Sand Primer Berfore Paint?

[CRAZYBOB]

Just wondering if you used Rustoleum High Build Automotive Primer. Would you then sand the primer before applying the color? If so what grit paper would you use? Do you need to wipe down the primer with anything before painting? Thanks.

[Jack FFR1846]

You would want to do a final block out of the primer to get it flat. I'm pretty sure I stopped at 600 for primer. And yes, you will want to clean the whole car. I used a prepsol type solvent first and then several times with water to pull any residual solvent out of the surface. Then, you do need to dry it thoroughly.

[CRAZYBOB]

Ok, I guess my concern was the paint having something to "bite" into. So 600 is not to smoothe?

[mrmustang]

Just wondering if you used Rustoleum High Build Automotive Primer. Would you then sand the primer before applying the color? If so what grit paper would you use? Do you need to wipe down the primer with anything before painting? Thanks.

Rustoleum makes an automotive paint?

Yes, you will sand the primer smooth, then wipe down a low grade, high evaporation cleaning solution, then wipe down with a tack rag.


Bill S.

[Mustang Man]

High build primers are generally used to cover/hide filler and are designed to be block sanded down to smooth using anything from 80 to 400 depending upon what you're topcoating with. High build has its place, but a sealer type primer is best to ensure the surface, no matter what it is, is properly sealed for the base coat. Something like PPG DPLF primer can be used as a sealer (and it isn't sanded) and then top coat right after.

HTH...
Mark

[CRAZYBOB]

HMMM... Thanks for the info.. So, I guess I was hoping not to hear this though. So, is it possible to paint over the high build primer? Or do you have to use sealer primer? I am using Eastwood Single Stage Urethane Rat Rod flat black (satin black). I sure don't feel like sanding again.. But if I have too........

[Jeff Kleiner]

I suppose you don't have to sand a high build primer but it's whole purpose is to put several mils of material down so that you can block it out slick and smooth. You'd have a pretty rough finish if you went directly to paint without saanding. Sealer is always a good idea but not absolutely necessary as long as you have complete coverage of all substrates with your primer. You won't want to hear this either but unless you are darn good with a gun you'll probably need to sand your sealer to make it slick and flat also.


And yes, you will want to clean the whole car. I used a prepsol type solvent first and then several times with water to pull any residual solvent out of the surface. Then, you do need to dry it thoroughly.

Sorry Jack, I have to disagree NO WATER OVER PRIMER! It is pervious and can allow moisture through and into fillers below. You might think you have it dry but unless you can leave it for an extended time or cook it in a booth you run the risk of it lying in wait ready to bite you in the a$$ when you paint! On the other hand catalyzed sealers are impervious and can be exposed to water.

Good luck,
Jeff

[riptide motorsport]

Listen to Jeff he answered all your questions...........Steven