Painting rear suspension coils

I just purchased new rear spring coils for my 2003 325 I. I am planning to re-paint them with a few coats of rust-oleum paint to stop any rust that may form. My old springs broke after rust penetrated the paint. Any thoughts or ideas?

I would worry about it. All new springs come painted. It wasn't corrosion that broke the rear spring, its a common problem on our cars. It happened to me at 37k miles and I replaced it with a new OEM one. It was on the car until I put new Eibach springs on at 96k miles. Just replace both rear springs and you should be fine for quite a while.

Rust penetration has nothing to do with spring failure. Stress does.
If it's not something about cosmetical mod, I suggest you to leave it as is. You're just wasting money and time.

You are correct that it was rust that broke your OE springs. Those springs however were also faulty which was the combo that led to the failure.

However as stated, springs already come painted. If you paint them again, the paint only going to crack when the springs are used as that paint isn't made to flex with the springs.

Don't worry about it. Take a look at older BMWs such as e36's and e30's. The rear springs are often completely rusted on the exterior but the springs themselves are still fine.

oem spring are going to be powder coated. which are much better and stronger paint protection than any basic rattle can Rust-oleum . I'd just make sure you have decent bottom rubber spring pads. When the spring pads wear through the metal and touches the aluminum it can exacerbate premature failure. But stress is the main culprit.

Originally Posted by Alex323Ci

oem spring are going to be powder coated. which are much better and stronger paint protection than any basic rattle can Rust-oleum . I'd just make sure you have decent bottom rubber spring pads. When the spring pads wear through the metal and touches the aluminum it can exacerbate premature failure. But stress is the main culprit.

A) Rust is a byproduct, corrosion is the reaction.
B) Corrosion does weaken the integrity of the springs and thus can shorten the life and lead to them breaking a bit sooner than may normally occur.
C) Two dissimilar metals touching can create a corrosion cell on its own, so definitely keep a good spring pad in place if corrosion has you worried.

Originally Posted by Arsevader

You are correct that it was rust that broke your OE springs. Those springs however were also faulty which was the combo that led to the failure.

However as stated, springs already come painted. If you paint them again, the paint only going to crack when the springs are used as that paint isn't made to flex with the springs.

Don't worry about it. Take a look at older BMWs such as e36's and e30's. The rear springs are often completely rusted on the exterior but the springs themselves are still fine.

I had an E36 M52 21 years old. Rear spring went at 240K. Can't complain. God that was a good motor. Should have kept it and had it refurbished instead of buying the one I have now. It was a far better build quality back then.

Spray paint on a flexing spring will flake off. The coating as to be flexible.

I know this is an old thread, but since i'm about to replace my rear springs, i was thinking of plastidipping them. Should be able to flex easily enough, and provide at least some protection, and thereby extending spring life. Hopefully by a substantial amount.

Thoughts?

Originally Posted by ShaTR

I know this is an old thread, but since i'm about to replace my rear springs, i was thinking of plastidipping them. Should be able to flex easily enough, and provide at least some protection, and thereby extending spring life. Hopefully by a substantial amount.

Thoughts?

I don't think so. The springs are under constant blasting of road debris kicked up from the tires. Think of them bring lightly sandblasted everytime you drive. Plasti dip will not withstand this at all. Also once plasti dip starts to peel it just keeps going.
The only coating durable enough to bend, as well as withstand the dirt and rocks, is powder coating.

Originally Posted by peytonracer4

I don't think so. The springs are under constant blasting of road debris kicked up from the tires. Think of them bring lightly sandblasted everytime you drive. Plasti dip will not withstand this at all. Also once plasti dip starts to peel it just keeps going.
The only coating durable enough to bend, as well as withstand the dirt and rocks, is powder coating.

interesting theory. The argument would then be, 'my rear bumper and lower front door, which gets hit by much more tire kickup than a spring, suffers very little damage'.

I think the coating that's on the springs, whether paint or powder, will eventually crack off due to stresses. My theory is that the plastidip would hold that chip in place without breaking (perhaps bulging out a bit), thereby protecting the raw metal from the elements. Hopefully, this would hold off corrosion, at least for a while. Again, just my theory.

Originally Posted by ShaTR

interesting theory. The argument would then be, 'my rear bumper and lower front door, which gets hit by much more tire kickup than a spring, suffers very little damage'.

I think the coating that's on the springs, whether paint or powder, will eventually crack off due to stresses. My theory is that the plastidip would hold that chip in place without breaking (perhaps bulging out a bit), thereby protecting the raw metal from the elements. Hopefully, this would hold off corrosion, at least for a while. Again, just my theory.

no because the door and bumper aren't in constant flex.

i think it has to do with holding in moisture for corrosion aswell.

if you're talking about the plastic-dip spray i doubt that would hold up. now if you're talking about the industrial tool dipped type i can not say. it would have to be perfectly clean of any corrosion prior to coating.
it could help some. not sure if it would be worth the effort.

Originally Posted by Alex323Ci

no because the door and bumper aren't in constant flex.

i think it has to do with holding in moisture for corrosion aswell.

if you're talking about the plastic-dip spray i doubt that would hold up. now if you're talking about the industrial tool dipped type i can not say. it would have to be perfectly clean of any corrosion prior to coating.
it could help some. not sure if it would be worth the effort.

Well, we're talking about new springs here. I mentioned i need to replace my spring(s).

The spray is the same stuff, just goes on thinner. I would probably go with the brushed on stuff though anyways.