Rust mitigation/prevention

[E30andy]

Hey Guys!

Got my subframe out of my new to me 88ix to refresh bushings and all the other stuff that gets done when the subframe is out. It WAS a rust free car from Idaho that has new paint and is cosmetically quite nice, but after one winter in VT I am starting to see mild rust in all the usual spots at the rear of the car. My thought was to do some rust prevention while the subframe is out and I have access to lots of nooks and crannies that I usually cant get to.

Any thoughts about pros and cons of applying a rust inhibitor/protector? I am looking at POR-15 but am open to any suggestions you guys may have. I oil undercoat but doesnt seem to do much but slow down the inevitable.

Thanks!

[Slybeanx]

I would avoid any of the underbody "spray coatings".
I personally wire wheel, rust inhibitor, por15.

*although I have heard POR15 requires rust to actually bond to the metal I have yet to see it "fail" on my cars.

[rzerob]

POR15 will not stop the rust from spreading it will slow it down but not stop it. The only way to stop it is to cut it out and weld it. I have went the POR15 route before about 10 years ago and the metal basically disintegrated. It just got thinner and thinner until it was paper thin. As long as there is no rust underneath you should be fine with the undercoating. I prefer rust bullet over POR15 and if it is just surface rust try corroseal. I have painted frame rails on trucks and the like for years and it works great. Just know off the big stuff and paint it on. Stay safe.

[AWDBOB]

One of the bigger helpers I have messed with over the years is a high quality wax (cosmoline) coating. I personally use RP-342 over the POR or whatever product is used there. It helps, SO much.

Also, there are a few products that work better than POR 15. One thing I've seen on several cars is a lack of prep work for POR. Follow all of the prep instructions, neutralize the rust, and you will have much better results. Many folks just think they can paint it on and it'll magically fix the problem.

[E30andy]

Some pics of the rust

[AWDBOB]

That doesn’t look like it just started, but rather that its re exposing itself, esp battery tray and license plate lights.

[E30andy]

That doesn’t look like it just started, but rather that its re exposing itself, esp battery tray and license plate lights.

Something that was in the back of my mind as well.....car was recently repainted by the previous owner so who knows. Rest of the underside looks quite good so hopefully this is the extent of it.

[E30andy]

Couple more pics....
Last pic is my rusty black parts car parked next to the new to me ix.

[AWDBOB]

My brother has been cutting out/replacing all of the rust on his iX for the last few years. He found this stuff to be much better than POR:

https://nomorerust.com/store/rust-stop-paints/8-mastercoat-pemanent-rust-sealer.html

[E30andy]

My brother has been cutting out/replacing all of the rust on his iX for the last few years. He found this stuff to be much better than POR:

https://nomorerust.com/store/rust-st...st-sealer.html

I will give it a try thanks!!

[rzerob]

You need a welder. Either the piece of equipment or the title given to a qualified person. Anything else and it is a band aide at best and not a repair. If you plan to keep the car, fix it. Save the money you planned on buying the temporary repair and find someone to do it right for you.