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Rust on Stainless Steel
scootz - 20/6/14 at 07:46 PM

The inside of my Quantum (stainless) had been badly painted when I got it, so I stripped it back using a brass wheel and grinder.

Big mistake.... the panels developed a light coating of rust over the winter. I guess the metal didn't appreciate the use of brass or the microscopic damage caused during the process.

So how can I fix it (without having to repaint!)?

Would a generous coating of pickling paste on the affected panels be enough to break-down the free-iron and other contaminants and restore the metal to its former glory?

A thorough polish to finish off?

Minicooper - 20/6/14 at 08:02 PM

stainless steel does rust, that's normal. Clean it up and polish regularly

David

madteg - 20/6/14 at 08:43 PM

Sounds like 304 stainless or a cheaper grade, be very carefull as pickling paste will turn it green. Try on a spot you cannot see.

madteg - 20/6/14 at 08:46 PM

Just a thought but had the wire wheel been used on mild steel before, you could have contaminated the stainless with mild steel of the wire brush.

Chris_Xtreme - 20/6/14 at 09:21 PM

Both of my xtremes lived/live outside a lot of the time and didn't/haven't rusted.

Which bit is rusting? Got a pic?

britishtrident - 21/6/14 at 11:28 AM

quote:
Originally posted by madteg
Just a thought but had the wire wheel been used on mild steel before, you could have contaminated the stainless with mild steel of the wire brush.


As above even swarf deposited from grinding normal steel in proximity to stainless can cause staining of cheaper grades of stainless.

scootz - 21/6/14 at 12:13 PM

Hadn't used the wire wheel on anything else.

It's definitely as a result of my meddling as the car was 7 years old when I got it and it hadn't a spot of the brown stuff.

I've been reading some techie papers and a good chemical clean may restore the surface. Quantum use pickling paste on the tubs after they've welded them, so I guess it's worth a try.

Chris_Xtreme - 21/6/14 at 12:23 PM

Just in case, you are not talking about the side panels are you, rather than the tub its self? I'm sure your not....

scootz - 21/6/14 at 01:34 PM

The interior panels in the cockpit (floor, rear bulkhead, tunnel).

Chris_Xtreme - 21/6/14 at 01:36 PM

first extreme had no protection on the floor.. no rust at all... the v8 i have now is fully carpeted! so who knows what is underneath!

good luck.

scootz - 21/6/14 at 01:45 PM

You'll be fine Chris. It's my second one and the neither had any rust in a combined period of 10 years.

This has only come about because of the 'aggressive' method I've used to clean the panels.

I'll do a bit more with the wire brush to get all the rust off, chemically clean it, wash it, then finish with a good polish.

907 - 21/6/14 at 05:52 PM

Are you sure your brush is brass?


I bought some small "brass" brushes, and as you see from the pic they stick to a magnet no prob.

"All that glitters is not gold."


Paul G


Brass? I don't think so.
Brass? I don't think so.

Bigheppy - 21/6/14 at 07:22 PM

Have a look at this in particular post no3

http://www.worldseafishing.com/forums/boat-owning-equipment-maintenance/2307370-what-stainless-steel.html

steve m - 21/6/14 at 07:53 PM

If I was to find rust on a stainless part my first call would be to the company that supplied the part,
My Father in law, who has been in the metal polishing trade for 50+ years has added, if a stainless pieceof metal has gone rusty,
it aint stainless, END

Steve

britishtrident - 21/6/14 at 08:26 PM

The cheapest grades of stainless steel used to make contract grade stainless steel sinks and the like were dubbed stainless iron by my metallurgy lecturer.
This stuff can develop rust surface stains very easily
On more than one occasion I have had to clean a sink with phosphoric acid after cleaning steel parts in the sink.

[Edited on 21/6/14 by britishtrident]

Slimy38 - 22/6/14 at 09:28 AM

quote:
Originally posted by steve m
If I was to find rust on a stainless part my first call would be to the company that supplied the part,
My Father in law, who has been in the metal polishing trade for 50+ years has added, if a stainless pieceof metal has gone rusty,
it aint stainless, END

Steve


I've had plenty of 'stainless' exhausts go rusty, albeit a lot slower than a mild steel equivalent. I was under the impression that the lower grades of stainless can still rust? But conversely the higher grades of stainless can be more brittle? Or is that just marketing bumph used to sell cheap and nasty exhausts?

scootz - 22/6/14 at 11:46 AM

It may not be the stainless that's rusting on my chassis... it may well just be deposits from the 'brass' wheel.

Clean forgot that the roll hoop is mild steel and I attacked that first with the wire wheel before hitting the panels. Oops!

So I'm hoping that a good chemical clean and polish will indeed do the trick!