[blues450]

I seem to recall a tech tip (was it you Bill?) for using milk stone remover (MSR) from the dairy service industry for the purpose of reducing iron oxide (good old rust). I would suspect that this would be some form or concentration of phosphoric acid?

Am I barking up the wrong tree or can you and or others enlighten me further. I've got 4 badly rusted tanks to do this winter and my results with electrolysis have been spotty with a couple of electrode contact with tank disasters. I'm also thinking of trying POR 15 instead of KREEM as a lining coating. Opinions appreciated. Best, Blue

 

[Bird76Mojo]

I believe a lot of people are happier with the results when using Redkote sealer. It seems to be a better solution to this problem, and I've read about people having better results than using POR15 or Kreem.

GB :mrgreen:

 

[tbpmusic]

MSR is about 70% phosphoric acid, with an orange dye.
Mix it 50% with water, fill the tank, come back later.
It will save even the worse tanks. It's hell on rust, won't touch chrome. It will mess up paint if left long enough.
Some tanks will get de-funkified in a few hours, some may take much longer - days or even a week or more, if they're really nasty.

It is also way less dangerous than muriatic (hydrochloric) or sulfuric - if you get some on you, at least you have a chance to make it inside and rinse it off before it burns the livin' snot out of you. No noxious fumes either.
I'm a degreed chemist, I've seen what acids can do, so I stay with MSR, it's much safer.

I myself have had unsatisfactory results with electrolysis - it's strictly "line of sight", meaning that if the sacrificial electrode can't "see" the area, nothing will happen there.
That means that convoluted volumes or parts (like tanks) will yield indifferent results. Works better on flat pieces.
I keep a big 60- quart cooler full of MSR solution, I process nearly everything with it.
Some people claim it leaves some sort of protective coating that prevents further rust - I have not found that to be the case at all. In my experience you can see the rust re-forming before your very eyes. So you need to quickly either paint the piece, spray with WD40 or light oil, or in the case of a tank fill and use quickly or swish around some heavy 2-stroke mixture to coat it while you prepare to do something else with it.

Everyone has a favorite tank "sealer" - I prefer Red-Kote myself, use what you prefer.
Although Red-Kote has changed recently, it's now blue, but the same stuff.
If you go with Red-Kote, mix it down a bit with acetone to make it easier to use. The stuff is really viscous out of the can.

 

[Brown Bomber]

MSR

What does MSR stand for, and where would you fin it?

 

[tbpmusic]

Re: MSR

MSR is Milk Stone Remover - it's a dairy cleaning product, actually.
It's about 70% phoshporic acid, with orange dye. Use it on anything with rust.
I get it at Tractor Supply Store or Farm and Fleet.

 

[Brown Bomber]

Re: MSR

Thanks,
I'll check it out.
Allen

 

[woody1981]

I merged these two MSR topics into one.

- Woody

 

[blues450]

Thanks Bill.....I'm an old inorganic chemist myself and obviously share the reservations you mention re using acids. Appreciate the confirmation as "phosphoric", concentrations and dwell time info. I dare use that around the house. As well the tips re Red Kote. I'll go that way too. My Kreem jobs, though numerous, have been tedious and poor. Best, Blue

 

[donny662]

Is it necessary to line the tank after removing the rust?

 

[tbpmusic]

Is it necessary to line the tank after removing the rust?

Some guys leave it raw steel - I usually treat it with Red-Kote.