Talking Cars Tuesday - Let's Talk About Rust

Submitted by XM - Mt 1822 on May 3rd, 2023 at 5:55 AM

Mates,

Vehicle longevity is affected not just by the mechanics of things like engines and drive trains, but also by how the chassis holds up.  Many of us are old enough to remember when Detroit was churning out new cars that would start rusting 15 minutes after you left the showroom (n.b. slight hyperbole there).   And just like summer follows spring, so too does rust follow the salty roads of winters in our beloved Michigan.  Some vehicles/years were notoriously bad for rust, some just the opposite, pretty durable.  

Along those lines, today's questions are:

1.  What are the best vehicles to withstand rust - make/model/year, whatever, which ones are best?  Just as importantly, what is it about the manufacturer and/or their process or design that makes their steel better? 

2.  What are or were the worst for rust?

3.  If you have one, what is your best, "my old rusty car is/was so bad that...." story?

Have a great day.  Do not despair, actual spring weather will come.  Some time.  During our lives.  I promise.

XM

p.s.  Some here may get picky about the idea that it might not actually be Tuesday.  It's Tuesday somewhere,. or it was Tuesday all over and that's good enough.  Besides, Wednesday is very good friends with Tuesday and they hang out.  So, Tuesday. 

Wally Llama

May 3rd, 2023 at 6:48 AM ^

I'm not a corrosion expert, but I do work for a company that makes driveline parts. In my world, carbon steels are typically used due to their relatively low cost and high strength. People like their cars to go, so strength is a priority. Steps taken to prevent corrosion include:

  1. Paint. Powder coating is common, but water-based paints are also used. Either way, pre-treatment of the surface is vital to ensure adhesion. Peeling paint doesn't prevent corrosion very well. Impact hardness is critical, too - as soon as you get a stone chip in your paint, all bets are off. This is the most common method in driveline parts.
  2. Plating. More expensive than most painting due to the materials used, but better at keeping the final shape of the part.
  3. Use aluminum. Mich lighter and won't corrode like steel, but much weaker and much more expensive. Can also have issues when joining to other materials,  including galvanic corrosion.
  4. Use stainless steel. Carbon steel alloyed with chromium won't corrode but is expensive and difficult to join. This was DeLorean's body panel solution.
  5. Use plastic. Solves the corrosion problem, but much weaker than steel.
  6. Use carbon fiber. Crazy expensive, but super light and no corrosion worries. Can be difficult to join to other materials.
  7. Use magnesium. Even lighter than aluminum and more expensive yet. Also dangerous to machine as small magnesium chips are wonderful for use in fireworks. 😳

Someone who knows body panels better than me may have better insight as not too many folks care if their driveshafts are rusty, but if that fender shows rust, it's an issue.

P.S. - it was still Tuesday in Hawaii when you posted this, so all good. (I'm sure this validation is critical.... 😉)

mGrowOld

May 3rd, 2023 at 10:35 AM ^

1. Thank you for the well-wishes on the hip.  Agreed, virtually everyone I know who's either had one replaced or have a family member who had one replaced reported it went well and relieved their pain.  Except one person - my brother in law - who just had one done himself and is experiencing significant leg swelling and discomfort.  Dr said it occurs in about 1 out of 100 cases so I'm really hoping he took one for ther family team.

2. Very nice humble-brag.  Speaking here as a subject matter expert in the field (just ask Timmaaay) I'm impressed!

HighBeta

May 3rd, 2023 at 12:43 PM ^

Yes, it is, indeed, Wednesday here in the continental USA.

From familial experience: knees are miserable, hips and shoulders are easy. Good luck with the new body part!

By the way? Did you also know that the current coach of the University of Michigan's football team is (still) Jim Harbaugh?

😉

KO Stradivarius

May 3rd, 2023 at 10:00 AM ^

This is spot on. I do have experience with body panels. Things like doors and tailgates rust faster (steel or aluminum) when water gets trapped due to improper drainage and/or sealing, in addition to  exposure. Not much you can do if it’s designed poorly, you probably shouldn’t start drilling drainage holes yourself. This is why some vehicles tend to be chronic offenders.

Undercoating is great if done correctly. It coats the backside but if it plugs drainage then it’s detrimental.

Another reason is a paint chip, so touch those up ASAP.  Especially behind the wheels, bottoms of doors, rockers, front of hood and roof, etc. They become stone pecked. Once there’s an opening it will become pitted and rust will start there. Waxing the panel will help as well (use touch up paint first and let dry).

I’d also believe that the aluminum body Ford pickups will be good performing against rust.  But all it takes is one bad joint (they do isolate them) where steel touches aluminum due to a quality problem or bad design and galvanic corrosion will happen.  But overall you’re better off IMHO.

