primer prep for basecoat?

[projectPONY]

ok, I'm about to try something different. in the past I have always straightened a body panel as best as possible with a hammer and dolly. then apply a high build primer and block. then I'll do anymore bodywork directly on properly blocked primer, then prime again and final block for paint. I've never had a comeback.

this time, this panel is really straight just some minor waves here and there including some light dings. I DA'd the panel down to bare metal first. I did my body work and then applied a urethane primer. I was very generous with it too. I then blocked with some 220 grit on a long block. the panel is STRAIGHT.



what I did next makes me a little unsure of myself. since the panel showed to be very straight, I proceeded to spray another coat of guide coat and final block with some 600 grit. my question is this, should I have primed again after the 220 blocking? the panel showed flat and I didn't break through the primer anywhere on the panel and it was on pretty thick. I'm concerned that sandscratches will be visible after it's based and cleared.

TIA

[astroracer]

If the guide coat blocking didn't remove all of the 220 work you will have sand scratches looking back at you... Wipe the panel with some wax and grease remover (or simply wet it with water) and look for scratches. If there are any you should be able to see them. Go from there.
Mark

[danbob67]

I hope that you didn't put that urethane primer over the bare metal. a etch primer then urethane or a epoxy then urethane are the only good ways to go over bare metal. as far as the 600 grit over the 220 goes you might be Ok if you seal it but 220 is a bit tuff to 600 out and not have any worries with sand scratches.

[projectPONY]

I'm getting ready to seal as I type.

[projectPONY]

I hope that you didn't put that urethane primer over the bare metal. a etch primer then urethane or a epoxy then urethane are the only good ways to go over bare metal. as far as the 600 grit over the 220 goes you might be Ok if you seal it but 220 is a bit tuff to 600 out and not have any worries with sand scratches.

yes, I did use an etching primer first.

[projectPONY]

ok, I just finished applying the basecoat. I got a few sandscratches here and there. fortunately this customer is not picky. they are very minor and I'll just have to see what he says. this will be the last time I do it this way, I should have primed again.