Mini Keg Discussion / Mods / Show Off - Dedicated Thread

[Jack of all biers]

Could oxalic acid cause rust?

I doubt it, but you must have a reason for asking, so spit it out....

 

[nosco]

So I had a brilliant (stupid) idea of rinsing my 2lt keg with a heap of oxalic and hot water. I left it for about 30min and rinsed it out. It left a few dark grey marks on the top of the keg an the inside looked a bit more grey too (maybe my imagination) and it smelled metallic. So I figured I had nothing to lose so tonight I gave it another 30 min soak in hot perc and a big tea spoon of oxalic.

When I poured in the hot water it bubbled out and the liquid had a very noticeable orange tinge to it and the threads got instant rust stains as well as the cap and the area around the keg handle. After I rinsed it out again I had a quick look inside and I got a glimpse of a huge rust patch and I could see where rust had settled in the water on the bottom. So what the hell I gave it another 5 big teaspoons of oxalic and hot water which seemed to clean the rust away except for a tiny bit on the handle and Ill have to clean the cap again. So I dont know if the rust was already in there or it developed over night while drying out.?.

I just had a look inside with the camera and it looks crystal clean and the inside feels squeaky clean. Ill leave it over night again to dry and see how it goes. I should have taken pics of the rust but I baby sit the kids on week nights plus Im impatient as well.

 

[Jack of all biers]

So I had a brilliant (stupid) idea of rinsing my 2lt keg with a heap of oxalic and hot water. I left it for about 30min and rinsed it out.

This was not a stupid idea.

So I figured I had nothing to lose so tonight I gave it another 30 min soak in hot perc and a big tea spoon of oxalic.

This was probably not the best idea. Mixing Sodium Percarbonate (alkaline) and Oxalic (acid) won't necessarily F things up, but it sure as hell reduces the effect of both. What made you think this was a good idea? Sodium Percarbonate will clean up organic matter, NOT rust or corrosion. It is an OXIDIZER not a de-oxidizer. Corrosion or rust is the oxidation of the metal.

I would treat the keg again with Oxalic solution at 60-70C at the recommended solution and do your best to scrub the areas that have further oxidised. Then rinse with soft water (or DI water) then dry thoroughly (hair drier is good for this), then leave for a day before checking for black areas or rust. IF there are further signs of corosion, treat again with Oxalic solution and scrubing (the best you can as i know how difficult these kegs are to get into) and repeat the rinse, dry and wait period.

EDIT - and by scrub, I mean a non metallic scrub, or at least don't use iron, steel or stainless steel to scrub your keg. A green scrubby pad or other non metallic brush or similar will be best.

 

[nosco]

So the O2 in the perc probably created a heap of rust from whatever the oxaloc was taking of?

 

[nosco]

Ill get some scrubbys and repeat tomorrow nigjt minus the perc.

 

[Lionman]

I baby sit the kids on week nights.

You mean your on parenting duties? You can't babysit your own kids unless your talking about kids that aren't yours.

Sorry for the OT. Lol

 

[nosco]

Yep parenting duties

 

[peteru]

Every article I read about proper passivation technique explicitly says that after you finish passivation you must rinse and then neutralise the acid to prevent unwanted corrosion. The recommended chemical for the neutralisation is sodium hydroxide aka caustic soda. You must rinse that off too.

So the steps are:

1. Clean with 70C caustic soda (possibly save this for acid neutralisation later)
2. Rinse with plenty of water
3. Passivate with 70C acid for around 30 minutes
4. Rinse with plenty of water
5. Neutralise with 70C caustic soda for 30 minutes
6. Rinse with plenty of water
7. Dry
8. Leave exposed to air for a few days

Make sure you don't mix caustic soda with the acid, unless you want dangerous, bad juju.

