Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Fact or fiction?

Does rust convertor work?-Kevin

I tried one a few years ago and it was less than effective. I guess if it get’s to the rust when it’s just surface rust…it may work. I was not impressed even though the theory behind it is sound.

I too have tried it and not been impressed.

All of the rust “converters” I have ever tried were almost useless.
The product that does work and I would stand behind is POR-15. I’ve been using that for 20 years and still have cars that I did back then that look the same as they did when it was first done. I also did some experimentation to gauge the effectiveness on various types of repairs. Rotted out cab corners, panel surface rust, scaly frames etc. It does everything they claim and then some. I’ve told this story before but I used to get strange looks when people would ask about the recently repaired frame laying outside in the tall grass- I’m prepping for paint! POR-15 actually works best if there is surface rust giving it something to grab onto versus smooth metal…

I guess one requirement is to have 100% access to all rusted areas for POR-15 to work. Rust can often hide in very hard-to-reach areas…

Depends on your motivation. I’ve used it to completely arrest the condition and stop it from doing further damage but I’ve also used it to simply slow it down enough to make it last the rest of it’s useful life (to me).

Here’s a rust deterrent that we used for many years and on many cars (until we moved out of the snow)…spraying the under-carriage, door interiors and fenders with motor oil. Either with a new car or one that was used, we’d take our car(s) to a fellow that had had a pit dug in his yard with stairs which you would drive over and park. He’d heat up new motor oil (he said used stinks) and add a chunk of wax, put it in the can of a paint compressor, go into the pit and spray away. He’d also do inside the doors (he’d remove a plug or two if the door had one or drill a small hole if not (then put in a new plug)), the fender wells, inside the trunk and under the hood (if necessary)…as little or as much as you wanted. On a 4Runner I had him go from the door handles down on the exterior and then not wash it until spring. It wasn’t too hard to remove (hot, soapy water), but that really shined nicely afterwards. He’d recommend finding a dirt road to go on too to get the dust to blend in with the oil to create a protective barrier. It worked great. You had to be environmentally careful as it would leak out the water vents in the bottom of the doors for a day or so, but none of the cars we had ever had rust develop with that process.

I’ve used Por 15 and it does provide a very good coating. Like a ceramic coating over the rust. I’m not sure if it stopped it or not but its such a durable coating, often it doesn’t matter. One thing though is you have to do a mist primer coat over it before it dries or paint will not stick to it, and don’t get it on your hands.

I have used rust converter, and where I’ve used it, rust has not returned.

Having said that, the instructions on the rust converter say to sand off the rust before you apply it as a primer coat, so it probably isn’t any better or worse than any other primer if you follow the directions.

Thanks a lot and what is POR 15 and were may it be obtained,Thanks Jimster,kinda like what Dagosa recommends-Kevin

Second the POR15. I’ve used it and it really does work as advertised, and is tough as nails. In fact, when you use it, you use a brush you’ll throw away afterward, and you’ll place a doubled up layer of plastic wrap between the lid and can, or you’re not going to get it open again unless you cut it open.

Ask me how I know this.

You can also spray Por 15 with a little air brush type sprayer. I think I used lacquer solvent to clean it. You pretty much have to order it on line. I’ve never seen it in stores. There are several colors now I believe. If I remember right there is a pint kit with a pre cleaner in it that’s really enough for most small jobs. You can also use it with fiberglass cloth to add extra strength to it. Saturate it and a couple coats over it to bridge holes etc. Its not cheap.

Thank you Bing-Kevin

@Bing … re the POR 15. My 70’s Ford truck has a rain gutter that goes around the roof perimeter, around the cab, and it is rusting along the inside seam in a couple spots. I’m worried it will rust through and allow rain water to drip into the cab eventually. I’d like to seal off those rust spots before it rusts through. Is that a good application for POR 15?

It’d be worth a try but then think I’d go over it with the fiberglass filler with the fibers in it to smooth it out and add some protection. Once it hardens though not much will stick to it without the fog coat of primer while its still tacky.

A body shop guy said he could cut out the rust spots back to good metal, then weld in a short length of welding wire, grind it out smooth, then repaint that area. Seems like it would work, but also seems like a lot of work. So if I could fiberglass some re-enforcement fibers into the area, then overcoat w/t the POR, that seems like a more simple solution. I hear you about the need for the primer while the POR remains tacky.

Use the Por 15 first over the rust, then the filler. Otherwise no point in using the Por. Or you can grind it clean and use a two part epoxy primer that works pretty good and then the filler. Or you can weld it but I’d still want to use the epoxy primer or Por over the weld area.

Good info, thanks @Bing .

I used the POR-15 Starter Kit available from Eastwood on my Blazer’s door when it started rusting on the bottom seam. I was satisfied with the results.

Good luck,

Ed B.

I have used iothers, several times over. Guess that tells you how effective they are. It’s suppose to be usable as a primer, so if you want it to last, paint over it. Even that after a few years, it still degraded and needed more attention. One place, around heavy duty parts like a hitch, it is more convenient then sanding and it looks better for a while. Just remember it’s better then nothing or just paint alone, but you will eventually have to back. WTH, just paint grease in it and try to avoid bumping into it. POR15, have to give it a try with all the glowing reports ! If it’s that good, why don’t car makers use it ? Probably because it does work too good.