Rust in new kettle

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cchristoph

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Have a new spike 15G. Put tap water and let it sit at the 5G mark to make sure there were no slow leaks in my threads. Went to empty it today (it’s been about 4 days) and there were small rust spots on the bottom around the size of a BB. They came off for the most part using distilled water and pbw but wasn’t easy to get gone.

Is that normal or what could I look for that may have caused it? Was also hooked up to a riptide pump and two sections of hose with cam locks.

Thanks in advance.
 

day_trippr

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It would be sad to think a brand new kettle developing rust spots was "normal", but bottom line, it sounds like that kettle needs to be put through a(nother) passivation cycle.

Pick up enough powdered citric acid to fill your kettle with a 4-5% solution by weight of citric acid/water, fill the kettle with the hottest tap water you have then turn the kettle heater on and bring the solution up to ~150°F or so then let it sit lidded overnight. Next day empty the acid and rinse thoroughly - preferably with low-ionic water (DI or RO) for the first rinse to avoid any acid/mineral deposition - after the first rinse tap water is fine.

The acid will fry out exposed iron particles at the surface which will then allow the kettle to grow a full chromium oxide layer to "coat" the kettle and hopefully preclude rust from forming in the future...

Cheers!
 
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cchristoph

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It would be sad to think a brand new kettle developing rust spots was "normal", but bottom line, it sounds like that kettle needs to be put through a(nother) passivation cycle.

Pick up enough powdered citric acid to fill your kettle with a 4-5% solution by weight of citric acid/water, fill the kettle with the hottest tap water you have then turn the kettle heater on and bring the solution up to ~150°F or so then let it sit lidded overnight. Next day empty the acid and rinse thoroughly - preferably with low-ionic water (DI or RO) for the first rinse to avoid any acid/mineral deposition - after the first rinse tap water is fine.

The acid will fry out exposed iron particles at the surface which will then allow the kettle to grow a full chromium oxide layer to "coat" the kettle and hopefully preclude rust from forming in the future...

Cheers!
Damn. Was hoping to brew tomorrow. But will do. Would rather fix it than ruin a brew day.
 

hotbeer

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304 Stainless isn't the greatest for rust resistance. Though in normal use it's more than adequate. But it's also about the cheapest and most common SS I think.

When you keep stainless in water, you might be depriving it of the O2 it needs to keep it's thin layer of protection or perhaps the water chemistry was a factor or something else causing some galvanic corrosion to occur.

On the sail boat I use to have, I learned quickly that in areas that stayed wet to use 316L stainless steel. Particularly for hose clamps. 304 SS would be rusted through in a years time. 316L wasn't phased a bit.
 
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cchristoph

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10-4. Thanks y’all. Will keep rollin for now and give her an acid bath afterwards.
 

day_trippr

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wrt marine use one absolutely wants to use 316 over any other austenitic stainless steel. The molybdenum addition and incrementally higher nickel content help 316 withstand the constant chloride exposure that would consume 304.

Fortunately, as long as one avoids using chlorine-containing products I don't think that's much of a concern for brewers...

Cheers!
 
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cchristoph

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My tap water is pretty high in chlorine. Or at least it smells like it is. Don't know about the water the OP used for the 4 day test.
Not sure either. But I know my water is super hard. Need to look up report. Definitely wouldn’t rule that out as being a possible cause of it though.
 

hotbeer

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I'd just wipe it off and brew. Though purist might be aghast, I use Brillo or SOS pads on my SS stuff. A friend tells me that it will rust because of that, but I've never had any rust on them from the steel wool pads. And it's been 30 years since I had that argument with him.

If you do clean it and scrub it really good, you can also just heat it up in the oven. Assuming it's just a kettle and not something with electronics in it. Probably 400F for 10 minutes will do it as good as any chemical bath.

Though I don't even worry about that when I clean my pot's extra well. They pretty much take care of themselves if you aren't going to do things like let them sit filled with water for days.
 

hottpeper13

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My Spike 15 gal kettle came with a packet of Bar Keepers Friend for passivation stapled to an instruction card.
 

day_trippr

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Powered BKF is good - even great - at removing surface blemishes like rust spots, but given it's abrasive and relies on oxalic acid it's not a good agent for actual passivation of stainless steel. A non-abrasive solution containing either nitric acid (major pita to use) or citric acid (easy AF to use and extremely effective) is highly preferable...

Cheers!
 
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If you are shy about using SOS or any kind of steel wool on your kettle, I am (so far) pretty impressed with these. I have seen them at Lowe's and Tractor Supply.
04946578.jpg
 

day_trippr

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Do I need to fill up the 15 gal kettle with the citric acid solution?
Ideally, sure, but if one is just trying to remove evident rust spots and ensure passivation of the affected area filling to a bit above the highest spots could be sufficient.

fwiw, citric acid is cheap on Amazon.
And using iron wool in an SS or aluminum kettle is begging for problems...

Cheers!
 
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cchristoph

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It would be sad to think a brand new kettle developing rust spots was "normal", but bottom line, it sounds like that kettle needs to be put through a(nother) passivation cycle.

Pick up enough powdered citric acid to fill your kettle with a 4-5% solution by weight of citric acid/water, fill the kettle with the hottest tap water you have then turn the kettle heater on and bring the solution up to ~150°F or so then let it sit lidded overnight. Next day empty the acid and rinse thoroughly - preferably with low-ionic water (DI or RO) for the first rinse to avoid any acid/mineral deposition - after the first rinse tap water is fine.

The acid will fry out exposed iron particles at the surface which will then allow the kettle to grow a full chromium oxide layer to "coat" the kettle and hopefully preclude rust from forming in the future...

Cheers!

Got the citric acid. Just want to make sure I'm on the right path before running this if you don't mind double checking me.

Filling to 10G with tap and heating to 150-160F
Adding in 5lb bag of citric acid (I know it's a overkill, is that ok?)
Running for one hour at 150-160F (Is it ok if I run this solution through my riptide and silicone hoses?)
Rinsing with DI
Rinsing with tap
Let it air dry
 

IslandLizard

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Adding in 5lb bag of citric acid (I know it's a overkill, is that ok?)
To fill a 15 gallon kettle, with 4% Citric Acid (by weight) you'd need 2.3 kg = 5 pounds, of Citric Acid (Anhydrous). So it's not overkill if you're doing it that way.

15 gallons = 57 liters = 57 kg (water)
57 * .04 = 2.28 kg = 5.03 pounds

However, for a single use it's a gross waste of resources.
Not sure it's worth to reclaim and store for a next use. 15 gallons takes 2.5 brew buckets.

You can stick a brew bucket filled with water inside the kettle to reduce the volume needed...
 

day_trippr

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^All good^

Once it reaches temperature I would let the acid solution sit overnight for best results.
Recirculation is an unnecessary complication, imo...

Cheers!
 
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