For preparing to send to paint shop after welding on flares.

Which do you prefer?
bare metal > bondo > self etching primer
OR
bare metal > self etching primer > bondo

I will strip the car to bare metal as I go along...but I do not want to leave the metal exposed, and I dont move quick, so it will get a light primer so I dont hide anything...but enough to keep the panel from getting surface rust.

rich

I have been bare metalling my car for the last few months. As I do each panel I have been going over the bare metal with a wipe down with acetone to get rid of the stripper residue, then a hard sand followed by light sand and immediately followed by an etch primer out of a rattle can.
Then I expect any bog needed would go over that.
Richard

The only area I feel comfortable with commenting on is bodywork, but I would still trust the opinions of people like Mark, Scotty or Joe O over mine. However, I was always taught to lay down a good etch or contemporary sealer coat first. Then filler. Then paint. The filler, even the best brands, will absorb some moisture, which you do not want to come in contact with metal. You would want some sort of barrier between the filler and metal, IMHO.

Well, I just went over this this am. I have been using SEM Self Etching Primer over Bare Steel. Also did some filling over bare steel. I called SEM today to find out if I could fill over the self etching primer and they said NO. Fill Before. And, if I have to sand off the self etch if I need to do more filling.

I decided after researching to do just that, and seal with Glasurit 285-60 Primer Filler, which BASF states can be used over the self etching primer.

So,

Bare Steel,
Filler,
Self Etching Primer
285 Primer Filler
22 System Color

I know there are many ways to do things, but this stuff is so..... expensive, it is best to check compatability with the manufacturer.

John B.

do NOT etch then body filler. You need to seal the etch layer first with a coat of primer. Also do not etch and put epoxy over the etching primer. It's one or the other.

Cheap jobs I bondo right on the bare metal, nicer jobs: Etch, seal, bondo, seal etc.

Thanks Scotty, That confirms what SEM told me. I wasn't sure if all manufacturers had the same characteristics.

Rather than sand off the etch, I will prime over with the 285-60 and fill over that.

Have you used rattle can primers and sealers before or would only use two part mixed paints?
The cans I would use are from the paint store, so not rustoleum

Scotty......
Can I use rattle can ppg etch primer that I let sit for a while?

Then, when I am ready, seal everything and start bodywork with bondo?

Never used the rattle can etch before, but you should be o.k. To be on the safe side, I'd go over it with a grey sctotchbrite before sealing it just to get soem scratch for additional adhesion

On my first Porsche bodywork/paint job.

Click to view attachment

I used Rage Extreme filler on bare metal. Then covered the filler with SEM self etching primer. I took me probably took 6 months. It was done in Montana where its dry.
Didn't have shrinkage issues.

It was not stripped. I only sanded off the panels that needed a little paint and door ding repairs. No restoration. Just sanded down.

It went to the painter un-primered. It was primered and painted with Deltron 2000 system.

Bad news is that is will be restored after I finish the 914 I'm working on now. It will need to be stripped to bare metal. 4 layers of paint.