Rusty Element

Long story short, I cut too large a hole in the HLT cooler, but had access to some stainless steel to patch it. Everything is fine with leaking but now the the stainless seems to be developing rust. Does anyone have a solution to this? I would be happy to not have to buy a new cooler.

Use non metallic abrasive like emery cloth to pacify stainless steel. John Palmer talked about it on Brew Strong.

Given the right conditions, 400 series stainless will rust. It can also be slightly magnetic too.

You might want to see if you can check the material of the pieces, and change to 300 series if possible.

After further review, it is the heating element that is causing the rust. The portion of the element that goes into the base. The base is rusting. I am concerned about future corrosion.

My new thought is to apply epoxy to the top of the base of the element so it is water tight. Since this is the HLT, the temps will never go about ~180. I know many epoxies are are food safe once cured, so I think it should be safe. Ideas?

How harmful could a small amount of surface rust in a HLT be? I wouldn't be too worried, just scrub it up once in a while, make sure you dry it out well after using it to discourage rust. What is the nut made of? If it's not SS it could be causing the rust on the panel.

hit it with some bar keepers friend and a green scouring pad to repassivate it

i dropped an aluminum anode in mine after the same thing happened (did the same thing for the boil kettle). i bought one at home depot. it was kind of nasty looking, so i covered it with aluminum foil for something a little cleaner looking. rust problem solved.

p.d.

I've read magnesium is supposed to be the better anode. Plus there something weird about going all stainless and then dropping in a hunk of aluminum. I also read one guy used an aluminum nut to hold in his heating element so he just replaces that nut every so often and it keeps other parts from rusting.

-OCD

beerocd said:

I've read magnesium is supposed to be the better anode. Plus there something weird about going all stainless and then dropping in a hunk of aluminum. I also read one guy used an aluminum nut to hold in his heating element so he just replaces that nut every so often and it keeps other parts from rusting.

-OCD

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yeah, magnesium's better. but practically speaking, these things are meant for hot water heaters where they have a much larger surface area to protect. my guess is that in this context, the difference in metal type doesn't matter. our HLT's and boil kettles also don't have liquid in them 24 hours a day for years on end.

unless a system is 100% stainless, you'll get rust. heater elements aren't stainless.

a side note, i believe i read that the protective anode has to be in direct contact with whatever you're trying to protect, so i just make sure the end of the anode is sitting on the element/locknut.

p.d.