Went under the car to try and remove some rust belt souvenirs

[Delta_V]

I bought this car this month and I already knew from the start that I wanted to clean it up and remove/neutralize rust to the best of my ability in a practical sense. I live in Nevada where its dry and we hardly ever salt the roads (if at all), so I know whatever work I do should stay as I leave it.

The car isnt terrible corrosion wise by any means, the underbody panels do a pretty good job of keeping corrosion down-but the rear saw a reasonable amount of surface rust.

To combat this I purchased loctite naval jelly and several brass wire brushes to get to work. I started by removing 3/4 of the undercarriage shields and exposing the engine area and the transmission. Most of the aluminum components had a good coat of dry salt and some discoloration from corrosion, so I just used brushes and warm water/vinegar followed by a warm water rinse to try and remove it the best I could. I also found the some of the power steering hard lines were rusted and i wanted to remove as much scale as I could to try and stop the rust from continuing to corrode.

I was able to brush a reasonable amount away, and I will be painting with rust converter/neutralizer tomorrow or the following day.

The real work and where the photos show the most effort is in the rear. I used the brushes (attached to a drill) to blast off as much surface rust as I could. I didnt care if it was a painted or non painted surface, as I will be recoating the painted parts anyways , and possibly treating the aluminum with something.

I noticed that the driveshaft had the most corrosion of any of the surfaces, but it was blocked by a heat shield. To remove the shield I needed to remove the exhaust-where I found some corroded studs/nuts. Luckily, only one broke off and it happened to be a clean break...it was also the only one that wasnt a stud pressed into the exhaust, so im easily able to replace it!

After removing that, I found the torx bolts to be quite difficult, so I decided to wait until tomorrow whilst I tackled the diff and other misc rusty parts.

I blasted them with the drill, then rinsed, then applied loctite naval jelly to the surfaces. I let it work for about 5 minutes (nervous that it might eat away at the metal too much) and then rinsed and inspected.

It worked fairly well, but wasnt quite where I wanted it. I applied another coat, let it sit 10 minutes, and saw great results. This chemical definitely works as advertised. I will be applying another coat most likely and then finishing with the wire brush, an alcohol cleanse, and then rust converter. After that, Il be coating it with high temp or similar rust preventative coating in black.

I also hit the left rear rotor and cleaned the hub to my standards. I didnt bother wasting too much time with the innermost part where the rotor sits over, but I did descale with the wire brush and wipe clean with alcohol. I focused on the inner portion which was rusting the worst, and on the mating surface that touches the wheel. The results were excellent and I am pretty happy with how it looks (the new drilled and slotted rotor does make up for 90% of that)

Tomorrow il continue with the cleanse and try and remove/convert all rust spots. I want the car to

1. Stop rusting in existing small spots, preventing further binding/cracking of paint/broken bolts

2. Look as factory new as possible given that I have limited tools and a garage with commercially available treatments.

Ive had a lot of experience removing and reconditioning rusty vehicles/parts and I am super excited that this project is 100% manageable. I have seen trucks rusted in half from neglect and continuous exposure to salt, and Im just happy I can save this vehicle from any more punishment!

[desertman123]

Wow everything looks way better!

[dtla1]

Before and after looks great so far!! It looks like you might be spending some time on the rear suspension cleaning, might be a good time to replace some pieces for upgrades, if you feel inclined. My personal recommendation would be replacement of the Subframe bushings to a 2-piece poly (whiteline, powerflex, etc) and the upper control arm upgrade kit (I felt this made the biggest in stabilizing the rear over bumps).

This thing is going to look brand new when you're done with it.

[NorthernDancer]

Wow, that's a ton of rust on a Nevada (?) car. Anyways, you really do know what you're doing and keep up the good work. Scotch Brite pads may also be useful, also WD 40 and Fluid Film. Also remove front and rear bumpers. Many of us in snow/salt country store our cars for 4-5 months ever year. Hence my car (2008) has the mileage (62K miles) of a 2011 or 2012.

[chris_flies]

My 200k-mile car from Maryland/Northern Virginia isn't even close to that bad underneath.

Nice work, it looks much better

[Delta_V]

I will probably wait on the bushings another few months, just purchased a BMW performance exhaust from a member here that I will be throwing on when it arrives..til then il just be finishing up with rust removal and making a list of all the fasteners I want to replace. Essentially anything under the car that was exposed needs to be at a minimum loosened and retorqued after cleaning or applying anti seize. As many of you know the rust travels up the threads even if the head of the bolt looks good, so I just want to squash the items LIKE subframe bushing bolts, shocks mount bolts, alignment bolts etc that will important for maintenance later.

Today I brushed for another few hours to get as much as I could with the tools available. For the area's I could see but couldn't reach with a brush I used a cleaner/degreaser and then brake cleaner and alcohol to make it as clean of a surface as possible for the rust converter.

I decided to use Rust-Oleum rust reformer as it has good reviews and I've used it in the past with success. It's also affordable and available at most hardware stores.

After I cleaned up what was leftover from yesterday I removed the heat shield and exposed the driveshaft. Not super happy with the u joint condition, but I was able to brush about 90% or more of the rust away from outside and inside of the joint. I was also able to clean off the driveshaft to a very acceptable finish.

