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Is 320 too coarse for sanding clear flat?


Trying to be the best me, I can be
Couple more of my pennies....:) Anyone reading this, If you are new to this and thinking about doing 320 to get the "Look" JC was talking about, Don't. It takes far more than just the sand before you reclear to get something arrow straight. If you are new to this, sorry your car isn't going to look like what he was describing. It takes years (sometimes) of experience to get to that point. And it's so much more than just the clear coat sand before re-clear. There are so many threads and posts on here where someone was color sanding and sanded through. If you use 320 you will sand through or your clear will be so thin that it's kinda pointless to have done it in the first place. 600-800 by hand wet will work great and give you the experience of doing it and (hopefully) not sanding through. With 320 its not a matter of if, but how many places will you sand through? Get the experience of doing it and not making any major boo-boos and concentrate on making the next job better than your previous one.
I agree with Chris (above)
And like I said, 600 to 800 grit gave such good results most people couldn't see a difference.
And I did my comparisons dry sanding.
One more question. What’s the difference in sanding dry verses wet? I know wet helps keep paper clean, but what are the other differences or advantages with one verses the other.
I’d also like to thank all of you for taking the time to help me by giving me advice.
I live by the motto, “ A wise man learns from others mistakes, a fool from his own.” So I value what im told.
I like dry and wet for different reasons.
One good thing for dry is when it's cold and not having to deal with the wet and the sludge
it generates, especially in the winter in my garage. it's much cleaner.
I can also see where I've sanded and how much I've sanded a little better with dry.
But mostly everyone has their own personal preference, you need to try both and decide.

Also, here's a picture of a hood I did recently initially sanding with 1500 grit
with a 6" random orbital sander, then 2000.
It's not "dead straight" but the reflections clearly show the amount of wave left in
the paint, quite minimal I think. This is as good as I will do for my normal collision repair work.


I’ve done several repairs on daily driver modern cars. And usually just de-nib and buff.
But like I said this car is for show.
Here’s a pic of a door I did. This is after the first 3 coats of clear, hasn’t been sanded and re-cleared yet. E165BF92-430A-4E3B-B8AA-FAD84F91F0D3.jpeg
I agree that dry sanding and wet sanding have their individual places.
This hood was dry sanded first with a DA and 1000 just to remove orange peel. Then I used 1000 grit wrapped around a piece of Oak and wet sanded as described above to get it flat. Back to the DA and dry sanded with 1500, followed by 2000.


This was 5 coats of UC. I am a sucky painter so I had lot of orange peel so I used 500 wet on a short Durablock to get the peel and flaws out then 1000 wet using a 3M squeegee as a block then 1500 on a DA sander. Buffed with CSI and wool then CSI with foam. The "waviness" is the orange peel in the base coat. I actually like this effect on these old classics. As you get to a sharper angle you can see that the clear is very flat. 46397964_2010996782269562_2222924258927968256_n.jpg

Only because that was all I had at the time (I live 50 miles from the nearest urban center). I should have had an intermediate step because if you look at it in the light just right you can see some of the 500 scratches that are not quite out but the color is so light you have to work to see them.
To me it depends on how much peel you are dealing with, and also consider your time. You can most probably use 320 to cut thru the most of it (stay away from corners and edges) and then use the recommended 400. There is no reason to spend 10 hours blocking with 400 when you can go over the entire car in 2 hours with 320 then put the right scratch that the manufacturer wants in another hour since all the bad stuff is out of the way.