Primer/paint Newb Question

PPG makes a good product they have a etching primer in a can that work's well and a undercoating also if not 3m is the way to go. Eastwood has some stuff that work's pretty good I think it's a three stage process. Make sure if you take it down to bare metal you get primer on it just letting it sit overnight could result in surface rust. Good luck

@Davedacarpainter
For all things paint.

Beef97 said:

I actually have done lots of research on this topic but haven't found my exact situation in my searches. I'm resto-modding my 67 and the previous person had undercoated right over rust and grease. I'm taking it down (just the frame, wheel wells, engine bay etc....no body panels) to bare metal and want to prime it and then apply some sort of lizard skin (or something similar) product over the primer. My problem is that I am renting this house and cannot turn it into a paint shop. I don't own a compressor or any real knowledge of painting vehicles. I'll be needing to do this all from spray cans. I've been told to use a self etch primer over the clean metal (after prepping) and then pretty much confused after that. Do I need to coat it with something else first (paint or sealer) and THEN the undercoating product? Do I scrape the etch primer off and start with something else? I've just begun to strip the car so I'm in the initial stages. I'll have to do this in sections due to the massive buildup of grease, undercoating and rust. ANY advice y'all have for me would be beyond appreciated!! Thanks so much for your time and knowledge!!!

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Ok, so no compressor.

I understand the dirt and grease! My red car was packed with red oklahoma dirt. I laid down on my back for an entire day underneath it just washing all the dirt and grease out.

What I did with my red car is to use POR15 over the bare metal. It calls itself a rust encapsulator. It just seals itself up completely, not allowing any more moisture onto the metal. I coated the entire undercarriage with it, just as a precaution.

If you have any rust to deal with, first off, you have to determine how bad it is. (has it rotted through the panel?) if it hasn't, it needs to be neutralized with something like eastwoods products. You'll have to sand off all the scaling first. You may need to retreat it if the rust hasn't been completely neutralized from the first treatment. If it has rotted through, you should at least cut it out and weld in some new patch panels.

Can you take the vehicle to be sandblasted? That would completely remove the rust. It's not very expensive to have this done either.

Try not to just paint over the rust with the POR 15. It says you can do that though. I myself wouldn't.

I applied the POR15 over my entire undercarriage and even on the floor inside the cabin. I used a small paint roller and some cheap hf paint brushes for this. The POR 15 levels it self out real nicely, no brush streaks or anything.

After letting that dry for a couple days, i scuffed the POR 15 with red scotchbrites and sprayed 3M's undercoating over the entire undercarriage. I sprayed two coats. I just used the rattle cans that 3M offers. I think i used right at 6 cans of the undercoating.

The undercoating will also help with being a heat and sound barrier.

Do both things though, it'll last far longer than just one of them by itself.

Be sure to use a drop cloth when applying both of these products. Make sure you clean up the splatters from the POR 15, once it dries, it gets permanent. Even on your skin.

Here's some pictures after i coated the undercarriage and one of the interior. You may see where i had to replace the rear floor pan areas and some of the other patch work i did because of rot, plus a homegrown mini-tubbing.

BTW, Lizard Skin is a great product. I think they want you to use an undercoating paint gun to apply it though.

Beef97 said:

WOW Dave thanks so much for your help!! I will do some research on those products and let you know if I have any more questions! Super helpful! Would you say the por15 is better than taking it down to bare metal and using a self etch primer followed by a high build primer? I did a small section like that already under the front fender and it came out ok. Any info would be awesome! Thanks again for taking the time to respond everyone!!

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It depends on what area you're working on. If it's in a higher visibility area that you want to be real slick (like the engine bay), then I would smooth the damage out with the primer and paint it the body color.

Really corroded areas that you treat with the converter might need a little filler as well to help smooth it before you primer.

You don't need to remove the existing paint before POR 15. The area will need to be cleaned and sanded like any other area you would paint though.

For any bare metal areas that you intend to do the primer and paint to, always etch primer it. There is an epoxy primer that you can use as an alternative to etching and primering. It can be sprayed direct to metal (DTM). The epoxy doesn't play well with the acid in etch primer, so don't spray with etch before using it.

Etching primer is a great product. I've always used dupont brand, that sprays through a cup gun with air compressor. You always want to use a wipe on prep solvent before paint/ sanding or whatever. If you don't use it the grease and dust get dug into metal. After spraying etching primer, your supposed to spray grey or rust color primer over it. I have sprayed right over etching primer with color then clear, and worked for me. Again keep in mind spray cans never stick as well or give the gloss and depth that a spray gun will. But you got to do what you gotta do.


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