Start over or touch up?

While sanding down the colour coat I sanded through to the primer - and perhaps the base plastic - on the edges. Should I strip the car and start from scratch or just spray the areas I sanded too much and then do a couples of full overall coats?

That depends. I can think of situations where either would be appropriate.

How about some details?

While sanding down the colour coat I sanded through to the primer - and perhaps the base plastic - on the edges. Should I strip the car and start from scratch or just spray the areas I sanded too much and then do a couples of full overall coats?
What type of paint did you use? What color is it? What color is the bare plastic?
Most of the time if its a more opaque color I just go for the fix it route... if the fix looks ok then I'll leave it at that. The trick I use is to touch up the whole panel.
You say that you sanded through the edges... just a few little places? or how much?

i suggest you take a few photo shots of the situation first, in order to give you some appropriate advises.

most of the time you'll need a complete sand down & stripping but depending on how bad it was...

If touching up dont work, strip it and start over :wink:

I've had good results using an airbrush to repair areas painted with Tamiya TS-Series lacquer. Just mask off the areas you don't want to paint and avoid painting right up to the mask. In other words, leave a soft edge. New lacquer blends in nicely with the previous coat, and the boundary between old and new will be invisible after polishing.

This works best with an airbrush because it's easier to control. If you've sanded or buffed through the primer all the way to the plastic, it's best to re-prime and gently re-sand the area with 1500 grit paper. (Otherwise the plastic might show through the new paint.) Always scrub with soapy water and rinse well before painting.

But enamel and acrylics won't blend like that. With those paints, you need to either strip and repaint, or mask at the panel lines and scuff before repainting.

Ddms

I don't think it is too bad. I will try to touch it up because I don't want to disturb the filler underneath. If that doesn't work then I will strip it down.

I found that the primer and paint sort of filled in the grill which is located just forward of the front windshield. Anything I can do to prevent this? I had to take a knife and scrape it out to look normal.

Some pics would really help us draw more helpful opinions. If its down to the primer and a small area i would paint it down to the plastic, thats a tough call. You can prime that small area and then paint it. If using spray paints, if it was my model i would strip it.