304 SS rusting in two weeks?
 

EDIT: The question isn't if 304SS ever rusts. We all know it does. This, however, seems extreme for being installed for TWO weeks.

The vendor who sold me my exhaust would have be believe that my tips, which he assures me are 100% 304 SS (because they're not magnetic.. His reason) are rusting due to over exposure to elements.

The exhaust has been installed for TWO weeks. There has been one snowstorm, during which my car sat nice and comfy in the garage. It's always in the garage at home.

It has not been driven through heavy snow and the tips certainly haven't been sleeping in snow.

Anyone believe there's any possibility of this happening in such a short timeframe to 304 SS?

http://i.imgur.com/dflEe27l.jpg

yes, 304 ss rusts

Any pictures?

I see a pic? http://i.imgur.com/dflEe27l.jpg

@Anorax http://www.meganracing.com/new/tech/...inless%20Steel

Two weeks? No man, that's crazy talk. It probably has some iron contaminants on the surface that need to be cleaned off. If it continues to happen immediately after that, you got some bad 304SS or some crazy environmental exposure going on.

Check if a magnet sticks. Vendor is correct about that.

If it doesn't stick it's 3xx series stainless.

There are some possible causes if it is 3xx.

First 304 or any stainless isn't perfect. They resist rust/corrosion and there are levels. 409 is terrible, 304 is better, 316L is better still, 321 is superb at high temperatures. Rolex watches use a 9xx stainless that is even better. But each step in the corrosion resistance ladder costs money. 304 is the entry-level of the better 3xx series.

Second is chemistry. Steels hate salt and water and air all mixed together. Something about electrolysis makes oxidizing easier. 316L is better against this and is commonly referred to as 'marine grade' because of it. Dirt can keep salt and moisture on the metal longer which gives a longer chance for rust to form.

Third could be contamination during manufacture. If it was polished with some scotchbrite or a wire wheel that was previously used on mild steel, it can embed small particles of the previous material on the surface that will rapidly oxidize. You can make aluminum 'rust' by doing this.

Ouch! That sux. Sorry for your loss.

Is that salt on the rear of the car? If so, problem solved.

No, they don't salt the roads here

Which exhuast is that btw?

Intentionally leaving that information out to focus more on the possibility of 304 SS rusting out in two weeks. Sorry, not trying to stir any pots, just get information.

Works exhaust system

Pot stirred. :popcorn:

not really though. If you think about it, most products have at least a few bad products leave the shelf (even when using strict manufacturing processes and machines to manufacture items).

I wouldn't necessarily count out works exhaust for one item rusting. However, I would probably ask them to compensate me for replacing the tips with some that will not rust like these have.

idk man, i have 304 stainless and have driven during this heavy snow season and on consistantly salted roads and have had no rusting at all.

but i do wash the undercarriage pretty often ~1-2 weekly

as Dimman pointed out any free iron particles on the surface of the metal can cuse rust (see threads on rail dust rusting white painted cars)

For stainless 300 series "best Practice" is to have the parts passivated after cutting/forming/welding. However passivating is not a process available in house at 99% of fabrication shops.

If a shop is both careful AND lucky, you can often get away with careful surface prep and keeping different polishing/buffing/grinding wheels, scotch-brite, sand paper etc etc for different materials.

I atleast find it refreshing that you aren't on here bashing and would rather address the problem at hand.

****If it was on my car, I would take the assembly off and start with a fresh piece of SS wool (extra fine), and roughen the whole polished tip, then polish it with a polishing wheel or buffer and some fine rouge (green or white) to get your polish back, this should get any surface contaminants out...but having those things handy and not is usually the difference****

Ran my Nameless all through winter and have had no issue like this with the tips or piping.

And you got considerably more "elements" then I did out here on the plains of the Rockies.

Severely over-salted roads, plenty of rain, occasional snow. Nice humid climate! The perfect breeding ground for rust. I think I sheared EVERY bolt on my WRX when I did exhaust, after ~8 years of ownership. Going to try and get the BRZ buttoned up exhaust wise before next winter.

http://i.imgur.com/dflEe27l.jpg
Are you being sarcastic? That definitely looks like salt and its all over the place.

also, just because its 304SS doesnt mean its 304SS. ask the manufactor for their batch certification. you could have a bad batch of 304SS with lower than usual chrom content.

Anorax where is your Location? That looks like salt on the ground, and all over the bumper, and the spot pattern on the exhaust tip looks like it has the usual salt corrosion effects. If you live anywhere that a parking lot could have salt on it thats all it takes. Either that or you live near a body of water with high salt content. Like others have said, the surface may have some iron contamination. Try cleaning it off with a metal polish.

