Traveler Posted February 3, 2008 Report Share Posted February 3, 2008 I'm finishing my neck hs and am at the clear stage after sealer, primer, blk nitro, initial 4 coats of clear, blocked with 600G wet with spirits for peel removal/leveling....wipe down with naptha, tack, warm up can as before then shoot. What I have is clearly visible sanding scratches and a grey effect from blocking the previous clear coats and the resulting matte grey is now present and doesn't appear to be fixed by more coats of clear. I'm using Stew mac aresol nitro which seems to spray pretty nice when warmed a bit and no issues until now. I'm following a paint tutorial by Dan E. off their site on using the aresols by color coats then 4 coats clear, block if needed, then 4 final coats then wait and final block and polish. anyone exp. with finishing know what happened and advice would be appreciated. I think I need to sand back thru the recent 5th coat to the blocked surface and either polish it out further for more clear or see if those 4 coats will take a final block and polish and just live with it. If it still looks like ****, I'll just lay on another coat of black and go from there. Quote Link to comment Share on other sites More sharing options...
MiKro Posted February 3, 2008 Report Share Posted February 3, 2008 I'm finishing my neck hs and am at the clear stage after sealer, primer, blk nitro, initial 4 coats of clear, blocked with 600G wet with spirits for peel removal/leveling....wipe down with naptha, tack, warm up can as before then shoot. What I have is clearly visible sanding scratches and a grey effect from blocking the previous clear coats and the resulting matte grey is now present and doesn't appear to be fixed by more coats of clear. I'm using Stew mac aresol nitro which seems to spray pretty nice when warmed a bit and no issues until now. I'm following a paint tutorial by Dan E. off their site on using the aresols by color coats then 4 coats clear, block if needed, then 4 final coats then wait and final block and polish. anyone exp. with finishing know what happened and advice would be appreciated. I think I need to sand back thru the recent 5th coat to the blocked surface and either polish it out further for more clear or see if those 4 coats will take a final block and polish and just live with it. If it still looks like ****, I'll just lay on another coat of black and go from there.Traveler, Hard to say, A pic would help. What's the temp and humidity like at the time of spraying? So many varibles. So really A good PIC would help someone work through this and help. MIke Quote Link to comment Share on other sites More sharing options...
MiKro Posted February 4, 2008 Report Share Posted February 4, 2008 (edited) Okay Traveler sent me a pic so here it is for all to see and digest the problem. at time of this post I have not studied the photo. link to another pic Mike Edited February 4, 2008 by MiKro Quote Link to comment Share on other sites More sharing options...
Twoods196 Posted February 4, 2008 Report Share Posted February 4, 2008 I Paint cars and this may be diffrent than cars but we never wet sand clear coats between coats and If we would have it def. wouldnt be with 600G. At the least 1000g or 1500G Wet. We apply all coats of clear then wet sand with 1500g until all orange peel is gone then buff at 3000rpm with a 3m 3in1 Compound. Quote Link to comment Share on other sites More sharing options...
ihocky2 Posted February 4, 2008 Report Share Posted February 4, 2008 I can see the scratches but I don't really notice any gray tones from the wet sanding. If it does have a grayish tint, that could be from dyes releasing from the sandpaper while wet sanding with mineral spirits. Not very common, but it does happen occasionally. You may be getting the gray tone though from light refraction off the sanding scratches. How many clear coats have you sprayed since you sanded? If it is only one coat, you may want to spray another coat. I have had it take two or three coats to really get sanding scratches to melt away from a level sanding. Especially depending how heavy you are spraying on. A light coat won't melt the scratches away as well. Quote Link to comment Share on other sites More sharing options...
Traveler Posted February 4, 2008 Author Report Share Posted February 4, 2008 I can see the scratches but I don't really notice any gray tones from the wet sanding. If it does have a grayish tint, that could be from dyes releasing from the sandpaper while wet sanding with mineral spirits. Not very common, but it does happen occasionally. You may be getting the gray tone though from light refraction off the sanding scratches. How many clear coats have you sprayed since you sanded? If it is only one coat, you may want to spray another coat. I have had it take two or three coats to really get sanding scratches to melt away from a level sanding. Especially depending how heavy you are spraying on. A light coat won't melt the scratches away as well. I was thinking the same thing about the refraction, that pic is after the 2nd coat applied after leveling the first 4. the coats are applied moderately wet, no runs but I error on the dry side, the reason for the peel that needed leveling. I'm going to take it back to the 'leveled' coats add a couple color coats and go from there. I can't see this stuff going away by melting in with the graying effect. It's hard to get it to show in a pic but it's not subtle in person. thanks Mike for posting the pics for me, and all the responses. Quote Link to comment Share on other sites More sharing options...
MiKro Posted February 4, 2008 Report Share Posted February 4, 2008 >snip< thanks Mike for posting the pics for me, and all the responses. You are welcome, glad to help, MK Quote Link to comment Share on other sites More sharing options...
Dudz Posted February 5, 2008 Report Share Posted February 5, 2008 To me it looks like you didn't sand with a fine enough grit of sandpaper you should really go up to really fine grits like 1000 and 1500 like twoods said. Quote Link to comment Share on other sites More sharing options...
Mattia Posted February 5, 2008 Report Share Posted February 5, 2008 I never sand finer than 600 grit between coats of paint, and it has zero effect on visible scratches; subsequent coats melt in and hide them completely. Thing is: never, ever, ever scuff sand colour coats, and only scuff sand once per day (every 3-4 coats), lightly. I also do a full level right before a final coat or two, and then start with 1500, sometimes 2000 grit and go to polishing from there. Quote Link to comment Share on other sites More sharing options...
Traveler Posted February 6, 2008 Author Report Share Posted February 6, 2008 I never sand finer than 600 grit between coats of paint, and it has zero effect on visible scratches; subsequent coats melt in and hide them completely. Thing is: never, ever, ever scuff sand colour coats, and only scuff sand once per day (every 3-4 coats), lightly. I also do a full level right before a final coat or two, and then start with 1500, sometimes 2000 grit and go to polishing from there. I did a light leveling in the last color coat with 1000, and the first 4 clear coats went on melted in and looked good, this graying effect happened after I did another leveling of the first 4 clear coats then appeared in #5-6. I expected of course for the succeeding post leveling clear coats to do what the first 4 coats did after leveling the color coats and lay on nicely. almost a week now and no visible change in appearance, gonna redo I guess. Quote Link to comment Share on other sites More sharing options...
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