Machine gray - swirl marks?

alphadog00 said:

I am pretty sure they use only some of the rinse water for washing, but the rinse is clean water.

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Depends on the location. Some places are really strict about recycling that water, some not so much. Some recycle to save money, regardless.

alphadog00 said:

As for dirt and salt. I dont think dirt protects paint. Any dirt left in contact with paint will damage it. If that dirt remains wet without any salt, it will cause rust. Cars from the 70s with more nooks and crannies would have chunks of dirt thrown up into the wheel wells and around the fender lip. The dirt would build up, stay wet and rust. Even in non snow climates.

I think that is why most wheel arches have plastic cladding. No more lip for dirt to collect in to rust.

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Paint doesn't rust. It protects the metal underneath. That's not to say it can't be damaged. Dirt damages it mechanically. UV damages it. Chemicals can damage it. Friction damages it. It even oxidizes. But it doesn't rust like metal.

Pretty much all cars are "undercoated/rust-proofed" these days, so I wonder how big an issue rust is with modern cars anyway. I personally haven't seen any since the 80s, or know anyone who's had a problem since then.

My own biggest concern is how nasty the car looks in the winter when it's not washed.

Puyapim said:

No. The salt dissolves and mixes with the water.

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I see. I guess hand car washes might be a bit different

shadonoz said:

Depends on the location. Some places are really strict about recycling that water, some not so much. Some recycle to save money, regardless.



Paint doesn't rust. It protects the metal underneath. That's not to say it can't be damaged. Dirt damages it mechanically. UV damages it. Chemicals can damage it. Friction damages it. It even oxidizes. But it doesn't rust like metal.

Pretty much all cars are "undercoated/rust-proofed" these days, so I wonder how big an issue rust is with modern cars anyway. I personally haven't seen any since the 80s, or know anyone who's had a problem since then.

My own biggest concern is how nasty the car looks in the winter when it's not washed.

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If the water was not clean or had dissolved minerals like salt, your dirty rinse will leave spots. Maybe west coast car washes use dirty water to rinse, but not on the east coast. None i have been too. I can’t imagine thye would stay in business long. Ccording to this article it has always beeen fresh water, but now they can use reverse osmosis to purify. But pure rinse water is a need. http://www.carwash.com/carwash-water-recycling/

And yes, paint doesn’t rust, but paint is not waterproof and even undercoating is not 100% waterproof. They are both designed to protect the underlying metal to different degrees. Undercoating is ugly but it keeps rocks and dirt from removing the paint. But if wet dirt sits long enough, the paint will be penetrated by moisture and rust will start in the underlying metal. This is how and why you see rust bubbles under paint.

There are plenty of cars in Ohio in the 10 year old category that show signs of rust under paint. And although salt may contribute, i bet there is an area with accumulated dirt that trapped moisture.

I have cut open enough rust holes to find accumulated dirt and debris, so would rather wash dirt off then worry about a wet car on a salt covered road. After all if the salt is doing its job, i am driving on a wet road, and the tires are kicking up salty water anyway.

alphadog00 said:

In my experience rust is more a product of dirt sitting in an area and acting as way to keep that surface wet - more so then just salt. Salt water alone is not the cause of rust. It is the dirt that traps the water and stays in contact with paint. If an area stays wet it will rust even without salt.

And in many climates the mix other things with the salt and the plows kick up all kinds of stuff. I would rather wash all that stuff off my car. Besides when the snow is melting, we are driving through salt water anyway. Washing it off is not going to make it any worse.

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I forgot to mention that here in Toronto, the roadways are covered in physical little pieces of salt, not in liquid form. These little pieces of salt (its often in a powdery form as well from cars driving over it, so it will stick to wet metal which is definitely not a good thing)

When I lived on the Oregon coast for a while, our complex had a makeshift water wash down made of pipe with holes drilled. It was a big square that you drove through while the water was on. That could be easily done with plastic pipe and some spare time if you had the place to put it.

I got a machine grey CX-5 back in Sept. I've washed it a few times since then. I've been using the 'two-bucket' method (one for soap and one to rinse) with a microfiber mitt and then hand-waxing with Meguiar's G18216 Ultimate Liquid Wax. The Meguiar's goes on and buffs up easily (I just buff by hand)... no problem with swirls. I had to do a little extra buffing one day when it was cool (~55F), but I guess that was my own fault. The wax comes up looking really nice, but the really shiny look only lasts a few weeks. Come spring I'll look for something a bit more durable.

Maybe I'm just lucky, but I haven't had any trouble with rock chips yet (I'm at around 4K miles, and I've done a bit of snow/gravel driving). The Soul Red color was my first choice but I couldn't find it with right trim so I ended up with grey. After reading all the complaints about chipping on the red I'm glad things worked out the way they did.