Wetsanding clear with 400

5

540goat

I have some orange peel and dirt in my clear. I only have 2 coats of clear on the car and I am going to do as the perfect paint job say and wet sand with 400-800 and then put 3 more coats on the car. I am assuming the clear will fill in the 400 grit sanding marks. I tried 600 but it will take forever to get the panels flat, 400 does a much faster job.
 
With only two coats of clear you will have a much greater risk of sanding through with 400. In my copy of the perfect paint job I believe it was 3-4 coats of clear then wet sand and shoot 3 more coats. I say 3-4 coats on the first round because of the way the article is written (first, second then fourth coats are referenced with no mention of a third) but 3 wet coats would be a minimum IMHO.
 
It would be reckless for anyone who hasn't seen the finish to recommend 400 grit. You might get away with it, or you might not. If you really want to try it, stay off edges and body lines, use 600 in those areas.
 
The 400-800 in the perfect paint job write up is meant to be a range of grits within which to choose from and not the suggestion of starting with 400 and working to 800 if that's how your reading it.
Had you hosed on three coats of clear then 400 would be the choice to knock down the wave and get the panel flat but if you only have 2 light to medium coats my guess is you will sand through.
 
i wouldn't even walk past 2 coats with 400. 600 would be bad enough. your gonna burn it,,,,,,,
 
[QUOTE='68 Coronet R/T;13214]The 400-800 in the perfect paint job write up is meant to be a range of grits within which to choose from and not the suggestion of starting with 400 and working to 800 if that's how your reading it.
Had you hosed on three coats of clear then 400 would be the choice to knock down the wave and get the panel flat but if you only have 2 light to medium coats my guess is you will sand through.[/QUOTE]

I wasn't going to go from 400 to 800. I was just going to go with one of the grits. The coats were pretty heavy, I tried an area of the car this morning and the 400 seemed to be O.K..
Just used a fresh piece of 600, worked just as good. I will play it safe and just go with the 600 for now.
 
I don't know what color you used, but be very careful of sanding the clear and hitting the base. There is a thread I started about repairing base that is hit when sanding thru clear. It can make for some real headaches.

That being said, obviously I cannot see how bad the OP is, but there are safer ways to fix it. If it is real bad, you could simply scuff the clear and shoot a couple additional coats on as sacraficial material. That way you could safely sand with say 800 or 1000 to get it flat with less chance of hitting the base. You could also take 800 or 1000 and try to knock down some of the OP before shooting more clear to make it a little smoother for the next sanding session. If you use the slower activator it may actually lay out pretty good over the OP that is left.

Trying to use 400 for clear is just too risky specially over 2 coats.

Just my opinion.... then again I screw up regualrly.

Aaron
 
ADTKART;13228 said:
I don't know what color you used, but be very careful of sanding the clear and hitting the base. There is a thread I started about repairing base that is hit when sanding thru clear. It can make for some real headaches.

That being said, obviously I cannot see how bad the OP is, but there are safer ways to fix it. If it is real bad, you could simply scuff the clear and shoot a couple additional coats on as sacraficial material. That way you could safely sand with say 800 or 1000 to get it flat with less chance of hitting the base. You could also take 800 or 1000 and try to knock down some of the OP before shooting more clear to make it a little smoother for the next sanding session. If you use the slower activator it may actually lay out pretty good over the OP that is left.

Trying to use 400 for clear is just too risky specially over 2 coats.

Just my opinion.... then again I screw up regualrly.

Aaron
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I painted the car solid red, SPI red. There are a few runs and some dirt. Nothing bad. I was just curious with the 400 mentioned I thought it would be a little harsh.
 
wet sanding

Shine, what do you mean by taping over the runs? I have taped out side of them to lessen the chance of sanding thru and do use a coarser paper till most of the problem is gone then back to 1000.
 
i put a piece of 2 in tape over it and sand through the tape. cuts just the run , nothing else .
 
shine;13242 said:
i put a piece of 2 in tape over it and sand through the tape. cuts just the run , nothing else .
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Great tip, thanks.

Question, I don't have any runs, but do have dirt in the clear, should I do the same, put tape over the dirt spot and sand through?
 
You shouldn't need tape for just typical dirt, you shouldn't have to sand so much that you will have to worry about going through.

I may have to try this run trick sometime too.
 
I tried the tape trick and it works OK for knocking off the majority of the run. Definitely use a block.
 
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