verhoevenc Posted January 12, 2006 Report Share Posted January 12, 2006 Alright... this is NOT cool! I was using some really hi-grit sandpaper to do some sanding. For some reason, paper changes color from normal sand to black, or something darker as the grit reaches like the 300 area... atleast in the brand I use. However, When I just sanded some of my spruce today up to 600 grit, it left parts of the grain black?!?! Almost like I had stained it black, and then sanded back... or like if I had black grain filled (even though the spruce doesn't need grain filling,,, but you get the idea). How do I get this black out?! -Water (but wouldn't that raise the grain and defeat the sanding I just did?) -Mineral Spirits? (does that raise grain too?) -Re-sand? (but it's already kinda thin....) Any help would be awesome, Chris PS: It didn't do this when I did the EXACT same procedure yesterday? Quote Link to comment Share on other sites More sharing options...
Gorecki Posted January 12, 2006 Report Share Posted January 12, 2006 It almost sounds as if you didn't get the scratches from the 300 out totally and are filling with paper dust. Have you tried, cleaning/tack cloth to see if it's just crud in the scratches? Just a thought. Quote Link to comment Share on other sites More sharing options...
unclej Posted January 12, 2006 Report Share Posted January 12, 2006 if you've got a compressor you should be able to just blow it out of the grain.. Quote Link to comment Share on other sites More sharing options...
Biz Posted January 13, 2006 Report Share Posted January 13, 2006 Check on this, but i have heard turpintine is what antique restorers use for cleaning grain. im curious why you were sanding that fine in the first place because your finishing procedure will need something around 180-220 to grab on to. Quote Link to comment Share on other sites More sharing options...
Gorecki Posted January 13, 2006 Report Share Posted January 13, 2006 Quote Link to comment Share on other sites More sharing options...
Gemm012 Posted January 13, 2006 Report Share Posted January 13, 2006 What is the bad advice? Galen. Quote Link to comment Share on other sites More sharing options...
guitar2005 Posted January 14, 2006 Report Share Posted January 14, 2006 What is the bad advice? Galen. Turpentine. Quote Link to comment Share on other sites More sharing options...
erikbojerik Posted January 14, 2006 Report Share Posted January 14, 2006 Are you sure this isn't dark-colored dust from sanding some other kind of wood with the same sheet of paper? Either on the guitar, or some other piece of wood? Quote Link to comment Share on other sites More sharing options...
verhoevenc Posted January 14, 2006 Author Report Share Posted January 14, 2006 nope, it was a BRAND new sheet Chris Quote Link to comment Share on other sites More sharing options...
Gemm012 Posted January 14, 2006 Report Share Posted January 14, 2006 What is the bad advice? Galen. Turpentine. Ok, cool. Thanks. Galen. Quote Link to comment Share on other sites More sharing options...
LGM Guitars Posted January 15, 2006 Report Share Posted January 15, 2006 180 to 220 for a finish to grab onto huh? Riiiiiiiiiiiiiiiiiiiiiiiiight, there's some more of that great advice. Even solid color paint will show those scratches, if I'm doing a solid color guitar the body is sanded to 600 before paint, if it's a transparent finish it's taken to 1000 before paint or the sanding scratches WILL show. I have no idea why sandpaper would be leaving black marks, I really don't, is it REALLY cheap hardware store sandpaper? Try blowing all the grain out with compressed air as was mentioned. Then get a better sandpaper and resand it, hopefully it's not TO thin. Quote Link to comment Share on other sites More sharing options...
Biz Posted January 15, 2006 Report Share Posted January 15, 2006 It appears that i may have given bad advice as stated from above, of course i was totally unaware i can assure you. I know Ive seen the restorers use turpentine. Perhaps Gorecki or someone can explain to us all why it is not suited for bare wood. Some searching showed it is used mainly for cleaning "finished" wood. Some used it for cleaning wax residue from bare wood before refinishing. This link exposes another opinion that naptha is the best "bare" wood cleaner. http://www.guitarspecialist.com/q&a.htm I also seen that using a white 'not red' eraser is good to clean pencil lead and dirt from carvings before finishing. Never practice on the real thing. Quote Link to comment Share on other sites More sharing options...
Primal Posted January 15, 2006 Report Share Posted January 15, 2006 I throw in a plug for 3M Sandblaster sandpaper... amazing stuff. Quote Link to comment Share on other sites More sharing options...
Gorecki Posted January 15, 2006 Report Share Posted January 15, 2006 naptha is the best "bare" wood cleaner. Sorry, missed most of this..playoff's ya know. Naptha is great for wood. Otherwise, I agree with LGM, the paper is fragmenting like mad and/or scratches are filling with dust or...something Quote Link to comment Share on other sites More sharing options...
Mickguard Posted January 15, 2006 Report Share Posted January 15, 2006 I ordered the sample pack of fre-cut sandpaper from Stewmac a while back. And I gotta say, it makes a HUGE difference over the stuff I get at the hardware store. An infinite difference. I still use the hardware store stuff for the coarse work. But when it's time to get fine (starting at about 180- 220 that is), I switch to the Stewmack pack. And I only use the Stewmac papers for wet sanding. Quote Link to comment Share on other sites More sharing options...
dunbarhamlin Posted January 20, 2006 Report Share Posted January 20, 2006 if it's a transparent finish it's taken to 1000 before paint or the sanding scratches WILL show. Not only scratches, but I've found for a clear finish, taking up to ever finer grits brings out that wonderful spruce cross grain pattern far stronger than just applying a finish can do - (I expect) the same would be true of some hardwood figures (?) Quote Link to comment Share on other sites More sharing options...
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