonde. It is questionable whether one will be able to invisably retouch a color coated top in the future. An amber colored shellac sure looks nice on a new top though. One of those little trade-offs.
Author:  Michael McBroom [ Thu Jan 11, 2007 9:17 am ]
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Argghhh. . . I was afraid of that. Guess I better go mix up some superblonde.

Best,

Michael
Author:  Mike Collins [ Thu Jan 11, 2007 10:38 am ]
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Michael
I spray a thin coat of blond on my guitars to seal and help with color balance later on.
I use a small automotive touch -up gun -this helps to evenly distribute the shellac.
Then I go ahead with my F.Polish if all is fine with the sealer coat.
The sealer coat not being very rich in color is easy to fix if you have a bad area.

I hope this helps
Mike

www.collinsguitars.com
Author:  Michael McBroom [ Thu Jan 11, 2007 11:55 am ]
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Thanks, Mike. This is the second guitar I've used garnet shellac on, but now that I think about it, I had used superblonde as a seal coat on the first one. Guess that's why I didn't run into any problems with it.

Joshua, your egg white size has me curious. Can I get your recipe? For example, do you dilute it with water or?

Best,

Michael
Author:  LuthierSupplier [ Thu Jan 11, 2007 11:59 am ]
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Michael,
I have the same problem on my bouzouki. Found out that I had sanded down to bare wood. Once that happens, you have to start all over. Nothing you can do about that.
Good luck, and I feel your pain!
Tracy
Author:  jfrench [ Thu Jan 11, 2007 1:25 pm ]
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Michael,

Just crack an egg and drain the whites into a margarita glass (or something easy to dip a brush into), mix it up a bit and brush it on. Let it set overnight and sand it lightly with some 400 grit.

Thats your seal coat, instead of shellac. It works very well.
Author:  crowduck [ Fri Jan 12, 2007 10:03 am ]
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Michael,

The egg whites/albumin sizing/ground was used 'way back when' by the Cremona luthiers like Stradivarious and such. There are lots of 'recipes' that can be found for it. But here's the basic way the violin makers make it up, and I've tried it this way. Get 1 or 2 eggs at room temp, separate the whites into a mixing bowl, then using an electric cake mixer/beater, whip the whites until stiff. It will look like a solid white foam. Cover the bowl, and let stand at room temp overnight 16 to 24 hours. A light thin liquer will have drained from the foam to the bowl bottom, pour this off into a container and use this to size/ground the wood. No brush necessary, just dip fingertips, and rub into the wood in a circular pattern, ending going cross grain. Move quickly as this stuff dries and hardens fast. As mentioned, let sit overnite, then sand lightly. Some recipes are very elaborate adding things like sugar, gum arabic, and other things to the whites b4 whipping. Try experimenting on some scrap wood, eggs are cheap, and can even be bought already separated at the grocery store.

CrowDuck
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