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PostPosted: Sun Jul 08, 2007 10:03 am 
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I am having a heck of a time trying to sand some flamed Koa sides. I have sent them through my sander, slow, fast, at an angle, stright in, super light passes, heaver passes, 80 grit and 100 grit, and every time, the "flames" in the Koa appear to darken. I had the same trouble with the back set too, but I was able to run the back through the sander at a 90* angle to the flame, and that fix the problem. The sides are too long to do that.

Any ideas?

Thanks

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 Post subject:
PostPosted: Sun Jul 08, 2007 10:29 am 
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Koa
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Scraper?

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PostPosted: Sun Jul 08, 2007 10:47 am 
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Brazilian Rosewood
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Lance, when I do koa the sanding process does seem to make the curl a bit darker and more pronounced, its normal..... don't worry about it. Did you see my koa guitar? thats how it went.

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 Post subject:
PostPosted: Sun Jul 08, 2007 11:14 am 
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Hesh, here is how it looks.





Here is how the back came out.



Peter, I dont recall seeing this on your guitar?

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PostPosted: Sun Jul 08, 2007 11:17 am 
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Cocobolo
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Fresh abrasive will help.
Sharp abrasives generate a lot less heat.

Mark






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PostPosted: Sun Jul 08, 2007 11:19 am 
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Thanks Mark, I tried 80 and 100 grits, both brand new.

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PostPosted: Sun Jul 08, 2007 11:22 am 
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Koa
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Lance, your sides look normal to me. The back is cut from a very different tighter fiddle back figure and your "dark" bands are there, but much narrower and deeper. The side grain undulations (what makes curl) are much broader and reflect back wider of course. Looks like you have some other broken curly figure going on also which might be causing the splotchy look, but it is "figure". Doesn't look like any of the wood is "scorched" at all.


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 Post subject:
PostPosted: Sun Jul 08, 2007 11:27 am 
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Thanks Larry,

I will plow forward!

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PostPosted: Sun Jul 08, 2007 11:48 am 
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Brazilian Rosewood
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[QUOTE=LanceK]

Peter, I dont recall seeing this on your guitar?[/QUOTE]

It looks different after the finish is applied!   

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Cornerstone Guitars
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PostPosted: Sun Jul 08, 2007 12:19 pm 
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Brazilian Rosewood
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Everytime flame starts to darken/scorch it's always past due for some new
abrasives.... Hard to say for sure that's what's happening here though fresh
sandpaper wouldn't hurt, and light passes will build up much less heat.

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 Post subject:
PostPosted: Mon Jul 09, 2007 2:48 am 
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See if it cleans up with a random orbital. I always sand to a scratch free texture right after I thickness backs, sides and tops and before I do any further processing. It saves much time and produces a much nicer finish after everything is put together. Then the pre-finish sanding is so much easier.

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