I'm restoring a 67 Chevelle and want to go over the entire body with a polyester primer
and then block sand.

I'm wondering what the best application would be over PPG DP90LF epoxy or similar?
I have been looking at Slicksand, G2, and Superbuild 4:1. Will consider others but
I don't want to skimp and buy something cheap and have issues down the road.

I was planning on scuffing the entire body with 80 grit, applying the epoxy and then
once thats flashed off apply the poly...I have not shot the poly before so helpful
comments will be appreciated. Looking to get either 2.5, 2.8, or 3.0 tipped primer gun

Thanks
Chuck

I would like to know why you need to go over the entire body this stuff. it doesn't sand that good with finer grit papers, you'll have to block with 80 grit to cut it down flat. then coat it with something else to get it smooth. personally I don't like the stuff. why not just use a good hi build primer if your body work is good the hi build should be ok. if you do use it, ask some questions before you spray it. I think you'll be lucky to get around the complete car before it starts to harden in the gun unless your real fast. what i'm saying is you can't screw around everything needs to be ready if it starts to thicken up get the gun cleaned quickly.
Jay D.

Just about every panel on the body is new. I dont want to build it in high build cause that stuff shrinks way more than the poly. Id probably do a better job with the spray poly than skim coating the car by hand.

I plan to initially block my guide coat with 80, then re guide coat and block with 180. In a perfect world mov on to the high build primer and block again with 320. Should be close at that point getting all the lines straight and panels flat

gpracer15 wrote:I plan to initially block my guide coat with 80, then re guide coat and block with 180. In a perfect world mov on to the high build primer and block again with 320. Should be close at that point getting all the lines straight and panels flat

That's exactly how to get a straight show car finish, and it's much easier then
coating the entire car with regular filler like the car shows on TV show.
You can do the same thing with 2k primer by putting on a lot and blocking
with 150 or 180, then recoating and going to 400 to 600.
The trick with doing it that way is to let the primer age several days
to shrink before blocking. then it will hold.

I use the G2 and it sands fairly decent especially since you are blocking with 80 grit.
Seeing all your panels are new I would say one gallon will be enough but I shoot the G2 through a 1.8 tip. If you go much larger obviously the poly will be used up quicker.

Badsix is right about polyester primers setting up quickly, usually 20 minutes or so work time but since they chemically hardener (like filler) you must be conscious of the clock. Have some Acetone handy, you will need it if you choose to reduce the poly primer and also to rinse your gun between cups.

I mix only one cup at a time and depending on your spraying speed plan to rinse the gun with Acetone before the poly sets up.

For a car with new panels I would suggest regular build 2k primer rather than poly primer.
Shrinkage is only an issue if you have excessive build and you should not.
I like to spray 2 coats black epoxy primer as my foundation. Then follow with 3 coats of regular build 2k (following tech sheets for flash and re-coat).
Block sanding with at least a 9" block and 80 grit until I start to see the black epoxy showing. Shoot 2 more coats of regular build, guide coat and block with 180 just until the guide coat is gone.
Build will be minimal this way and shrinkage won't be a problem.

The Tamco line of 2k primers sold here seem to have little or no shrinkage in my experience with them.

this right here^^^^ much easer and better
Jay D.

DITCH the poly! Do what 68 Coronet said,Thats what I do.