My understanding is that once the car is primed and block sanded to your satisfaction, a sealer needs to be applied. Using PPG products, I've taken the card down to bare metal, used the etching primer, followed by K36 which was block sanded. Now comes time for the sealer,color and clear. My question is, won't an uneven application of sealer negate all the block sanding you have done? Or is it a case where you can/do re-block the sealer? I didn't think so, but want more information. Thanks.

The sealer is a very thin coat, unless you use a cheap paint gun. The sealer has almost no orangepeel. You can seal, let it flash over the shoot the color and clear. Or you can wetsand the sealer after it cures for a smoother finish. I doubt you'll notice the difference unless you use a cheap gun or have the wrong settings. You just have more work. Personally, if the sealer goes on right without runs, dirt or sanding scratches and the panels straight, go ahead and shoot the color. If not, you still have time to correct it.

I agree with Allen.
If you still have doubts, talk to your PPG dealer. Tell them you want a non-sanding sealer. It goes on smooth and even if you spray it right and there will be no orange peel.

Most sealers help with the coverage of your topcoats,also helps with color holdout and promotes adhesion.If you do wet sand it,don't use anything finer than 400-500grit paper.If i'm not mistaken,you can use k-36 as a nonsanding sealer.Sealer should be sprayed over properly prepared surfaces sanded with paper on coarser than 320.

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Real cars have three pedals !!!

What PPG line are you using?

I understood the Global line is the best. I was going to go with that. My problem is finding a painter willing to just spray the sealer/color/clear. I don't have a good enough gun to shoot it myself, although if I don't find someone to do it in a reasonable timeframe, I just may buy a decent gun and do it myself. I know there are plenty of pitfalls, problems, and dangers from reading posts on this topic. At this point I'm waiting for a guy to come over and look over the body and give me an estimate.

As long as the primer is blocked right, you really shouldn't have any problems. Sealer goes on real thin. If the sealer show any imperfections, I'd layer 2-3 layers of sealer and let it cure. Wet sand the sealer with 400, then base/clear. If there's no imperfections, go ahead and base/clear after the sealer. It'll save you time. You should have the painter lay extra clearcoat so you can color sand the clear. By the way, what color are you painting the car?

It's going to be a very bright yellow with black stripes. I'd prefer something else, but my son really likes the yellow he saw on a 2001 Saturn. I'm trying to get him to look at a car thats been painted with Dupont Chromabase yellow, but he seems pretty set on what he has seen.

If you have a 2K primer on the complete panel or panels, you don't need a sealer at all. the 2k is insoluable, so the base coat or single stage is not going to soak in. Just sand the primer with 500 or 600, and paint.
But if you have a a few different subsrates or some questionable sanding etc, seal it.

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1965 Buick Gran Sport Convertible
1965 Buick Skylark H/T
1948 Chevy PU with 401 Buick

you can use 2k as wet on wet sealer. i think you use 1:1:1 ratio i think, correct me if im not right, ill check my p sheet later. but no you do not have to sand it unless you lay it down really bad.

Global D 825 sealer mixed 4/2/1/2 is a wet on wet sealer, and with a slightly different mix ratio it can be used as a primer surfacer. I use the Global line at work. I would recomend the D894 clear. BTW if you know of a DuPont yellow you like get the code then give it to your PPG supplier and he can cross it to a PPG formula.
Austin

Thanks for all your suggestions, and help. I will let you know how it turns out.

i was talking about the 839 2k primer. i use it. we just did my bro truck with it mixed as 5:1:1 and a filler primer and it worked really good.

I show the same mix ratio for the 839 4:2:1:2(if used as a wet on wet sealer). How do you like the 839, do you use it as a primer also? We use 825 for sealer and 822 for primer.
Austin

you dont need to seal it if your prep work was done correctly.