Stubborn stain in secondhand keg

[Mr. No-Tip]

I recently bought a second hand keg and sat on it for a couple months before getting my act together with a new seal kit. It had a gradient stain on the bottom that looked to me like it was caused by the soda (or whatever was in there) slowly evaporating over this time (or however long it was sitting with its previous owner)

I gave it a good soak in 2.5tsp/l PBW for about 12 hours yesterday, but the stain remains:



Doesn't actually bother me visually, but I want to make sure there's no chance of it effecting the beer.

Anyone had/have stains like this in their keg post PBW?

 

[Ducatiboy stu]

I would say its there for life. I woudnt worry about

 

[Online Brewing Supplies]

Try some dilute acid

 

[bruce86]

just got some phosphoric from the green shed. It is Chemtech's Blitz Aluminium Cleaner for ali and stainless.
Should do the trick. cost 15 bucks for a liter if that no good try your closest marine shop for the same stuff.

 

[Bribie G]

I had a couple of kegs where the old soft drink syrup or something had pooled and hardened in the tip tube "dimple" and it was almost like it was baked on.

I took out the dip tube and dropped a stanless steel wool ball in - the sort you use for scrubbing pans - then a broomstick, pushed down and twirled it like a PNG highlander making a fire with a stick and a log.

Worked great and as both are stainless you shouldn't get scratching, just a smooth clean finish.

 

[spog]

use 1/4 teaspoon of citric acid in 2 litres of hot water and leave to soak over night.
or the juice of a lemon in same water (not lemon juice concentrate ).
the citric acid also works with cleaning elements in the kettle.fill with water to cover the elements,heat ,add citric acid,stir well when it cools heat up again and leave o,night.
this will loosen the ***** stuck to the elements and make it easier to remove. cheers...spog....

 

[Mr. No-Tip]

Thanks all. I had both lemon and steel wool so gave that a go. Didn't do a perfect job, but a noticeable one. Thanks.

 

[dr K]

Acid man....
seriously ,PBW is about the best general purpose cleaner around for brewers (home or commercial) but is alkaline.
What will work really well is to pour a bit of hydrochloric acid or sulphuric acid in, let it sit for a minute or four then pour some Sodium hydroxide not straight or you may have an even bigger problem but say a 70% solution .. beware this is going to get crazy, so keep your face protected or not away. then walk away. Rinse thoroughly..

K

 

[Yob]

Wouldnt starsan overnight do the same job and a bazillion times safer? Does wonders on my copper

 

[DUANNE]

but wheres the kaboom, theres supposed to be an earth shattering kaboom.

 

[Edak]

I would use bar keepers friend (oxalic acid), gets everything out almost too easily.

 

[pk.sax]

Another plug for oxalic acid. I think that is what is in that stainless cleaner powder sold in Kmart. Anywho, but of that, a wet scorch brite, gloves and job done in a jiffy.

Or stick some acid and then neutralise with caustic like K said.