Stayed up till 3am (waited for kids to be in bed) to spray for my first time ever. I sprayed a cab with 2 coats of rust seal and noticed some runs and dust in the finish this morning. I know rust seal is not a finish coat, but I want to eliminate the flaws before I spray a top.

1.How long should I wait before I sand out the imperfections?

2.Would 400 grit work well enough?

3.After sanding the rustseal smooth, do I have to reapply another coat of rust seal or can I just continue with the top coat.

Thanks

I'd give it a couple of days at least before sanding. 400 grit should be good but it may take alot of sanding. If while sanding, you penetrate down to the bare steel, then I would apply another coat of RustSeal. If not, just apply your topcoat.

Hope that helps.

Yep. I actually had to start using 320 grit, because like you said the 400 was taking too long.

I noticed as I am sanding the rust seal smooth, there are "freckles" here and there. The freckles are small shallow dimples in the paint, perhaps from my inexperience in spraying. You can see them because they are concave and they remain black while the sanded areas turn grey.

Does the fusion self etch primer, my next coat to lay down, act like a filler as well to hide these small imperfections or should I spray another coat of rustseal first?

Thanks

Fusion is not a fill primer, but it will fill some. Sounds like you may have just sprayed a little heavier to create those craters. Did you thin some before spraying?

Well not enough thinning I would say. Now that I have the Fusion SEP I am going to spray it and perhaps follow up with a filler where needed. I already gave the rust seal a light sanding.

That should work perfect for you.

Please let us know if you have any other questions.