burn on inside of stainless steel brewing kettle

[Ace_Club]

Ace, from what I understand, stainless is an alloy, not a coating. It's not Teflon. Yes, you can scratch it off, but it's stainless underneath.

Yes, I understand the metallurgy of stainless steel, I'm talking about scratching the passive film.

"The chromium in the steel combines with oxygen in the atmosphere to form a thin, invisible layer of chrome-containing oxide, called the passive film. If the metal is cut or scratched and the passive film is disrupted, more oxide will quickly form and recover the exposed surface, protecting it from oxidative corrosion. The passive film requires oxygen to self-repair, so stainless steels have poor corrosion resistance in low-oxygen and poor circulation environments."

 

[dmfa200]

I work with someone with the same story. He worked at Coors and told me EVERYTHING was SS, even the drain/sewage system. He also taught me how to TIG and stick.

Sounds like a hardcore job. How thick was this SS pipe? I'm assuming you used an angle grinder. What size? What brand of brush?

The stainless pipe I've welded varied in thickness from .035" to .5"
1/2" diameter up to 24" in diameter.
Yes, angle grinders were used. 4 1/2" and 7" grinders were used.
We used grinders to prep the bevel.
Most often a wafer disk or cut-off disk to feather the tacks, and starts and stops. We used an ordinary stainless steel wooden handled wire brush to remove weld discoloration after capping the weld when complete.
A wire wheel on a grinder will rough up the surface, so using them is not a good idea.
After all welding was complete X-rays were taken of random welds or 100% depending on the type of service, by the inspector.
Then the piping was hydro-statically tested to 1 1/2 times the service pressure. So if the pipe was to be under 900psi of service pressure it was pressurized to 1350psi and held at that pressure for the period of an hour with no allowable pressure drop.
After hydro testing the pipe was installed. NOOOOO repassivation!
Again, strict adherence to procedure was followed.
Codes I've followed while welding were ASME B31.1 and B31.3, API 1104, ASME BPVC, and AWS D1.1


Stainless steel is very resilient, very forgiving, and an amazing metal if you know how to work with it.

 

[wilserbrewer]

Back to the OP... a little dishwasher detergent, hot water and a long soak will remove most organics.

 

[Ace_Club]

Codes I've followed while welding were ASME B31.1 and B31.3, API 1104, ASME BPVC, and AWS D1.1

Stainless steel is very resilient, very forgiving, and an amazing metal if you know how to work with it.

Again, I'll trust my information to come from professional brewers (Ashton Lewis) and people with metallurgy degrees (John Palmer). Not someone with experience meeting codes that have nothing to do with brewing or sanitary welds. (Also I'll assume you meant AWS D1.6 (Structural Welding Code - Stainless Steel) as D1.1 doesn't apply to stainless steel)

 

[tomroeder]

I had a similar problem, and I dumped out my used starsan in there and let the acid eat it off. Left it in there for a few days and it wiped right off! Simple!

 

[Ace_Club]

And some more cleaning tips, this time from the makers of Stout Tanks & Kettles:

"Here are some tips for taking care of your Stout Conical Fermenters, Brew Kettles, and the like.

1. Never use steel wool, stainless steel wool, Brill-O Pads, etc. Use a sponge or at the most a blue "scrubby." Avoid green scrubbies from 3M as they will scratch the mirror polished finish.
2. After each use, disassemble the valves (it is very easy to do) and clean the parts. Beer and other liquids can get trapped inside the body and ruin your next batch of beer. This is why we made the valves so easy to disassemble – if it is hard – or even a minor pain to do - many people won't do it.
3. Never use bleach as a sanitizer. It corrodes stainless steel.
4. Use a bottle brush or test tube brush to clean out the inside of the side outlet port."

 

[EarthBound]

Back to the OP... a little dishwasher detergent, hot water and a long soak will remove most organics.

This is true, but have you tried it with a bunch of burnt-on black crap? I did. It didn't phase it. Even a 30-minute (I wouldn't go longer than that because of pitting) soak in OxiClean will not phase it. BKF/elbowgrease may work for fairly small amounts (like the 3 inch spot the OP mentioned), but I doubt it will work for most cases of burnt-on black crap.

A Google search on this subject will yield some fairly interesting results. From what I've found, ammonia is the best procedure. I look forward to posting the pics of the results because this thread could really use some pics...

 

[Catt22]

I've soaked stainless in a hot Oxyclean solution for long durations with absolutely no problems at all. No pitting or any other issue. I think that the reports of Oxyclean reacting with SS are mucho bravo sierra. Either that, or the pilot had mistaken aluminum for SS. I've filled corny kegs with hot Oxyclean solution and left them for days on end with zero issues.

 

[Randar]

Seriously? OxiClean is heavily used by many people on this board to clean their stainless and other brewing equipment. It is chemically the same as PBW (with some added fragrance if you don't buy the OxiClean Free). You need to do some research.

IIRC, OxiClean is a less concentrated version of PBW but without the TSP (or current equivalent) additive, which is 30% of PBW by weight, so not totally identical. But I do use the OxiFree in my CIP/cleaning process with no issues.