 

[Jack of all biers]

Every article I read about proper passivation technique explicitly says that after you finish passivation you must rinse and then neutralise the acid to prevent unwanted corrosion. The recommended chemical for the neutralisation is sodium hydroxide aka caustic soda. You must rinse that off too.

Which acids though? Proper passivation with Nitric Acid yeah, but I don't think Oxalic or Citric will need neutralisation to prevent them corroding SS. A good thorough hot rinse with low mineral water will be fine for those acids.

 

[peteru]

I've seen neutralisation recommended for passivation using nitric, phosphoric and citric acids in particular. I don't actually recall oxalic (or acetic) acid being recommended for passivation.

At the end of the day, if the acid is capable of removing iron and it's oxides, then neutralising it when the goal is accomplished makes sense, regardless of which particular acid it was.

I think the theory is that with simple rinsing the acid can remain in crevices at high enough concentration to cause corrosion. Chemical neutralisation will work better - as long as you are not introducing anything (such as chlorine) that would promote corrosion.

 

[Zorco]

Well, it has been six months since the concept of this BB was born, and my set has finally arrived. Ohhhh boy I gleefully remember back to the original joy that these bad boys have brought many of us.

[Yob started MK BB.....................................................................................................................................................................................]

This time I wanted the 4 litre units and they are magnificent. Once I had thought that they would not have the low centre of gravity necessary to be a reliable pourer that the 5L and 2L were sure to be. The aspect ratio was not what I thought it should be...

But I was dead the frig wrong as wrong as wrong. (Thank you pints 4 and 5 for that extra "wrong" back there)

The keg holds up strong, looks bloody enchanting on the table and here is the best bit.

Perlick Flow Control........

Occasionally some shit happens to you that you can't go back from.....

A king bed, two monitors, sex with two women at once.... Life changing events... And I will tell you that Perlick flow control taps are firmly in this category.. Especially for mini kegs.

Whatever $40-50 you think isn't worth it for these..... just somehow make it happen.... Sell your cat, sell your wife. Get the Flow Control. Wait the extra 3-4 weeks and save that extra few buck.... quit smoking......don't go to the pub that month...... save that coin. Get the flow control Perlick taps.....

Now.... where is my cult thermometer order.... NO! It isn't at that level..... Get the Flow Controls.


(Lights hypocritical virtual ciggy after the climax......)

And my welds are mint... Freaking mint. No colour, perfect lines and the handle section seam has been welded directly inline with the body weld seam.

Get your weird ass stupid kegs replaced. I'm certain that Beerkat and ATHB have been the unlucky pallbearers for some stock. But the quality will eventually rise with the cream that is out there.


Mini Kegs at 8:00 o'clock...... Make it so!

Zorco.

 

[nosco]

Whats a cult thermometer? I want one!

 

[brianman]

So what's everyone using for oxalic acid, Diggers rust/stain remover?, is there anything cheaper, & how many times can you reuse. As i have a lot of kegs, wondering if i filled 4 then transfer and so on, and keep them warm in the oven. Am thinking that would be ok as mine don't have black gunk.

 

[Zorco]

Why all do this.

Why go into this

Let it be girls....... stop fiddling....


If you have a genuine product warranty claim.... Call the dude.


This thread has gone tropic. Chilllllllaxxxxxxx Yaaaaalllll. If said keg is fucked. Then contact said supplier about said fucked keg to get said fucked keg ******* actioned.


Now.....

Where is my crazy acid pokemon so I can cheerfully play with acids uselessly.



Zorco,

That Krunt

 

[peteru]

For me the best upgrade to the 5L minikeg was the Flow Control Intertap with the Keg King 90 degree stainless steel disconnect. Neat, good looking and very usable, even when the regulator is playing up.

The Intertap FC was definitely the right choice for me, I can use the stout nozzle from my main kegerator with the tap when needed.

 

[brianman]

Well, it has been six months since the concept of this BB was born, and my set has finally arrived. Ohhhh boy I gleefully remember back to the original joy that these bad boys have brought many of us.

