I was searching around and found I can buy Sherwin Williams paints online from their site. http://www.sherwin-automotive.com

So what's the difference between their high build primers like RS3400 Polyester Primer and P48/P50 primers?

I'm a little confused on which one I should use.

The P48 and 50 primers are regular high build primers, if I remember right the 50 being alittle higher build then the 48. My shop used S-W paint now switched to PPG, used the p48 primer. Really liked the stuff, sanded nice filled good too, better then PPG's K36 primer.

Now the diff on the 48/50 and the poly primer is that the poly is a very high build primer. Condiser it a sparyable bondo. The only times Ive used the stuff is on large panels or on panels that are just beat to sh$t. In all reality there is no need for the spray poly. Block sand your car around 4 times and you can get it straight with 48/50. If you cant do that then you need better metal and filler work done first. You need to get the car as straight as possible before and after bondo.

The poly is cheaper but in my book not as good of a product. The PH48/50 primers are of a much higher quality. Plus most poly primers cant be applied over etch primer, where the PH48 can.

As said before I think the only place poly shines is on panels that need a lot of bondo work and spreading out the filler evenly would be hard. But otherwise its hard to beat a good urethane primer as PH48/50...Eric

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1970 chevelle
1970 chevelle SS455 not a typo its a BUICK BABY
1949 and 1972 chevy trucks
http://briefcase.yahoo.com/bc/sevt_chevelles

Thanks for the info, Looks like I'll go with the 48 or 50. Now just need to decide on which topcoat to use.

Thanks