I don't see the need to routinely "scrub" my kettles, so a gentle detergent is all I need generally. That being said, I currently have quite a bit of scale so I need to do a quick oxyclean and Bar Keeper's Friend cleaning.


As for the issues with passivation, use some BKF or other stainless cookware cleaner/polisher and you will be able to easily repassivate any of your kettles or brewpots (you should also treat any new drilled hole in a SS pot with BKF or other re-passivating cleaner). BKF or the stainless cookware cleaner (generally has tiny metallic flakes in it as a bit of an abrasive) but it is is great for scorched or baked-on-crap on cookware.


Personally, I wouldn't use the abrasives or anything that MAY mar the surface in any way on the inside of a fermentor (I have a stout tank and sankes as my primary fermentors), but kettles are a different animal, IMO.

 

[Randar]

I've soaked stainless in a hot Oxyclean solution for long durations with absolutely no problems at all. No pitting or any other issue. I think that the reports of Oxyclean reacting with SS are mucho bravo sierra. Either that, or the pilot had mistaken aluminum for SS. I've filled corny kegs with hot Oxyclean solution and left them for days on end with zero issues.

Tend to agree with this. Either extremely high concentrations of OxiClean were used or the reports are based on confusing aluminum with SS. I have never had an issue with pitting on any SS vessel and I have also left for a couple days. This also includes a SS slop sink that has held a tub of oxiclean for a week on a couple of occasions.

 

[Catt22]

Tend to agree with this. Either extremely high concentrations of OxiClean were used or the reports are based on confusing aluminum with SS. I have never had an issue with pitting on any SS vessel and I have also left for a couple days. This also includes a SS slop sink that has held a tub of oxiclean for a week on a couple of occasions.

FYI, I've applied Oxyclean to stainless at near full strength using only enough hot water to wet it to a paste consistency. Same result with zero pitting or any other discernible damage to the metal. The only commonly used chemical that I have seen attack stainless is chlorine bleach. That stuff will definitely pit stainless. Long ago, I managed to completely ruin a stainless steel stove top wiping it down with bleach. That won't happen again!

 

[Ace_Club]

i think that the reports of oxyclean reacting with ss are mucho bravo sierra.

+1

 

[EarthBound]

Sweet. It's actually a relief for me to dismiss any notions of pitting from using OxiClean.

I'll try an OxiClean soak and an ammonia soak. I'll post the comparison results.

 

[nutty_gnome]

Its "a lot of bullshi!t" And it is. Oxyclean free and a stainless boil kettle are a match made in heaven.

 

[Catt22]

I'm interested in the results of the ammonia soak. I have not tried that yet, but ammonia works wonders for cleaning bottles and leaves zero residue no matter what. I know Oxyclean also works on bottles, but sometimes it can leave a chalky film under certain conditions. The film is easily removed by a quick rinse with dilute StarSan or white vinegar, so it's not really much of a problem at all.

 

[Catt22]

Its "a lot of bullshi!t" And it is. Oxyclean free and a stainless boil kettle are a match made in heaven.

IMO, Oxyclean free, or otherwise obtained, was one of the best discoveries for home brewing use. RIP Billy Mays!

 

[EarthBound]

I'm interested in the results of the ammonia soak. I have not tried that yet, but ammonia works wonders for cleaning bottles and leaves zero residue no matter what. I know Oxyclean also works on bottles, but sometimes it can leave a chalky film under certain conditions. The film is easily removed by a quick rinse with dilute StarSan or white vinegar, so it's not really much of a problem at all.

The burnt-on stuff was barely affected by a 48-hour ammonia soak. The spot went from an 8" diameter to a 7.75" diameter. I should've taken pics. It's been soaking in oxiclean since last night. I'll make sure to take pics tonight. A 24-hour soak should be sufficient, don't you think?

 

[tomroeder]

Use some spent star-san. It is acidic and will usually eat up burnt on stuff.

 

[Golddiggie]

I've been able to clean anything that got burned onto my stainless steel pots using a hot water soak (as hot as you can get, and let it sit) or boiling water in the pot for a while (depending on how bad it is, a 20 minute boil should help out) and then using some BKF (Bar Keepers Friend) with a scrubbing sponge. I have yet to come across ANY burn (on SS) that can resist the combination. With BKF, typically, you only need to use it once, or twice, on a burn in order to get it clean. Obviously, rinsing between times, and using enough BKF to do the job. Wet scrubbing sponge, wet pot, sprinkle in enough BKF and go to town... If you have any muscles at all, it will get clean faster than you probably think it will.

 

[Chefkeith]

Seriously? OxiClean is heavily used by many people on this board to clean their stainless and other brewing equipment. It is chemically the same as PBW (with some added fragrance if you don't buy the OxiClean Free). You need to do some research.

So, I did some research, and they don't, in fact, appear to be chemically identical. It seems that PBW contains metasilicates, and OxiClean does not.

