Encapsulated Stainless steel

[Slipknot]

Does stainless steel corode when encapsulated? I hear that if it is NOT in contact with any oxygen, that it can begin to corode. Anyone know if this is really true?

[blackeye]

I have seen stainless corrode while wrapped in plastic-it was wrapped in something similar to saran wrap-machined parts that came from china and sat in our storage yard outside for a few months-some minor pitting. I chalked it up to crappy chinese stainless but who knows

[Fishpart]

Don't know everythign about SS, but it will corrode depending on the actual Alloy. In the 300 series the higher the number the more corrosion resitant the alloy is, 304 corrodes more quickly than 316 for example.

If moisture gets inside an encapsulated piece and can't get out it will probably corrode. Oxygen is the culprit that does the damage.....

[Nebe]

I would think that if you incapsulated it in something water and air tight it would never corrode...

[Van]

Originally posted by Fishpart
Don't know everythign about SS, but it will corrode depending on the actual Alloy. In the 300 series the higher the number the more corrosion resitant the alloy is, 304 corrodes more quickly than 316 for example.

If moisture gets inside an encapsulated piece and can't get out it will probably corrode. Oxygen is the culprit that does the damage.....

This is my field, maybe I can help.
Fishpart is right for the mostpart. However just cause a SS has a higher number does not make it better. Each grade is alloyed for specific reasons. 316 has molybdenum added which makes it more resistant to pitting damage than 304, but not general corrosion. 303 SS is real close to 304 in compositin, but is absolute crap, it is made for easy machining and suks for corrosion resistance. Another for instance,,,400 grades of SS are not good at corrosion resistance either, they are used in medical devices (scapels) and for SS cutters because they can be heat treated much harder than 300 types.

Biggest mistake an engineer made was building a swimming pool out of 304 "HEY IT WILL NEVER CORRODE!" Opps sorry, it cracks in the presence of stress and chloride (if it gets wet) Opps again its a swimming pool so there is agood chance it will be wet.

Anyway, alot depends on the environment. You are also correct that no oxygen=no corrosion. But plastics are not totally airtight. oxygen can and does migrate through plastics and rubbers (thats why balloons go flat). Another worry is the plastizers used in the manufacturing plastics, many contain chlorides (a no-no for SS) and other compounds which contain oxygen. So it is still possible to corrode, but any corrosion that way should stop after a short while, once the chemical are depleted.

But. why would you encapsulate SS anyway???
best off is leave it in the open, it forms its own protective layer in air.
Hope that helps a bit.

That will be 1500 $....please remit.....

[Slipknot]

Originally posted by Van


But. why would you encapsulate SS anyway???


That will be 1500 $....please remit..... Ya right

Thanks!

Some of us plug builders thru wire with stainless and sometimes seal off water intrusion by encapsulating the plug with epoxy, that leaves to front,rear and belly hook attatchment areas exposed.

Here is a thread that caused me to ask.

http://forums.bateau2.com/phpBB2/viewtopic.php?t=4926

[Van]

I see, I think....

But it seems to me that if you left the holes around the wire, and the belly of the plug open, it will eventually dry out. This is good!!

If sealed you could trap water (salt water) inside which would probably be worse. This is bad!!

Does that make sense?

Oh, and forget the 1500, just send plugs.