another paint question

[bax]

I am doing the finish block sanding on the truck. How smooth is too smooth? I have sanded down to 600 grit and this puppy is starting to shine. have I gone too far, should I stop now or go to 1000?
Thanks

Bax

 

[1owner66]

I am not a painter but I think 600 should be fine. I didn't even know they made a 1000 grit. Just clean it off real good with air and then thinner, let it dry real good, and spray away.

 

[bax]

Thank you, any one else want to second that?

Bax

 

[sevenTseven]

http://www.autobody101.com/forums/

Got that link from another member, absolutely tons of paint/body information there.

Wish I could remember the guys name who originally posted it so he could have credit.

 

[allenfahey]

Start blocking with 320 to remove the orange peel and high spots, blocking will go faster. Guide coat again and continue with 400-500. After that use 500 on a da then a red scuff pad. Never use thinner before washing it, you can cause problems with the base coat. Use prep solvent

 

[byson1]

600 is the finest you want to sand before the top coat. Most shops stop as 320. You need something for the next layer of paint to "bite" onto and if it gets too smooth it won't adhere very well. You definately can get it too smooth. When I painted my Jeep (sorry) I did the final primer sanding with 400 just to be sure no sand scratches showed. Good luck.

 

[grant_71]

Stop at 600, i usually go to 500, Does not really matter. You will be fine.

The reason for 1000 grit and up is when you are wet-sanding after final clear or topcoat, it can be used to remove drips and small bits of dust. they go all the way up to 2000+ grits, then polish, then wax etc. That is how you get mirror finish hot rod sow shine....*sigh*

Grant

 

[Steve]

I would never finish sand before topcoat with anything finer than 400 wet. The paint needs some "roughness" to adhere to.

And they make stuff much finer than 1000 BTW, I have some 1600 at the house.

 

[bax]

OK I am going to stop at 400. I have a quarter panel and a door down to 600 at this time but I guess I can back up.
Thanks for all the advice, you guys are great.

Bax

 

[thegreatjustino]

Every experienced body man has his own way of doing things. Taking autobody classes at the local JC has been an interesting experience. The first instructor I had retired a couple of years ago and the new guy keeps asking me why I'm doing things the way the old instructor taught me to %) When I painted my Mustang, I dry sanded up to 220 then wet sanded with 320 and finally wet sanded with 600 before painting.

 

[allenfahey]

OK I am going to stop at 400. I have a quarter panel and a door down to 600 at this time but I guess I can back up.
Thanks for all the advice, you guys are great.

Bax

No matter what you stop at 400, 500, or 600 you should use a red scotchbrite before paint. If not some of the DA marks can show thru the base, so just red scuff the 600 panels when you do the rest of it.

Wet sand paper does get very fine, I use 3000 Trizact on a DA for buffing dark colors.