Doc brown

There are plenty of rust inhibitors and convertors on the market. They are all basically the same. The active ingredient is Phosphoric acid that converts the rust to ferric phosphate, which is black. And of course marketing departments love that because then they tell the unsuspecting that their product "converts rust to black primer". Navel Jelly is the "original" rust convertor, is cheap, and works just as good as the other products, if you're planning to use that sort of thing. Interestingly, the MMSD sheets for Eastwood Rust Converter are dead links.

"Works good" in this context is a relative term. As CrazyCarKid stated, "once it's there, it's virtually impossible to stop". That's because even if you can grind it all off, its in the pore of the metal. It will come back. Not might come back. It will. Maybe not for a while depending on prep work and process used. Because of this, most body shops generally won't "fix" older rusty cars if they can replace a body panel. Its less labor intensive and will last a lot longer than a rust "repair". Most important, they won't have a customer back in 18 months later for a "free" redo of the work.

If it becomes truly necessary for a shop (or more likely someone restoring something very old) to keep a panel that has surface rust, they will sand blast it, maybe use navel jelly to get anything that's left, hit it with muriatic acid (to get the rust in the pores), which then needs to be thoroughly and properly neutralized, and then primed.

One product that interests me is POR15. I've read some pretty good things about it. It does use Phosphoric acid like the others, but what I find intriguing is that they have and overall process that's a lot more than just "converting rust". And for something like the rusty doors of the HHR, and my Trailblazer, this might do nicely to slow things down until I decide to replace the vehicles.

American & Proud

Lucky,
I wasnt responding to your post when I was typing mine out, more from another thread that they said it without any experience.

Are they just Glueing on the HHR door skins? (I havent looked at mine very closely only as I dry them off, knock on wood so far no rust blisters, Yet.)They used to be glued (seam sealer) and Spot Welded on. You had to break or drill out the spot welds.

Even just glueing them, and bending back and opening the flange lip would weaken the tight folded edge and more than likely crack the exterior Paint on that folded point, IMO.

The metal has gotten so Thin these days.

As you said, seeing some of the poor repairs that get done having been in the industry first hand would Shock most outsiders at times.

Some bosses just plain Sucked and refused to let you do it Right the first time.

Hopefully they got all of it out for yours, but as we know, Rust is like cancer once it sets in, it's only a matter of time ...

bk94si

I've used POR-15. It works really well but I don't know how you would get it inside the door.

Doc brown

Without pulling the skin apart, you really couldn't. My Trailblazer is all surface rust on the bottoms of 3 doors now. All I'd like to do is slow it down for a few years. POR-15 might work, it might not. But grinding, treating, and painting once a year isn't working either.

bk94si

It will stop if for sure on the outside, reacts with the rust and forms a nice hard gloss black surface. It would definitely beat painting every year.

urbexHHR

I've heard of POR15, no idea if it's good. The HHR doesn't concern me too much about rust. I did the best thing I can think of to help slow the process, quit driving it in winter! Might as well drive the Lumina since it's already rusty, that way once I start driving the HHR in the winter it'll last longer! Now the Lumina....still pretty good, but I've got a few panels I think I might replace this summer. No point in just sanding and filling the holes, either I got to replace the panel or forget it. Luckily it shouldn't be too hard, it's the rear quarter panel on each side where the bumper meets. Might have to look into that Por-15 though...

Lucky

American & Proud

there not spot welded just sealed at the lip. so far it seems to be holding up but it has just been a year so we will see. I was shocked the they could unfold the lip and get it back into shape and make it look ok. if i look at it close you can tell some kind of work was done but Im hopeful that it will slow the rust down. I plan on keeping this car a long time but I hate rust because it never stops. I would rather have dings and dent then rust.

Doc brown

Not a very good option IMHO. Not driving a car is the worst thing you can do to it in my experience. I bought it to drive, not mothball it in a closet.

urbexHHR

Yeah, but when you've got 3, you've got to decide which ones you want to drive when. I'm not storing the HHR to keep it forever. I will drive it in the winter, but right now I've got the Lumina, and I'd like to drive that too.

Gas Man

And it's no wonder why I had mine rust proofed.