Another keggle rust thread.

[CrowbarKarl]

You can repassivate with citric and ascorbic acid in hot water like we do for SS repassivation after welding or grinding and breaking the surface passivation. A 50-50 mix of 1 Lb acid blend in 4gallons of water, heated to 180 degrees, and left to cool for about 6-8 hours will extract the soluble iron and rebuild the oxides to protect the stainless steel where it has been heat affected. This is slower than the nitric acid method but safely do able by the homebrewer, and is the method of choice in the food and beverage handling industry these days. You will only need to cover the weld area, not fill entire keg as only weld or grinding/ polishing area needs attention.

Not to wake a thread from the dead, but it is ok to leave copper and brass parts such as a copper diptube and brass nut while repassivation of the keg? My HERMS also has a copper coil in the HLT and didn't know if that needed to be removed as well.
Cheers!

 

[theQ]

You can repassivate with citric and ascorbic acid in hot water like we do for SS repassivation after welding or grinding and breaking the surface passivation. A 50-50 mix of 1 Lb acid blend in 4gallons of water, heated to 180 degrees, and left to cool for about 6-8 hours will extract the soluble iron and rebuild the oxides to protect the stainless steel where it has been heat affected. This is slower than the nitric acid method but safely do able by the homebrewer, and is the method of choice in the food and beverage handling industry these days. You will only need to cover the weld area, not fill entire keg as only weld or grinding/ polishing area needs attention.

Starsan is an acid, will that work as well ?

 

[acidrain]

Not to wake a thread from the dead, but it is ok to leave copper and brass parts such as a copper diptube and brass nut while repassivation of the keg? My HERMS also has a copper coil in the HLT and didn't know if that needed to be removed as well.
Cheers!

Probably OK, but when in doubt, I would remove them.

Starsan is an acid, will that work as well ?

No