[Yob started MK BB.....................................................................................................................................................................................]

This time I wanted the 4 litre units and they are magnificent. Once I had thought that they would not have the low centre of gravity necessary to be a reliable pourer that the 5L and 2L were sure to be. The aspect ratio was not what I thought it should be...

But I was dead the frig wrong as wrong as wrong. (Thank you pints 4 and 5 for that extra "wrong" back there)

The keg holds up strong, looks bloody enchanting on the table and here is the best bit.

Perlick Flow Control........

Occasionally some shit happens to you that you can't go back from.....

A king bed, two monitors, sex with two women at once.... Life changing events... And I will tell you that Perlick flow control taps are firmly in this category.. Especially for mini kegs.

Whatever $40-50 you think isn't worth it for these..... just somehow make it happen.... Sell your cat, sell your wife. Get the Flow Control. Wait the extra 3-4 weeks and save that extra few buck.... quit smoking......don't go to the pub that month...... save that coin. Get the flow control Perlick taps.....

Now.... where is my cult thermometer order.... NO! It isn't at that level..... Get the Flow Controls.


(Lights hypocritical virtual ciggy after the climax......)

And my welds are mint... Freaking mint. No colour, perfect lines and the handle section seam has been welded directly inline with the body weld seam.

Get your weird ass stupid kegs replaced. I'm certain that Beerkat and ATHB have been the unlucky pallbearers for some stock. But the quality will eventually rise with the cream that is out there.


Mini Kegs at 8:00 o'clock...... Make it so!

Zorco.

Yeah they're great Zorco, run mine full open @ about 4-5psi, if pressure seems too high or cracking a keg start off lower.

 

[brianman]

Why all do this.

Why go into this

Let it be girls....... stop fiddling....


If you have a genuine product warranty claim.... Call the dude.


This thread has gone tropic. Chilllllllaxxxxxxx Yaaaaalllll. If said keg is fucked. Then contact said supplier about said fucked keg to get said fucked keg ******* actioned.


Now.....

Where is my crazy acid pokemon so I can cheerfully play with acids uselessly.



Zorco,

That Krunt

Lets see what you think in a few weeks time.

 

[peteru]

More or less what Zorco said. If you can be bothered with an attempt at DIY remedy, do not use any chemical that's stronger than what you can get from Coles/Woolworths. That pretty much translates to 10% by weight citric acid in water.

Depending on how much stuff the acid dissolves, it may be single use only. If you use contaminated solution you can cause "flash attack", which ruins the surface and actually puts a black coating on the stainless steel.

Just randomly throwing chemicals at the keg, without understanding at least some of the processes and risks, is only going to make things worse.

 

[Zorco]

Lets see what you think in a few weeks time.

I know what I think now...

Everyone who bought a minikeg should have an excellent, corrosion free, balls out, tit flashing, premium mini keg experience.


We, all and everyone, should be loving this kit.

And I think we should, hopefully everyone with problems calls their retailer and gets sorted.... I know they want the same.


Schlongdog.

 

[brianman]

More or less what Zorco said. If you can be bothered with an attempt at DIY remedy, do not use any chemical that's stronger than what you can get from Coles/Woolworths. That pretty much translates to 10% by weight citric acid in water.

Depending on how much stuff the acid dissolves, it may be single use only. If you use contaminated solution you can cause "flash attack", which ruins the surface and actually puts a black coating on the stainless steel.

Just randomly throwing chemicals at the keg, without understanding at least some of the processes and risks, is only going to make things worse.

(Just randomly throwing chemicals at the keg, without understanding at least some of the processes and risks, is only going to make things worse.)
I understand that, i have done some research, am going to use 10% by weight, am going to keep at 65-70deg for 30 min.
I am waiting for one replacement keg, because of faulty/bad base seam that leaked. I will then return mine in that packaging, but am not paying for 18 returns.