Sanding marks showing through clear

[carlini]

Did a flamejob, black base with yellow to orange flames. Base cleared the flames with orange pearl in the basecoat clear, then unmasked the flames. So far everything cool. Cleared the whole job,wetsanded the clear to smooth out everything, used wax & grease remover over wetsanded job, then recleared the whole job again. Wetsanded whole job again, wheeled it out & it looked great, until closer inspection in sunlight! Under the sun you could see the wet sanding marks from wetsanding the first overall clearcoat application. I thought for sure the second clearcoating would hide these wetsand marks, but they showed through. any solutions so this won't happen again on a black basecoat job will be appreciated!

 

[flamethrower]

What grit paper did you use wet? I have heard guys using as course as 600 wet with no problems, but I never use anything rougher than 2000 wet. I ain't gonna risk all that work on a chance you can see the scratches. Also, you might just sand out the runs and then use a maroon or gray scotch brite pad on the rest of the clear.

FT

 

[rex]

Yeah,what grit did you use?Can you see the scratches thru the clear and all over or not,or is it final sanding scratches that weren't cut completely out?

 

[kvan]

Originally posted by carlini:
Did a flamejob, black base with yellow to orange flames. Base cleared the flames with orange pearl in the basecoat clear, then unmasked the flames. So far everything cool. Cleared the whole job,wetsanded the clear to smooth out everything, used wax & grease remover over wetsanded job, then recleared the whole job again. Wetsanded whole job again, wheeled it out & it looked great, until closer inspection in sunlight! Under the sun you could see the wet sanding marks from wetsanding the first overall clearcoat application. I thought for sure the second clearcoating would hide these wetsand marks, but they showed through. any solutions so this won't happen again on a black basecoat job will be appreciated!

<font size="2" face="Verdana, Helvetica, sans-serif">Try using a finer sandpaper like 2000 or 3000 grit sandpaper

 

[Austin]

2000-3000 grit scrates will be way to fine to "hold" 2-3 wet coats of clear. I recomend 600-1000 grit no finer or coarser. I usually use 800 on a DA, for a re-clear.
Austin

 

[flamethrower]

Austin, if you can use 800 on a DA and not bust thru anywhere, my hat's off to you. I would never do that. And I have had no problems holding even 6 coats of clear using the 2000 wet before the first three and then between the first three coats and the last three coats of clear.

 

[patsnitrovette]

i had the same problem a few years back,i sanded the clear with 600 then sprayed 3 more coats of clear,and then sanded and buffed,but i could see the sanding marks under flourescent lights.So if wouldve sanded with 2000 or 3000 it wouldve been ok and clear still held ok?

 

[thimmesch1]

I also use 800 on a da with a soft interface pad.... no problem....

 

[Jim]

Wetsand with 2000 and buff it with a micro finish like perfect it or something similar,then swirl mark remover,and finally hand glaze,you'll be amazed how much a buffer removes,if not then it's time to reclear.

 

[carlini]

The first clearcoating was sanded with 800 grit, then washed down with wax & grease remover, then recleared. I'm thinking the parts should have been washed with mild detergent & water, then dried, then washed down with wax & grease remover. The wax & grease remover does not desolve water soluble substances. The sanding marks showing through might actually be sanding residue from sanding the first clearcoating,becoming lodged in the microscoptic grooves created by the 800 grit. Seems possible to me. Also perhaps the clear needed to be thinned down a little more. Maybe the second clearcoat was too thick to sink into the microscopic grooves created by the 800 grit. Instead of the clear melting in with any left over clear sanding residue from sanding the first clearcoat, it possibly bridged over the sanding gooves instead of sinking to the bottom of them and filling the grooves. Geez, maybe I just answered my own questions, but after giving the problem much thought, these answers seem logical to me. How do they sound to any of you experienced painters out there?

 

[rex]

Unless the clear was extremely thick like stucco it shouldn't bridge the scratches.The residue sounds like the culprit.Always wash the part with water if only clear is going over them,even if it's just a damp rag followed by a dry one.I use 800 on a da also.DA paper is coarser compared to wet paper in the same grit,just FYI in case you want to hand sand with a piece of DA paper.Norton's champaigne DA paper can be used wet and won't fall apart like 3M does but my 800 this way is closer to 600 wet paper.

 

[Austin]

Flamethrower, I use 800 on a DA everyday, without breaking through often. It does happen on ocasion, but not to often. Then again I do this for a living, so I've learned when to stop sanding.
Austin

 

[flamethrower]

Austin,
That's cool, I just do it as a hobby and don't have that much experience. I learned early on that a little pressure with sandpaper goes a loooonnnggg way. I learned this the hard way, of course. I'm sure with the right touch rougher paper can be used... I just don't have the right touch. But I still haven't had a problem "holding" my topcoats on while using 2000 wet between shoots.

Thanks for the follow up.

FT

 

[FLAME QUEEN]

Now now Guys ,
the way I read this was that under good hounest
light the sand scratchs could be seen though.. the clear and my guess is the scratchs are evident meaning thier there be fore the clear and poss. at the start.
Its a hard one to swallow , but its a fact it happen to the best of us at least once ,????
How do like this god given riding weather WOw and Man

 

[FLAME QUEEN]

Hay Carilini when you really think youv'ed ansered it for your self and find you still can't seemed to get it please come on in and join this party!!!