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Help with a couple mistakes
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Author:  Kelby [ Mon Aug 29, 2005 9:31 am ]
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I made a lot of progress this weekend with a box, but ran into three snags. Any help is appreciated.

First, the rosette has thin maple and coco purflings around the inner and outer curves. In one area, the maple apparently wasn't seated all the way down, and as I sanded the whole thing flat, the maple disappeared for a short bit. The lines are thin enough that it doesn't jump out at you, but I am thinking about about taking a litty-bitty paintbrush and "fixing" the area with a line of paint that matches the maple nicely in the problem area. I assume someone has done this before; any pointers? What color/type of paint matches maple closely?

Second, the back and sides are a wildly-figured mahogany. The sides bent fine, but at some point between bending and gluing the backplate in place, a 1"-long hairline crack developed in the upper bout of one of the sides, running perpendicular to the sides (i.e., from the soundboard toward the backplate). Wouldn't you know it --- I have braced the sides pretty well throughout, but this seems to be the in the middle of an unbraced area. Unfortunately, the wood has kinked out just a bit (maybe 1/64 - 1/32") where the wood began to crack. I'm assuming the appropriate remedy is a veneer patch on the inside supporting the cracked wood, and then sand the kink out of the outside as best I can. Does that sound right? Any other suggestions before I take this on?

Third, just a little further down the side from the crack (just a few inches from the neckblock), the sides have developed a bit of unevenness -- if I place a straightedge across the side (from the soundboard down to the backplate), the edge nearest the soundboard curves in a bit (maybe as much as 3/64" at the very edge). It's in a portion of the guitar where it won't go noticed by anyone but me, but it'll still bug me. How do you all approach this? Am I the only one that gets this kind of unevenness in my guitars? I'm guessing I will run the side of the guitar on the belt sander to even it out as much as possible, but I'm anxious to hear any other suggestions.

Author:  Michael McBroom [ Mon Aug 29, 2005 9:56 am ]
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Kelby,

I've run across the wavy side problem you mention, but so far it's only occurred when I've tried bending flatsawn sides. Now, whenever possible, I try to stick to quartersawn sides.

One way to get around this is, if you use a heating blanket and a bending mold, to construct a "female" section for the mold, so the side can be clamped down along the top and bottom. This will minimize the waviness.

I've also run into your purfling problem. To be honest, I hadn't thought of trying to paint in a line. I have some jewelers gravers -- kinda like short chisels. One of them is almost knife thin. With this thin graver, I can actually chisel out a very narrow channel, and then insert a piece of purfling. If you're looking for it, you can see the lines where the old and new purfling butt up against each other, but oh well.

As for your crack problem, I've had smaller ones that ran vertically like that. I just pushed Titebond into the crack and, using appropriate cauls, clamped the cracks shut, preserving the sides' bends in the process. This worked well, but then they wern't running all the way across.

Best,

Michael

Author:  Brock Poling [ Mon Aug 29, 2005 11:21 am ]
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I have repeatedly tried the "painting" idea you have mentioned with no success. Invariably it looks worse than it did originally.

What I would suggest is to take a very small bit and try to route an entirely new purfling channel. This too can be a bit dicey, but I have made it work. Presuming of course, that your sound hole isn't already cut.

As far as the wavy sides go. This happens to me too. I just sand everything flat and the curves fair before I cut my binding channels.

Good luck.Brock Poling38593.8486921296

Author:  RCoates [ Mon Aug 29, 2005 11:46 am ]
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For a cracked side I did the veneer patch inside and a inlay out side... Hopefully your inlay would be better than mine.


Author:  Kelby [ Mon Aug 29, 2005 12:27 pm ]
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You guys are awesome! Thanks much.

Brock, I sanded through the purfling line after the soundhole was already cut out. Doh! It really looks okay as is, so maybe I'll just leave it. The guitar is for one of my sons, and he'll never notice. (He's 9.) I'll chalk it up to experience, I guess.

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