To be fair, though, Charlie from Five Star (PBW) was pretty ambiguous when he prepared the MSDS, so maybe I'm missing something. Do you know if the actual ingredients to PBW have been published? I'm guessing Charlie is protecting his trade secrets, while the OxiClean, like most other MSDSs, is much more thorough.

Edit: I'm not taking sides in the argument, just wanted to clarify that PBW and OxiClean are not the same thing.

 

[Catt22]

Edit: I'm not taking sides in the argument, just wanted to clarify that PBW and OxiClean are not the same thing.

The two products are not identical. IMO, PBW is somewhat more potent and also considerably more expensive. The cost of PBW is a deal killer for me. Between Oxyclean and BKF, I'm pretty well covered.

 

[Golddiggie]

The two products are not identical. IMO, PBW is somewhat more potent and also considerably more expensive. The cost of PBW is a deal killer for me. Between Oxyclean and BKF, I'm pretty well covered.

Way I see it, if BKF and oxyclean are not removing the stain, then just get a 1 pound container of PBW and use it when the others fall short. For $8, it's cheap enough to not matter... Unless you pinch pennies until they sh*t dimes...

 

[EarthBound]

After soaking in oxiclean for over 24 hours, I was barely able to get anything off. Turns out that it was mucho bravo sierra or whatever. However, it still wasn’t good enough. It was better than the ammonia though! I tried BKF before the ammonia soak, and it helped because it’s abrasive, but it required too much elbow grease and would still not do the job. Maybe soaking it longer or soaking it in PBW or Starsan would help, but I doubt it will do more than the oxiclean.

I assume that boiling is more likely to do the trick. First, I will try boiling water. If that doesn’t work, I will try boiling in vinegar as mrk305 suggested. Sounds crazy, but I might as well try it, right? I don’t know what else to try after that, so I’m taking suggestions.

I bought a SS wire brush for my angle grinder, and I know it will work. Regardless of all the whining, I know the keggle will be just fine.


This thread finally has a pic. It’s the keggle I’m workin on. It definitely looked worse before the BKF, ammonia, and oxiclean.

 

[Catt22]

Did you try the oven cleaner? The heavy duty Easy Off should work, although it may require multiple application and it works best on a hot surface. IIRC, lye is the active ingredient which is a serious caustic chemical. Boiling some PBW or automatic dishwasher detergent might also be worth a try. It looks like you only have a little further to go.

 

[mariojr]

Come on over to the dark side and get a stainless Chor Boy and just scrub it off already. You know you want too It's not like your cleaning bird poop off the the hood of your DeLorean. It's just a keggle.

Funny how we'll use all kinds of chemicals to clean something that a little elbow grease will take right off.

 

[EarthBound]

Come on over to the dark side and get a stainless Chor Boy and just scrub it off already. You know you want too It's not like your cleaning bird poop off the the hood of your DeLorean. It's just a keggle.

Funny how we'll use all kinds of chemicals to clean something that a little elbow grease will take right off.

Lol... I already got the SS wire brush for my angle grinder, so I'll use that instead of a scrubber. It is funny, but it's better to work smart, not hard. Also, I just like to experiment. If I didn't want to experiment, I would've used the SS wire brush right off the bat and not wasted my time. It would've been done in a couple minutes. However, I could only find speculation on this topic, so I figured it was time to dick around with some chemicals and document the results. I'll be done experimenting tonight, and I'll post the results soon after.

 

[CoolHandLuke]

+1 for the oven cleaner. Organics need caustic, not acid.

I read some dolty advice on this thread from a most excellent and respectable member recommending a combination of an acid and caustic. Sure, if all you want is a nice reaction and salt water...

Maybe some white vinegar and baking soda. Put them in the pot let them soak a little then boil it for 10 min. See how that works.

 

[Ace_Club]

IIRC, OxiClean is a less concentrated version of PBW but without the TSP (or current equivalent) additive, which is 30% of PBW by weight, so not totally identical.

So, I did some research, and they don't, in fact, appear to be chemically identical. \

Yes, that was already covered. The main cleaning agent in both is sodium percarbonate and sodium carbonate. Next time I'll be less general in my wording.

+1 for the oven cleaner. Organics need caustic, not acid.

To that end, you could also just use straight lye (NaOH), just be sure to protect your skin.

 

[EarthBound]

+1 for the oven cleaner. Organics need caustic, not acid.

I read some dolt on this thread recommended using a combination of an acid and caustic. Sure, if all you want is a nice reaction and salt water...

I will try the oven cleaner, maybe even lye. I understand you think Steelers77's advice was fallible, but calling him a dolt is inexcusable. Many people on HBT have a lot of respect for him, so you might want to try having some, as well.

 

[CoolHandLuke]

I will try the oven cleaner, maybe even lye. I understand you think Steelers77's advice was fallible, but calling him a dolt is inexcusable. Many people on HBT have a lot of respect for him, so you might want to try having some, as well.

NaOH is generally the main ingredient in oven cleaner. Use eye protection and have a bottle of vinegar near in case of accident.