paint guru input needed

[freezing14]

After 4 years of work and parts accumulation
Now paint
So lots of hammer work later then filler then primer then guide coat and repeat and repeat so after about 100 hours of sanding the car is strait and ready to actually have color on it

So now the car has a coat of primer on it and was sanded with 600 and its all nice and smooth

Here is the question

Do i put a last coat of primer and let it set for a few hours to have a rough surface for paint to adhere to or paint on the sanded primer

Which is better and why

Thanks

[Orval_F]

What do the instructions for the paint/primer system tell you?

I am used to painting aircraft with 2-prt epoxy primers and 2-part polyurethane (EXTREMELY toxic!) top coat. I have used PPG, Finch and Imron. They can all be compounded to appear like hand-rubbed lacquer, using 3M systems. Even runs and sags can be removed.

[freezing14]

The paint is ppg and instruction says
Apply paint on primer with 24hr if more then that sand then paint

So we can do both but which will be better or easier or more forgiving

[NorthernThrux]

Let the primer cure. That way you can double check for smoothness and any spots that need work. Then a light sanding and on goes the paint. If you have to sand that paint for any reason, having the cured primer underneath will help it from coming up as well.

Ravi

[NV Stig]

Is it possible to find the original paint that went on these cars? That 1 coat Glasureit (SP) stuff?

[mac73s]

I am very familiar with the PPG product line and process you have just undergone as I did on my 73-S. I would encourage the application of a sealer just prior to the color and clear (assume you are using a base/clear process?). In my experience, yes, the final primer coat should be wet-sanded with 600 (which as noted should be fully cured), and then sealed just prior to the color top coat and clear. Most I feel would agree that the sealer is good insurance.

[moito]

I am very familiar with the PPG product line and process you have just undergone as I did on my 73-S. I would encourage the application of a sealer just prior to the color and clear (assume you are using a base/clear process?). In my experience, yes, the final primer coat should be wet-sanded with 600 (which as noted should be fully cured), and then sealed just prior to the color top coat and clear. Most I feel would agree that the sealer is good insurance.

sealer is good

[Scotty B]

wet sand with 600, tape it up, wipe it down and shoot. No need at 600 grit for any sealer UNLESS you have spots that broke through to bare metal or high build primer. You'll see a color difference if there is.

[Scotty B]

Is it possible to find the original paint that went on these cars? That 1 coat Glasureit (SP) stuff?

Possible yes...but not needed. I have used Spies Hecker, Glasurit, and PPG exclusively and quite honestly find Glasurit to be overpriced and is NOT a guarantee match. I'm dealing with a 76 signature Ed right now that Glasurit won't release the formula for. I bought a pint of the color in Glasurit and it is NOwhere near close. I also regularly have people that insist on single stage paint, even a couple old Hot rod guys that insist on lacquer. It can all be had

[freezing14]

i forgot to mention sealer ,

as i am going to do as close as the factory did so , I am going single stage 2K , sadly the glassurit stuff is MIA
my last car , ( 914-6) I did base coat clear coat , but I have read here that some people have judged car lower for being too shinny ( BC/CC) so being influenced by the real porsche fanatic ( i am getting there too) , I opted for single stage , even without the shinny additive

the car is a bare shell , and will be painted all apart like the factory did,
I have masked the wurtz as it did not have any oversparay under, the inside of the cabin had color overspray

it will take me an other year before all the other parts are on it ( powder coat, plating etc )

thanks for the help guys