Primed Project..What to do?

[Jcslocum]

Hello All!

My daughter and I picked up a project this past summer and will be building the car for her as a DD over the winter. It's a '76 that has had Carrera flares welded on, soda blasted (Exterior only), cleaned and primed in some fashion. The PO did not know the exact primer so I'm not gonna try to guess.

What is the best method to remove this primer (unknown product) to bare metal and not damage or remove the zinc coating on the metal and then epoxy prime it??

We want to do it right and get the best anti-rust/corrosion possible for this car.

[quattrorunner]

Can't you just epoxy prime over top?

[962porsche]

because you have noidea of what primer is on the car or even if the primer that's on there is a e-primer (epoxy or etch)
it would be smart to sand a area to see how it sticks to the car and if any e-primer is under it .

the 1st thing you should do is take a rag soaked with lacquer thinner and lay it on a small area of the car . this will tell you if it's a reversible primer of not . if the primer softens back up you should remove all of it as it's a reversible primer and the top coats will not wantto stick well to it .
if it's not a reversible primer and there is a e-primer under it then there would be no need to try and removing it . as that is the type of primer you would want on the car .

as for the zinc coating there is no way to save it ! once you blast a car it comes right off so if the car was soda blasted it's all gone any way . the cars that have a zinc coating the thickness is about .8 of a mill thick so there is not much there .
many people think they can save the coating in some way and no that is not true .

if you need to strip the primer off the car you get your self a DA sander and have at it with 80 grit at 1st then once 99 % of the primer is off you change to a 180 grit paper and finish stripping with that . from there you blow off the car wipe it down with RM's 901 or a like then one coat only of a e-primer . let the e-primer flash off for 30 to 45 minutes and spray 2 to 4 coats of a filler primer .

as for putting a e-primer over what is there that is point less !
1st how well is the primers sticking under the e-primer your looking to spray?
then spray a e-primer over a filler primer is pointless as it's not doing any thing .


if you find the primer that is on the car is good then there is nothing to do but to just keep going and prep the car for it's top coats .

[Jcslocum]

962, Thanks for the info and I will sand it all off.

I was taught the all body work (filler) goes on TOP of the e-primer. Then the filler primer. You OK with this??

I always appreciate your body work posts. I know you are close-ish to my location int NY and I also wish your shop was still open....

[962porsche]

it can be done in two ways .
you can spray a coat of a E-primer down 1st then do the plastic work over the top or you can do the plastic work and then E-prime over it .
that depends on many things and the way your doing the job .
if your sending a car out for blasting and it's coming back in bare steel and you are a DIY in your own garage then it makes sense to get some coverage on the bare steel ASAP .
then some fillers don't like to stick to well to bare steel so again using it over a E-primer is the best way to go .
how ever it's ok to also get the back from the blaster and just do your body work on the bare steel then E-prime over it . that's if your not going to take a long time to get the work done .

you may find the primer that is on the car is totally fine so removing it could do nothing more than cost you a crap load of money and time for no good reason . this is why I said to check it 1st sand a little area to see how it's sticking to the metal and to also check to make sure it's not some cheap lacquer primer on the car . that's what the rag wet with thinner is about .
you will be spending about 200 dollars for the e-prime and another 200 for the filler primer plus the sand paper and masking tape . in total about 500 to 600 dollars just to remove and replace the primer they have on the car now . if the material on the car now is good your just pissing the money and time away .

[Bob Kontak]

Please forgive this mini hijack.....

On my 911, back when you could still buy 21 Line Glasurit, the jobber suggested I paint the bare panel first with a Glasurit product that was light green and really gummy. Well, it was not meant to be wet sanded. I then put a two part epoxy over that.

Was the green paint like an etching primer?

I get confused when I see the term e-primer. 962, I know you said etching/epoxy above, but these appear (based on my limited experience) to be two different things.

Also, on the 944 I painted two years ago I used Sikkens Washprimer 1K CF then used a two part epoxy primer. The washprimer was green but I was instructed to just cover, not really coat. On the 911, perhaps I used too much of the green stuff and that is why it came across as gummy. I only painted the rear bumper and one naked fender with the green stuff, so if I screwed up, at least it's isolated. Paint's fine after 10 years.

[962porsche]

yes epoxy and etch primer are two different types of primers but are used quite often in the same ways .

with E-primers all you want is one or two at most in the numbers of coats .
some can be mixed as a filler primer but it's rare .
like I have said so many times MORE IS NOT BETTER !
and that goes for any product you using right from bare to top coat .

the green primer your talking about is most likely there EP primer line epoxy .
the prime will take a long time depending on the mix to cure . there are 3 different ways to mix it by changing the activator .
you picked the wrong mix for your use i'm thinking or you just had to many mills of it . like I always say more is not better !
even things like spraying full wet coats when they say medium coats could screw you up big time .

you always want to pick a two or more part primer .

the only place you want or need a E-primer is over bare metals they do nothing over a painted substraight . you for the most part don't have to use the two etch and epoxy together .
some E-primer have what is called a induction time were you have to let the product side .
often it's about 20 minutes to a half hour before you do your spraying .
some E-primers you can not just go over with a top coat you would have to spray a filler type primer or sealer down 1st .

what we would do most of the time is .
as soon as the car came out of the blast area we would DA the bare body down with 180 grit .
then the car goes over to paint for them to wipe the car down with a prep wipe made for wiping down bare metal . it's not a wash just a wipe down product !
there is no need to metal wash a cars body if it has had no time to flash rust .
the car would get masked were need be and put in the booth for a coat 9one coat)of a chromated etch primer .
from there it's back to the body shop for the needed repairs .
at every step the guys always wear gloves nothing is ever put on the car when it's in bare metal . things like the da paper or any thing can not be placed on the cars when in bare metal the reason is any thing at this point can totally screw up a paint job .

we also only media blasted what needed to be done then so if were were not working the bolt on panel at the same time as the main body we left the other panels alone until we were set to go with them .
by doing this you don't have a bay full of parts sitting there flash rusting in bare metal waiting for you to start working on them .

[Bob Kontak]

Thank you.

You know, I can't remember if I used and activator with the green Glasurit primer. But I am certain that I put it on too thick. :-) It came in a brown can I think(for what it's worth). It's been 16 years.

[Jcslocum]

Thanks for the input everyone. Will test today now that it has warmed up a bit here in NY.

[962porsche]

today and tomorrow are going to be nice warm days out !
in the 60's they say for us on sunday .
that's the kind of winter weather I want to live in !

[gsxrken]

Jon, where in Hudson Valley are you located? I'm in Yorktown and would be interested in checking out your project sometime. I've never seen these cars down to the tub in person.
Ken