Does Phosphor Bronze rust?

[SpyderJon]

Howdy all! I'm not sure if this has been asked directly or not. I know that a lot of us use/upgrade to PB washers, but I've heard they rust. Interesting to me because I didn't know bronze rusted (just thought it tarnished). Anyhoo, is this the case? If they do, why not use nylatron washers, or do PB washers last that much longer? Thanks!

Sincerely,
Anthony

 

[mete]

Rust is iron oxide, therefore bronze doesn't rust but will corrode or tarnish.If you have just a bit of lube in the joint it isn't going to be any problem.

 

[ckl]

There is no metal that will not rust/corrode... Even gold,silver or stainless steel can be corroded...

I think bronze has a good corrosion resistent and also wear resistent. (those ancient chinese bronze swords!)

 

[Planterz]

Unless you store a the knife for a very long time, with absolutely no lube or other protection on it, you won't have to worry about your washers corroding. Even if it's bone dry, but you use it occasionally, it'll stay corrosion free. Take a look at an old doorhandle or a statue of Abraham Lincon. Parts of it will be badly tarnished, but other parts, ones that are frequently touched (for some reason, people like to rub Abe's nose) will be smooth and shiny.

 

[Gollnick]

It will tarnish to a little bit darker color, but it won't rust away like iron does.

 

[SpyderJon]

okey dokey! I wondered about that. One of the reasons I asked is because Mr. Cliff Stamp was mentioning something about the washers on his sebenza rusting and affecting the smoothness of operation. I don't want to start another sebenza thread, I just thought I'd explain why I asked- Like I said, I hadn't thought bronze would "rust" per-se, but rather tarnish.

Oh, and I thought Pure gold wouldn't rust or oxidize, true??

-Anthony

 

[Gollnick]

Oh, and I thought Pure gold wouldn't rust or oxidize, true??

Gold Oxidizes. The most common oxide is Au2O3. But, all gold oxides are unstable (Au2O3 is at least somewhat stable at room temperature) and even getting gold oxides to form in the first place is difficult laboratory exercise. Of all the metal elements, gold is by far the most difficult to oxidize. There is no known natural occurance of gold oxide; they are purely laboratory creations.


Aluminum, by the way, is the other extreme. Every piece of Aluminum you've ever seen in open air is competely covered with rust. Fortunately, Aluminum oxide has an extremely tight, tough crystal structure. Once a layer a few molecules thick forms on the surface of a piece of Aluminum, the surface is sealed and no further oxidation will happen. Aluminum oxide is also clear. How hard is aluminum oxide? Well, it has several other names. Under the name Corundum, it's used as an industrial abrasive. Under the name Sapphire, it's a gemstone in the league with diamond for hardness. So, not all metal rusting is a bad thing and not all rusts are the weak, powdery red substance we commonly call rust which is iron oxide.

 

[Cliff Stamp]

I hadn't thought bronze would "rust" per-se, but rather tarnish.

It just depends on the extent of the enviroment, steel essentially tarnishes if the oxidization stress is low, it just discolors and takes a patina. It takes a lot to induce significant damage to the bronze washers, I soaked it in salt water, interestingly enough the blade didn't oxidize at all.

-Cliff