Just finished a car with single stage Omni acrylic urethane. What is a normal time to wait to begin wet sanding buffing this paint? Any recommendations on beginning grit? Not very experienced at this.

Follow the tech sheet cure time before sanding - but generally after a day would be safe for pretty much any paint.

Start with 1000 grit, wet sanding. If you search this site for topics on cut and buff or buffing you should find tons of threads about this.

Thanks Chris - I will have to round up some 1000 grit...all I have on hand is 1500. Going to give it a go on the hood in the morning.

you're welcome; also - if that paint is metallic then either do not sand it or try it first on an inconspicuous area -- since you can shear off the metallics when sanding a SS metallic paint job. You will see this as tiny white "dots" in the finish, since the sandpaper is literally cutting the metallic particles.

If in doubt, check the tech sheet or call the tech support line for the paint you are using.

on light colors, you can scuff with some grey scotchbright and then rub some powdered guide coat on and sande till its all gone, it takes the guess work out of how much paint you have sanded back!!
krem

Never heard of using guide coat on the paint. Should be really easy to see where you've sanded with go lighting since there will simply be shiny spots where there texture is not completely flat.

well when you thnk about it, your simply doing the same to your paint as you are your primer, you want it smooth and coarse scratches out of it, the guide coat will allow you to see how much you've taken off with out having to dry the paint off and look for shiny bits that you missed!!
try it, it works great!!
krem

The main problem I have with this idea krem is that you are adding abrasives to the sanding process which may be a problem. I don't since I've never tried it, so your experience would help us all gain knowledge on that. Thanks for any further input you can give.

The concept is simple but successful execution depends on being able to scuff evenly over the whole area. By putting scratches in the surface and then filling those with guide coat you'd have a pretty good visual indication of when you've gone far enough. One thing that bothers me is that doing it with 2K is a bit more dangerous than with COB. 2K is generally much thinner than clear, so you don't have as much to work with.

i have done it a few times now and so far no probs, I use a soft furry brush headon my vac to get rid of the excess powder from the guide coat before I start my sanding,
depending on how much material I put on and the peel, I would start off with 1200, then guide coat again, then 1500 and same with 2000, after the 1st color sand you are taking off verylittle material and it moves along quite fast.
I the finish off with a foam 3000 disc on my orbi on the fine orb setting, takes very little effort to get the shine up.
I actually got the idea from a dvd specifically showcasing color sanding and buffing.
krem