Are the exhaust welds Rusting?

Most stainless will get a petina over time from water and air and temp.

The tips could be a lesser 3xx Stainless and possibly why it rusts faster?

Looks like it isn't the tip rusting but random road grime, brake dust, and other junk picked up during winter months that is rusting, especially with all the salt/brine used on roads.

Since you have a white car. Take a very close look at the paint. I bet you will also see "rust" spots in the paint. While the car isn't rusting, the material picked up from daily driving that is stuck on the paint is rusting. Most the time you can get it out with a nice hand car wash but other times it requires clay bar and some polishing.

Can look like this:
http://img.photobucket.com/albums/v4...g?t=1200265285

To me that looks like what is happening on the tips. Hard to say though without me taking a rag and scrubbing the tip down.

I'll acknowledge that my work parking lot might have some salt, I can't say for certain. But again, that much in two weeks time?

I'll be getting some Eagle One Nev'r Dull today (hopefully) and seeing what comes out.

Silver car, actually and I intend on thoroughly cleaning the tips today if I can find the cleaner I want.

Hopefully, you're right.

Then I guess it'll be a matter of how long until it does it again, or if (if I'm REALLY lucky).

this isn't AeroSpace, it is highly doubtful that the "heat lot number" is going to be tracked thru any processes outside the original foundry.

and this isn't the 50's anymore the chance of getting "bad" 304 is not very high. heck 90% of the 302 I buy meets the 304 standard requirements also.

Anybody knows what the stock tips are made from (not trying to high jack but just for comparison's sake)... they looks pretty damn good after a whole winter.

It's actually a fair point, as my stock exhaust were on the car considerably longer throughout winter and I know they don't look like this.

Though, if it's as FT-86 SpeedFactory suggests (road grime, etc) the stockers don't stick out much either.

ft-86 does bring up a good point. When looking at the pics, I'd say there is a fair chance that could be your problem. I'd take care of it ASAp, so that it doesn't ruin the metal tips

Thats looks pretty bad for 304...

Most Chinese mfgs don't know what metal grade they are getting, they only guess and believe what they are told by the foundry. Back when I was mfg exhausts in China in the early 2000's the whole building boom resulted in a shortage of 304, and they switched us to "302" which wasn't really 302 and ended up rusting. So to be fair the reseller probably didn't know what they were getting but I'm willing to bet you have a metal with a lot of impurities in there....

I feel your pain and I myself wouldn't be happy with that. Far too often, people these days want to make you feel like you should accept defects as "normal". Nothing normal about paying good $$ (hard-working self-earned $$) for something with abysmal quality. Ask the manufacturer to make it right.. at least the tips. I have a Crawford axleback that has been on for more than a couple of weeks and it is just as good as the day it was installed. Oregon doesn't salt, but we don't exactly have the friendliest environmental conditions.

Have you sourced in China before? Buying 304 here in the states is very different than purchasing "304" in china.

Like most here , that should not rust and they are right that just because the manufacturer states its 304 it might not be or be complete shit. I knew a guy interning somewhere in chicagoland who was inspecting our aftermarket/oem wheels for the metal makeup. He said it was scary what wasn't in it and what was compared to what the manufacturer claimed it was.

But to me, it takes a lot more than 2 wks of salt to make 304(good) rust that fast.

Ps- i'm a machinist

So then you should be aware of the 3 phases of iron crystal structure and that the product being non magnetic exemplifies that it is in fact of one specific crystaline structure......but you are completely unaware of surface contamination?

:popcorn:

Perhaps we should get back to how magnetism is actually detected?

I am NOT a metallurgist but I have paid good money to a lot of metallurgists and material failure scientists for everything from camshafts, valve caps, to seamless extruded piping used to mfg both titanium and SS exhaust systems. As I understand high impurity levels as well as the desire to "half ass" production from the foundry (and yes I have toured seamless tube foundries) can cause this type of rust situation. I have seen this problem myself and shipped entire containers back because of it. On the flip side I have had exhaust systems come back due to defects, etc. from all over the world, some places clearly winter conditions with a lot of salt, and all of the product we produced never exhibited that kind of coating. So as a betting man I would say source material is impure or not truly 304. Maybe I"m wrong, but I've built and sold a lot of exhaust related components...

Two pages of people talking about a dirty exhaust tip with a couple rusty water spots...

Sounds like diarrhea.