Decided to scratch up some peoples' clear coats for a little science experiment?

Could I have damaged the cars even though I saw no signs of damage?

It would be nice if someone else with knowledge would chime in here. If this damages cars, then I want to know, so I can stop doing it in the future.

As long as the car is dirty, then contact with it can damage the top coat. This is a lot more true if you need to drag or scrape the magnet to remove it.

Unless the cars are perfectly washed and clayed, even running a clean finger over a car is likely to introduce scratches. I just wouldn’t ever touch someone’s car.

You can look up people even trying to detail their cars to make them cleaner and end up leaving “love marks.” It doesn’t matter how soft the thing you’re using is. It’s because the car has contaminants on it and by rubbing anything on the car, those contaminants end up scratching everything. It’s like when you’re at the beach and you’re trying to remove sand off your skin. You’re probably not aggressively rubbing it off or using much pressure but it still hurts. It’s the same with cars, it’s just that the rocks aren’t as visible to you. They will leave swirls and scratches though… which become noticeable.

I’ve had people just lean against my car when it wasn’t completely clean and completely ruin the paint requiring an entire 5 stage detail.

> I’ve had people just lean against my car when it wasn’t completely clean and completely ruin the paint requiring an entire 5 stage detail

Assuming this is true, it seems like something has gone badly wrong somewhere in this process.

Why can't cars have paint that survives being "leaned on"

I think the person you replied to probably just has a different definition of "completely ruined" than you or I.

Visible marks from over 20ft away. You tell me.

Yeah we are talking pathological territory here. Car paints need less love than their owners need therapy if they have to "detail" their car every time a cat jump on the hood to enjoy the warmth.

If we're taking it this far then driving on the highway is like sandblasting the paint with dust and you do that without even thinking about it.

Cars spend a significant amount of time outside and they depreciate so quickly it just doesn't matter. One shouldn't expect a paint to stay perfect the same way we expect our skin to wear and age over the years.

I don't even know what a 5 stage detail means but I can safely say you are overreacting. A car is just a tool and a rando putting a fridge magnet or leaning against your car once in a while is just completely negligible compared to the amount of shit a paint is exposed to when driving it. Sand and dirt do not ask for your permission either.

It won't really matter all that much, but it will have done more than 0 damage to the paintwork (since metal is hard and paint is soft). Worth noting that drivers are touchy and emotional, and can't be trusted not to murder you over perceived slights, so it's safest to stick to doing nothing. Stuff something under the windscreen wipers if you really must, and even that is risky.

Unfortunately, yes. Dropping a magnet onto a car and pulling it off, especially if not recently cleaned, will damage the paint to some degree. Maybe not enough for an average person to notice, but you really shouldn’t do this to other people’s cars.

Some people will get snide about anyone who cares about their car’s paint, but as someone who once bought a car I had to save a long time for and spent a lot of time with car care products I would be very sad if I saw you drop a magnet on to it and then pull it off without a second thought. Please don’t.

Also, the paint on cars isn't just cosmetic. It's what keeps the metal from getting wet and then rusting.

Aren’t all modern cars galvanised?

The unpainted parts.

Are you saying the unpainted parts are or aren’t galvanised?

What metal parts of a car aren’t painted? Or more broadly: coated.

The "unpainted" parts are galvanized. Galvanization is essentially zinc paint (with no dye). For the painted parts, the paint serves the same purpose, which is why it's important not to mess it up.

You think hot dip galvanising, zinc electroplating, zinc rich primer, and zinc rich top coats are the same?

Jotun would like a word with you.

I'll avoid doing it from now on.

I'm curious, how did you make it this far in life without realizing that paint is delicate and scratches easily? Do you have untreated brick walls in your house or something?

A flexible fridge magnet is probably fine.

Seems like everyone here is assuming you used a 40lb neodymium magnet you dropped in the dirt first.

I like to assume the best in people.