Mini Keg Discussion / Mods / Show Off - Dedicated Thread

[Zorco]

Works on the Mac. No worries

 

[nosco]

I sometimes get rust spots on my brew kettles like the ones at the end of the vid so thats maybe not a huge concern if i can get rid of them. I would'nt know what to make of the spot near the weld or the weld itself.

Would citric acid work better as a passivator(?) than starsan?

 

[Jack of all biers]

Finally got it working. I have only used this keg a few times because a faulty reg so it has been cleaned with perc and stored with a starsan solution. Im the wrong person to be making any conclusions from this but I would have thought that the starsan would passivate the stainless. The rust spots at the end could maybe be fixed by re-passivating. Its hard to see the weld in the light but Ill have a go at it with some Tricleanium and starsan when I get the time. I hope the vid helps.
...
Edit:the camera is a usb camera from the plumbing section at Bunnings about $35. The vid is of the inside of the top of the keg.

Not sure on your welds, as they are hard to see, but where the obvious rust is are some fairly clearly defined scratch marks from machining. Cleaning with acid and re-passivation should work on these, though you will likely need to re-passivate every now and then as crevices tend to gather corrosive substances that will eventually lead to further rust over time.

EDIT - Nosco, just saw your post at #862. Citric acid is a more economical passivator than starsan (price wise) at the right concentration and temp should wash away the contaminants so that passivation can take place. There are a few commercial SS passivation solutions that use Citric acid, so you are on solid ground and it is a lot less dangerous (for you and the waste water) than nitric/fluoric acid solutions.

 

[Coldspace]

Well I thought I would add my discoveries, good for me so far...... maybe, and this is not knocking the good work from others or the bad luck from others as I may still have ticking time bombs.....

I bough 4 x 5 ltr kegs bulk buy 2. Cleaned with percarbonate soak for 1 hour then rinsed with water. I spray light starsan only if filling and leaving full for more than a few days like nows trip for easter, for bbqs over night I usually just rinse the mini with hot water then fill.

Ive used them solid last Christmas for 3 weeks. most of the time they carried beer for 1- 2 weeks. Ive used them over past several months sporadically for local social events including leaving beer fo upto 2 weeks in them, still no issues.
watching this thread has made me anxious that ive got sus ones but at this stage I'm still happy with them.
Ive kegged up some brews filled from my primary stocks for easter camp next week, these were filled to the absolute neck, under pressure till foam leaked out of the pressure valve 6 days ago. and I tested a pot of these today to make sure I wasn't dragging crap beer away, all tasted and appeared exactly the same as the ones in my primary cornies, so I'm either one of the lucky ones or I got kegs from the Monday/Tuesday welder and not Fridays one
pictured is my lovely crisp rice lager and my LC pale ale abit darker due to the crystal , I also had my 3 rd mini yesterday filled with my nelson sav lager which I took to a friends house last night which dispensed amongst a few and was great and the same as the mother keg at home and no one knew any diff.

I feel for you guys after watching things unfold and hope at the same time mine don't fail in the next few years as one would hope at least a decade of use with stainless or more...
I'm still following this like the rest of yous
I have not tried the rice rinse test on these and my 4 th keg is full with a stout and I'm taking these all away next week , so I hope mine don't fail soon otherwise Ill be pissed lol


my mini reg has been OK with adjustments but does leak the bulbs out fast which I'm sure is an internal leak. BTW it has no serial number so its prob a dud anyway..

Carry on the good works guys, not taking anything away from this thread , just adding my observations with my gear, maybe it was poor workmanship on some and not others?

Edit". My minis are slightly magnetic in the rolls and bottom and non magnetic that I can feel in the sides and are marked beer can..

Another idea, is that I got mine from bulk buy2 , but maybe mine were made at an earlier date or later than some others and all shipped at the same time????
Cheers

 

[nosco]

Maybe OT but how does TSP differ from vinegar and citric? I realise its an alkaline cleaner (it is isnt it?). My current method to passivate my SS is to use TSP and then use starsan in stead of citric. So if we are talking about removing rust with vinegar or citric how would TSP work and how would temperature affect it?

 

[peteru]

TSP is mainly a degreaser. You use it first to clean the surface before passivation with an acid based solution.

 

[Bones99]

Alrighty,

I've just knocked up a spreadsheet to track this issue, A good idea from earlier.

A five second memory dump has about 5 people which I've invited. If you have an issue with your keg regarding metal taste, darkening of your beer etc. let me know and I'll add you to the PM.

Try and fill in all the fields as it may help with tracking a bad batch.

Hi Zorco, add me into the spreadsheet too thanks

 

[Parks]

Hi Zorco, add me into the spreadsheet too thanks

Me too please mate. Mine is from the third buy I think and I get a lovely black smear when I run my finger inside the 4L one

My 2 iKegger growlers are also bad but I'll contact them directly.

