A different sort of rust removal...
 

I've heard a kabajillion times about removing rust from chrome. We all have.

But what about removing rust from metal that may not have been chromed?

For example, (and only example) a Varsity seat post or seatpost clamp? Parts like that?

Is there a way to clean the rust off of that, or is it just sandpaper and wax?

-Nick

Oxalic acid, lye(sodium hydroxide), phosphoric acid, bead blasting, sandpaper and steel wool

I've used a strong, hot lye solution to derust an engine block.

If you use lye, use gloves and eye protection and an apron. Use with caution. Rinse everything well, then wax or prime before the part can flash rust.

Oxalic acid eats rust. Doesn't matter what surface the rust is on. That stuff did a fine job for me on some steel rims of a Varsity using a wallpaper tub tray and rotating them a few times for a few days. Safer to use gloves around that the oxalic acid as well.

NAVAL JELLY ... will work when others don't. It's been out for decades. Years ago I used it alot, part of my job at the time was to take the rust of things. Auto parts stores, home/ hardware stores have it. It's pinkish & comes in a jar.

Does naval jelly affect paint at all?

My little jar of Naval Jelly says that it contains phosphoric acid and that it should NOT be used on aluminum or chrome. Works great on iron or steel.

I don't know what it does to paint… suppose it might depend on the paint. Just ran a little experiment on the corner of a toolbox and the surface looks fine but a little bit of color did transfer to the rag. I'd guess its not going to strip the paint but won't be great for the finish. YMMV.

I have used PB Blaster or WD-40 sprayed on the part and then scrub it with a wadded up piece of aluminum foil. Aluminum is soft and won't damage metal or chrome - like steel wool can, but is abrasvive enough that in combination with the WD-40 or PB cleans rust pretty quickly. It's great for small pieces and small areas of rust damage.

Aluminum foil is a poor solution. The soft foil actual fills the pits when you rub it over the chrome. The problem is, it doesn't actually remove any rust, which still eating away at the metal under the foil. However, it does improve the looks with little effort. It's a quick and dirty flipper's trick, but not in the same league as the other solutions mentioned.

Hmm, I'm not really working with chrome or nickel, and OA can be a bit of a pain with storage and stuff... I'm thinking since it's just steel I may try naval jelly... Yeah?

If its just steel, Naval Jelly is a good sauce… I've scrubbed it into threads with an old toothbrush and then rinsed it off and dried it 10 minutes later.

Just a few notes from the bottle that may be of interest…

If aluminum from wadded up aluminum foil does get into pores and pits on the steel part you are de-rusting, you are also just promoting more corrosion in the future because the dissimilar metals will react with each other when it encounters any moisture.

Chombi
84 Peugeot PSV

green scotchbrite pads work great, but they do leave very small scratches. this can be a very cool thing if you scrub in the same direction throughout and perpendicular to the item. for example, here's how it looks on a titanium frame. you can achieve a similar effect on seatposts.
http://farm4.static.flickr.com/3629/...01bdbe3e_b.jpg

I use Naval Jelly all the time--it's great stuff. I've even used it on chrome, although they don't recommend it. I'll just leave it on for a shorter period of time, and give it a quick scrub and rinse. Of course, this is on relatively low-quality stuff, where I'm not terribly worried that something will go wrong.

Washing powder, tub of water, 12v at 1 amp.

It will remove paint as well.

http://www.bikeforums.net/showthread.php?t=520550

The aluminium foil particles will corrode long before the steel will. Aluminium is lower on the galvanic series than steel and will not cause the steel to corrode. It's the other way 'round. The aluminium particles will help to protect the steel from contact with the oxygen in the air or water, which is what actually causes most of the corrosion in steel. If and when the aluminium corrodes away, it's a simple matter to repeat the process.
Steel and aluminium will corrode eventually no matter what anyone does to them. Paint, wax and plating etc. only slow the process to generally acceptable levels.

If its just steel use an S.O.S. pad .It takes the rust right off.

And it leaves scratches that will be more prone to rusting.

here i disagree. the architect in me kicks in and says aluminum and steel don't play well together. i've seen aluminum roofs that were damaged and the replacement roofing was galvanized steel. the steel was below the aluminum in the slope of the roof. the steel rusted like crazy. runoff from the aluminum causes serious oxidation of the steel, even galvanized stuff.

Wow! I picked up a bottle of that naval jelly stuff, its amazing! I was too lazy to deal with OA on this bike, since it was a dumpster find and I just wanted to get it on the road, and I didn't care too much if the paint was kept intact, so I figured I'd give it a try. I didn't even have to let it sit on the recommended 5-10 minutes, the rust started brushing off almost instantly, with no obvious damage to the paint

Before:

http://img126.imageshack.us/img126/9592/photo2n.jpg

After:

http://img4.imageshack.us/img4/6785/photonvh.jpg


I only applied it to that big area of rust, there's still some spots that I'm going to have to return to

thanx for the post!

i was wondering what i should do about the rust on the bridgestone that i found!

Naval Jelly is just phosphoric acid. It's been a while since I was a Corrosion Control Rep in DOD but it converts ferris oxide (rust) into ferric oxide. It's a great base for primer and paint. Another commercial product that works is called "Extend". The US Navy uses it on a lot of steel applications.

Chrome doesn't rust. In fact chrome cannot release electrons or corrode in any fashion. What you're seeing is rust coming through a thin plating of chrome. Chrome is cathodic to steel and will cause steel to rust (given the proper or rather improper environment).

The shipwright in me says that anelectrolytic reaction took place between the zinc coating on the steel,the aluminium and the steel. Zinc being the least noble of the three metals will corrode first and expose the steel to oxygen which is what has caused the corrosion. Aluminium is in turn less noble than steel and will corrode next if the electrolytic reaction continues. Steel and aluminium of course will corrode even without an electrolytic reaction.
Ships and boats which live in the water have sacrificial zinc anodes for this reason.

Exactly.