After that, I started prepping by using high pressure air to blow out anywhere and everywhere that would be painted. Then I rinsed with warm water in a spray bottle to get the remainder off. Finally I used brake cleaner and mineral spirits to completely remove all contaminants from the surface .

I also removed the right rear caliper and replaced the rotor l. When compressing the brake pads in the caliper a small amount of brake fluid seeped from the piston-im hoping it was slightly over extended from being off of the rotor overnight and so a bit seeped past and then surged out when compressed. I reassmbled it and il check it tomorrow and hope I find no brake fluid...!


These are some photos from today. The rust reformer turns rust to a matte black finish, and has a black primerish paint within it. I coated everything I wanted to tonight and il let it cure for 24 hours to ensure the chemical processes are complete.

Tomorrow il lay a top coat of gloss black engine enamel (which wasn't really necessary, but here's to hoping it's a hard drying paint like I want it to be).

[Delta_V]

Originally Posted by chris_flies

My 200k-mile car from Maryland/Northern Virginia isn't even close to that bad underneath.

Nice work, it looks much better

Yea it's interesting- the rust is primarily in the rear lower portion of the vehicle. It really doesn't go too much into the rest of the car...but whatever they use in new York/Chicago, it's rough!

[Suprgnat]

Originally Posted by Delta_V

These are some photos from today.

Nice work.

[Delta_V]

Alright ..finally finished up! Started with 500 grit sandpaper on the rust reformer...cleaned it up with some warm water and a dust removal tack cloth...then proceeded with sandable primer. After the primer set I applied another coat, then let that dry before putting on the final gloss coat.

It came out really good. Some overspray, but nothing that i care about. I used a piece of cardboard to protect the undercarriage from overspray as I was painting, but you can't get it in ever spot!

Replaced the exhaust nuts and one bolt with stainless hardware coated in antisieze...much happier now!

[Gray_Panther]

Fantastic work! I only looked at the pics, but how did you go about taking the rust off?

Edit: Read it, good job with the sandpaper, but damn that must have taken a long time!

[Delta_V]

Originally Posted by Gray_Panther

Fantastic work! I only looked at the pics, but how did you go about taking the rust off?

Edit: Read it, good job with the sandpaper, but damn that must have taken a long time!

Took me three days of 8hours ish each from start to finish. Definitely time consuming, but I enjoyed it!


Used an Amazon wire brush kit that is made for drills. They wires were brass so they are soft enough that they don't take much material out but blast the rust. They also sell nylon brushes that act as different grits of sandpaper. I did it by hand for the paint prep but the rust definitely came off with the drill.

If you do this, buy a good mask, good eye pro and a cheap harbor freight wired drill to save your frustrations due to dead batteries. Definitely worth it.

Il update again in a year or so , or sooner if I see a problem with the finish. Because I don't drive it in inclement weather I doubt I'll see anything with how dry it is in the garage /Nevada.

[Dekdo]

Nice post, I need to do a bit this myself

[Ftpohyeah]

lol id pay you to do it

[Kristopher]

Oof I'm gonna have to tackle this problem myself on Monday, I'm from California and got a good deal on one from Chicago but came with the obvious "surface" rust problem on the underside of the car and looks very similar to your pictures 😭

[Delta_V]

Originally Posted by Kristopher

Oof I'm gonna have to tackle this problem myself on Monday, I'm from California and got a good deal on one from Chicago but came with the obvious "surface" rust problem on the underside of the car and looks very similar to your pictures 😭

Yep, Also from chicago. Definitely nothing structural/problematic for the actual functioning of the vehicle, but I just wanted to make it as clean as possible. BMW actually does a great job with their weather/corrosion protection...I was impressed.


I did all this work, and I dont drive the car as much as Id have hoped....Definitely fun lil bimmer but I might be letting her go sometime this year!

[Delta_V]

Originally Posted by Ftpohyeah

lol id pay you to do it

If I had a lift and a garage, I might be able to make a small business out of this in the midwest!

[jeremy121]

What a great post. So you can help if there will be any problems with rust) What can you say about rust converters such as MRO Chem Black Star Rust Converter for example or any others described here https://chemicalwiki.com/best-rust-converter/? Are they good enough?

[Lucky1]

Originally Posted by Ftpohyeah

lol id pay you to do it

Was thinking the exact same thing :

[Delta_V]

Originally Posted by jeremy121

What a great post. So you can help if there will be any problems with rust) What can you say about rust converters such as MRO Chem Black Star Rust Converter for example or any others described here https://chemicalwiki.com/best-rust-converter/? Are they good enough?

So personally, I have used rust converters on older metals and trailers, the key is to still remove all loose rust or scaling. You can't use any of these products by just painting them on. All of the work, done properly, should be brushed, descaled and sanded. You'll find with many applications that this process gets rid of about 90 percent of your corrosion.

This car isn't a great example of a truly rusty vehicle. There was no corrosion beyond light surface blemishes, and with a light standing a rust converter would do the job. The converters Penetrate and chemically change the rust which stops it from continuing. The problem with some people who have real rust issues is that they get lazy and try to paint the converter without first prepping. Any good systems will have a multi step process for the user to do which involves everything I talked about.

If you just paint converter without prep on a surface that has reasonable corrosion, it will adhere and convert to the outside but most likely leave the lower levels of metal and rust untouched. The finish will flake off with the rust eventually, and if exposed to more salt or moisture could continue to rust out of sight.

kbs coatings makes a great system that you can use!