Thread: Finish sanding

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I have a 62 Galaxie and very close to applying the base color. Just wondering if 600 grit is ok before spraying base, and should the base be sanded before applying the clear?

i sanded up to 600 before base when i did not use a sealer .from time to time i had to sand the base. with some of the paint i used . that was not good to do with out another top coat of base.if you want to sand before clear i would go to a single stage paint sand out with 1000 and clear

I like to use 800 wet sand if I'm spraing metallics without a sealer. 400-600 works well on solid colors or single stage. I'll back up what Pat said. Don't sand base coat before applying clear. you can sand out little nibs of trash but you have to apply more base over the area before applying the clear. You will be able to see the cratches if you don't. I like to clear over single stage also. I like to let cure, sand it with 1000 or maybe 2000 if there's not a lot of texture, then clear over it. Just keep in mind you are putting a lot of material on the surface so don't get too crazy with the number of coats. You don't want it too thick. We did a Black '40 Ford that way and the clear layed down so flat we only had to spot buff a couple of trash spots and the car looked awesome. The customer was well pleased and the car had nearly no texture so no reason to buff it.

i have seen guys sand out solid color with 600 grit and go to clear. the new yellow back 3m paper is much coarser then the old 3m paper that is what i used .if you use the yellow back it would be much finer like 800. for blending i sanded to 1000 no need to go any finer you could loose hook up on the clear . for black paint i have done many black paint jobs. i still like them with no clear on them . throw down 3 to 4 coats sand dead flat put down 2 more coats . the last black job i did was on a new chevy truck . the guy did not like the clear look shot it in ppg dau 9300(showing my age ) in a factory pack paint not mixing bank black is weaker black. my chevy is just dau. i love it guys always ask .wow man how many coats of clear ?? none

i will add this if you must sand your base try to roll the paper up so you cut no tracks in the base if you do you have one hell of a time getting them OUT do not ask how i know that .. the paper will plug up fast as well. i think i use ppg 330 not water but it been a long time ? i know i did sand the dps with 330 when needed. DO NOT USE 440

Finish the primer with 600-800 (I use 800 personally but it's not always needed) and then spray your base and follow up with correct flash time and lay on the clear. If you get trash in the base, wet sand it, spray your color on that spot and continue to the clearing. If I am painting over a vehicle that has it's original paint or may have spots on it that I am not sure will cover or cause problems with the base then I will highly reduce SPI Epoxy primer (acts as a sealer) and put on a very light sealer coat, let it dry for about an hour and then proceed with the base coat.
Good luck!

Pat, Have you tried scuff gel? We used to sand for blending but we started using scuff gel and the gold scuff pads and we'll never go back. We've been using it 4-5 years now I think. I remember at a paint school once a dupont rep said to soak the yellow backed paper in water a while before using it which would soften it up a bit, you ever heard that? I tried it and it seems to help a bit. I've had problems with metallics standing up in the sand scratches, silver to name one, when I used to prepare the panel with paper before blending. The scuff gel helped that problem.

Originally Posted by 35chevy

Pat, Have you tried scuff gel? We used to sand for blending but we started using scuff gel and the gold scuff pads and we'll never go back. We've been using it 4-5 years now I think. I remember at a paint school once a dupont rep said to soak the yellow backed paper in water a while before using it which would soften it up a bit, you ever heard that? I tried it and it seems to help a bit. I've had problems with metallics standing up in the sand scratches, silver to name one, when I used to prepare the panel with paper before blending. The scuff gel helped that problem.

no i was getting out of the body work full time when the gold back paper was coming out and the junk 3m green tape.the soak in water deal works on the hard back paper and i did for cut and buffing paper 1000 and up .but the 400to 600 yellow back to me is just to coarse. for blending i used 800 on a da and then wet sanded to 1000. or some times just sanded it with 1000 no da with 800. that had a lot to do with how big of a blend on a car with lets say a fender i blend the hood the door and cleared the hole side of the car if the front door needed work i push paint in to the next panle we called them 5 mile blends

Thanks for everyone's input. Now it's time to block the car one more time, to check low spots.

Not sure if this will help but in the U.K. the unwritten rule is 600 for straight paint and 800 for clear over base.

We used 600 to wet sand the primer on my sons Firebird; (black base /clear) and it turned out really nice. It was mostly plastic and 'glass body panels; not sure if that makes a difference or not.

800 to600 or 400 has alot to do if your sealing up the prime or painting on the primer with no sealer some of the sanding paper seams that it is abit coarser .on every day work at the shop i was at was 320 d.a then using the 3m gray back wet dry paper 400to600 the jobs that i wanted dead flat base i tinted the last coat of primer and sanded it out to 600 and shot base right on the primer

I've seen folks use 320/400 for final sanding, but I use 600 then do a final with 800-1000. I stopped using 3m paper for exactly the same reason Pat stated and went to either Norton or Mirka($$). For whatever reason, 3m has changed their manufacturing processes and it doesn't hold up.

A trick or two, tear the paper rather then cut it (fold towards the grit first then tear), another, soak the paper for about 30 minutes in a half bucket of water with a little squirt of Dawn dish detergent, then use a spray bottle with some of that kind of mixture to keep the surface wet while you sand. To me, it works slick!!!

I have sanded BC but you do chance making thin spots that show through, especially grays and silver (of course there can also be tiger stripes in those colors as well)

Do you guys over there not tint your primers body colour ???

Originally Posted by pat mccarthy

800 to600 or 400 has alot to do if your sealing up the prime or painting on the primer with no sealer some of the sanding paper seams that it is abit coarser .on every day work at the shop i was at was 320 d.a then using the 3m gray back wet dry paper 400to600 the jobs that i wanted dead flat base i tinted the last coat of primer and sanded it out to 600 and shot base right on the primer

Originally Posted by roadster32

Do you guys over there not tint your primers body colour ???

Speaking only for myself, light, medium or dark depending on the BC or SS