 

[Jack of all biers]

So, I finished the metallic tasting keg tonight and rinsed it out with hot water only. Rubbed my fingers on the inside of the neck weld and smooth as a baby keg should be. Rubbed a bit further in and around the top cone part and pull my fingers out. First photo is with the flash, second without.



It looks like a greasy film and after washing my hands thoroughly with soap, the black has remained in the recesses of my finger prints. It didn't have an oil type odour nor feel oily, but sure did shine like oil. The beer had a bit of a sharp after taste that hung on the tip of the tongue, but mostly the only taste was iron/metallic exactly like when you cut your lip and taste blood.

This has got me stumped as the welds I can see and feel are smooth and clean. I can see some scratch marks on the base (similar to Nosco's video, but no rust). I will get a mirror small enough to get in the thing and have a better gander at the top welds, but I have the feeling mine is minor and probably needs a better clean job to get rid of reside crud from the various acid washes and bathes it would have gone through in the factory to clean it up.

 

[peteru]

I've done a trial "electropolishing" run experiment. I put electropolishing in quotes because I have no clue if I'm doing it right or if it is actually electropolishing or just a similar process with observable results, but here it goes.

The test vessel is a stainless steel cooking pot that was at one stage left on the stove and boiled dry on maximum heat. This caused a black oxide layer on the bottom of the the pot that could not be cleaned with vinegar, caustic soda, trisodium phosphate or an abrasive cleaner, such as Jif.

For my test, I used a 12V / 1.5A DC power supply (from an external Seagate HDD), with the positive terminal hooked up to the pot and the negative terminal connected to a stainless steel (I think) bolt. In order to judge the effectiveness of the process, I tilted the pot so that only half of the surface was subject to the process. I used white distilled vinegar with additional extra citric acid, heated to 70-80C, as the electrolyte. The surface was treated for about 15 minutes. To have a control, I subsequently rotated the pot 90 degrees and left it subjected to the heated electrolyte for about 20 minutes without any current being applied.

The results are encouraging. There is a visible reduction in the blackening of the pot where the "electropolishing" took place. The control segments with just the hot acid show no visible improvement.

 

[malt and barley blues]

Friend of mine who doesn't brew is after a couple of mini kegs, wanted to know how much, where to buy, directed him to AHB he is not a member and I warned him that some of the the last batch was rusty. He called me this morning and told me that there was mention of rusty kegs in the first buy, directed me to a post by Crunch, post 27 Mini Keg and Growler EOI. Sure enough he warned of rusty kegs, so rusting not just an isolated incident.

 

[nosco]

Did you use straight vinegar with the citric peteru?

 

[Zorco]

I still trying to coordinate a ss grade test

 

[peteru]

Did you use straight vinegar with the citric peteru?

Yes. It was undiluted white vinegar. Homebrand from Woolies. It comes in 2L bottles, but I only had about 50mL to hand.

 

[nosco]

So I tried a vinegar/citric acid wash tonight with no improvement on the rust.

I tried a short bristle bottle brush first but it was to bendy to get any pressure on it. Then I did a glass of vinegar with some sand and as you'd expect it didnt do shit. Then I heated up a bit over 1.5lt of vinegar (white vinegar from Aldi) with 2 big tbsp of citric and the rest of water to 5lt. I heated it up to 75c. The I even got a 12v power supply and did the same as peteru for 20 minutes. I could hear the tiny bubbles as soon as I turned it on. The stainless bolt came up really well.

The seam welds and spot welds seem to have come up really well but it looks like absolutly no affect on the rust. The 3 pics below are just after the sand. The last 4 are after the hot vinegar soak.


Edit: I did give it clean with TSP on Sunday too.

 

[peteru]

The current density (total current / area) plays an important part in how effective and quick the electropolishing will be. I suspect that a large electrode and several Amps will be required. Maybe a welding power supply?

Whatever you do, make sure you don't arc or short circuit the electrode against the keg. Not only will you damage the surface (by effectively spot welding), but you also run a risk of explosion. The electrolysis will create hydrogen and oxygen and a spark will ignite the mix and go pop/bang/boom. Combine that with hot acid and you get yourself into an ugly mess.

 

[Grott]

Besides warranty issues, would it be worth talking to a plating factory as to the pickling process and cost per keg, batch of kegs?

 

[nosco]

The power supply i had was only 500mA. Yeah nah, thats enough experimenting for me.

 

[Coalminer]

Besides warranty issues, would it be worth talking to a plating factory as to the pickling process and cost per keg, batch of kegs?

Maybe so. I was wondering the same

 

[GoodDuck]

I think not, due to the mentioned warranty issues. i.e. who becomes responsible warranty wise?