EDIT: Many vehicles nowadays have aluminum (or plastic) doors, hoods, fenders, liftgates, etc to save weight and reduce closing efforts.  Those are self-contained so they are easier to implement vs using aluminum in the rest of the body.

One thing to note is that corrosion testing takes so long it is hard for a car maker to do it before a vehicle goes into production. By then it’s hard to fix the problem. So engineers just have to follow good design principles and use experience from past models.

IOE86MBA01

May 3rd, 2023 at 6:48 AM ^

I drove a 1967 Chevy II in high school in the early 80's. My buddies loved pulling up the floor mat to spit on the road instead of needing a spittoon.

mooseman

May 3rd, 2023 at 7:09 AM ^

My dad was a Ziebart man. I just looked it up because I hadn't heard that name in a while. I didn't realize it was 1) still in business and 2) a Troy, MI based company

mooseman

May 3rd, 2023 at 7:16 AM ^

https://www.youtube.com/watch?v=ZCT3jm1A-5U

Then in a later scene after Puddy gets back with Elaine:

Jerry: Alright, alright. Alright, that's enough! Let's get back to my deal. That undercoating, that's just a rip-off, isn't it, David?
Puddy: Oh, we don't even know what it is.

dickdastardly

May 3rd, 2023 at 7:35 AM ^

TOP 10 MOST RUSTPROOF CARS

Protégez-Vous magazine, in collaboration with the Automobile Protection Association, last week published a list of the top 10 best and worst vehicles when it comes to preventing rust. Here they are:

Best

  1. Audi A3, A4, S4;
  2. Volkswagen Golf, GTI, Jetta, Beetle, Rabbit, Passat, Passat CC;
  3. Volvo S40, V50, V70, CX70, S60;
  4. BMW 3 Series;
  5. MINI Cooper, Countryman;
  6. Honda Civic, Accord, Fit, CR-V, Odyssey, as well as Acura CSX and TL;
  7. Toyota Camry, Corolla, FJ Cruiser, Highlander, Matrix, Prius, RAV4, 4Runner, Sienna, Solara, Venza, Yaris;
  8. Mercedes-Benz B-Class, C-Class;
  9. Hyundai Accent, Elantra, Entourage, Santa Fe, Sonata, Tuscon;
  10. Kia Forte, Magentis, Optima, Rondo, Sedona, Spectra, Sportage.


Worst

  1. Mazda3, Mazda5, Tribute, MPV;
  2. Jeep TJ, Wrangler;
  3. Ford Focus, Escape, Explorer;
  4. Saturn Relay, Vue;
  5. Buick RendezVous, Terraza;
  6. Suzuki Swift, XL7;
  7. Nissan Altima, Maxima, Sentra;
  8. GMC Terrain;
  9. Pontiac G5, Montana, Torrent, Wave;
  10. Chevrolet Cobalt, Equinox, Uplander, Aveo.


Source: protegez-vous.ca

St Joe Blues

May 3rd, 2023 at 9:43 AM ^

You're missing the Gen 2 Durango. It had a channel in the back quarter that ran over the wheel well. Water would run through that channel while you were driving, get to the back of that channel and spin, you know, like a drill bit. It wore through the paint and started rusting where the quarter met the back bumper. Oh, and many of them had the drains in the bottom of the doors sealed up for some crazy reason (an "oops, was I supposed to leave that hole open?" moment). I love my Durango, but at this point it's a race between whether the body will fall apart before the engine blows up. Because they also made the oil drain holes in the engine too small, creating sludge build up.

Other than that, great vehicle!

XM - Mt 1822

May 3rd, 2023 at 9:55 AM ^

we have what are called 'frost laws' where certain trucks/loads are prohibited on certain classes of roads, and in different parts of our state.  i do think the actual tonnage allowed is fairly standard across the country, or at least it was 100 yrs ago when i worked in distribution. 

here is a link: Seasonal Weight Restrictions - Michigan County Road Association (micountyroads.org)

 

mspeters

May 3rd, 2023 at 8:09 AM ^

I can vouch for the mazda 3 rust, but my current '14 mazda 6 is fine. 

Regardless of make/model, an unlimited car wash nov-march is your best defense.

TruBluMich

May 3rd, 2023 at 8:17 AM ^

Live in a state in the red (no politics) or better known as the Salt Belt, then your car will rust unless you wash it daily in the winter.

ChuckieWoodson

May 3rd, 2023 at 9:06 AM ^

My wife has a 2014 Durango in which we get car washes (2-3x a week) in the winter and it has rust on the door panels.  In the past, my old Fords would always rust under the rear wheel wells.  Was surprised to see rust on the door.  I'm a Jeep/Dodge/Chrysler guy but you're not wrong, dunno what it is but they do seem to rust most often than other cars. 

Edit: Just realized you specified silver cars.  Her Durango is... you guessed it... Silver. Ha.