rust question

[onewhofarts]

Hello
I have a milkcan which took some abuse as regular welding instead of argon welding that made it rust.
there are two parts were it got rusty , the bottom , that was cut off , and a new stainless bottom will be welded to it.
the other point which is located on top the question is about. where you can the coupler , inside.
will it be enough to redo the rust part at a professional welder , or it eventually will rust anyway ?

[Kareltje]

Still no answer?
It is not clear what you want to do with your can. Brew or boil?

I have the same problem: when I took up distilling again, a friend brought me a ss can with a added outlet and rust on the connection.
I do not know about welding and I do not know if it will eventually rust off.

But for the time being it it hardly a problem.

When you want to use the can as a boiler, do not fill it above the coupler. But that is wise anyway, for in distilling it is wise to have enough headspace in the boiler. The vapour is hardly acidic or basic, so will not attack iron. And after the run you can make sure it is perfectly dry: iron does not rust when it is dry.
When you want to use the can as a fermenter, just do not fill it above the coupler. That is a bit of a loss of volume, but rather safe than sorry. Iron in food is not a real problem, for it is not toxic. And even if it gets into your wash it will hardly be a problem, for during distilling it will (mainly) stay in the spent lees. But the fermenting wash may be acidic and attack the iron in the connecting weld. Not in a day or week, but after repeated use. Even the moist air above the fermenting wash will attack the iron.

In both uses you have to monitor the status. As long as the connection is strong enough, you can use the can as a boiler and as a fermenter. When it gets thin, you have to solve this problem or find another use for the can.

Do not worry about iron in your wash or distillate: it is not toxic and it is even necessary in your blood to be able to breathe.

[cranky]

Look up how to repassivate stainless to treat the rust.

[still_stirrin]

...will it be enough to redo the rust part at a professional welder , or it eventually will rust anyway ?

Unfortunately, the rust is a "cancer". It will continue to pit unless it's excised. Your pro weld shop can cut out the rust and patch with clean 304 stainless. Or, you could just "tough it out" and continue to use it. But be sure to clean it and dry it thoroughly. Hopefully the rust growth will be retarded (like the welder who welded it using a stick welder instead of TiG).

Appologies to all you pro welders out there. I know you wouldn't weld stainless without a blanket gas or the correct filler rod.
ss

[Shine0n]

304 stainless will rust! At work there is a lot of it I see every day that is rusty, 98% of it is just minor surface rust though. May be from the salt in the air being at the ocean shore but that's what I know. I have welded many things 304 with stick and haven't had any issues but have also seen plenty of stuff come into the yard with rust. Don't play on the wrong side of caution either, make sure its done correctly and make sure it's clean. Good luck

[Hound Dog]

Look up how to repassivate stainless to treat the rust.

+1. Clean it with a Scotch Brite pad ND passivate with a citric. It will be ok.

[The Baker]

Hi,
This from one who has no experience at all of welding, so....

But if you are going to replace the bottom, and supposing you want to heat from underneath (gas?)...

And if it is possible...
Heavy duty copper would heat much more efficiently.

Geoff