muriatic acid and stainless steel don't mix

[northbay-reefer]

If you use muriatic acid to clean your pumps, you are doing more damage to it than you think. Most people use vinegar, but some of us like myself use muriatic acid. The stuff work great, but as soon as you put stainless into that solution, it will eat up the stainless steel very quickly. Most of the pump shafts are made of stainless steel. I had to get some of my stainless shaft replaced recently so if you are using muriatic acid, please make sure none of the stuff that you are trying to clean has stainless in it

 

[sfsuphysics]

Wow you really go at it to clean your pumps

 

[northbay-reefer]

ya I dont clean very often, but when I do ... watch out

 

[Raddogz]

Muriatic acid will do damage to rubber seals as well.

I use plain old vinegar

 

[jkreefer]

we use muratic acid in the electrical trade to eat away concrete that makes its way down conduits while pouring light pole bases. I cant imagine what it does to other stuff. Doesnt it eat away the plastic too?

 

[Gomer]

Muriatic acid is hydrochloric acid. nasty stuff but is safe on most plastics. If you want to go stronger then vinegar on pumps, you are probably safe using semi dilute phosphoric acid.

 

[Mr. Ugly]

Muriatic/hydrochloric acid is pretty good at attacking stainless steel. Even the fumes will corrode stainless.

 

[GreshamH]

We use hydrochloric acid on SS. You just need to know what your doing, IE. dilution and duration. Also there is more then one grade of SS.

 

[GreshamH]

[quote author=Raddogz link=topic=3636.msg41934#msg41934 date=1209440684]
Muriatic acid will do damage to rubber seals as well.

I use plain old vinegar
[/quote]

That's a new one on me. Over time I can see it but just a bath over a couple hours I haven't experienced that.

 

[Gomer]

I know we like to avoid phosphates, but the nice thing with phosphoric acid is that it creates a metal-phosphate coating which prevents rusting on iron compound. AFAIK the coating is water insoluble so that after treatment, you can remove all the phosphate residue.

 

[Roc]

I am a noob but wouldn't it be a BAD idea to clean your pumps with a posin, I mean even trace elements of that acid could kill everything in the tank very quickly.............

 

[sfsuphysics]

if you dumped HCl in your tank then yeah you could do some damage, however it's no more "poison" than water is a "poison", (chemists chime in if I screw something up) the only thing that makes something acidic (or basic) is it's ability to receive or give off hydrogen ions (and being as I'm not a chemist I'm sure I've been way to overly simplified, pH = hydrogen potential? *shrug*).

But as Gresham mentioned, dilution is key, you pour a bottle of HCl in your tank, your whole tank won't have HCl floating around it indefinitely melting everything it touches, in fact it'll quickly dilute with the water and your tank might drop it's pH a bit (depending upon how much you put in).

That being said, if you dilute HCl you don't have a full strength HCl around. yes it will burn you, but guess what so will limewater which is not acidic at all, it's at around 12.4 pH

 

[sfsuphysics]

Oh yeah to add to it, HCl (hydrochloric acid) is made of hydrogen and chlorine, both of which exist in our tank in great abundance

 

[GreshamH]

[quote author=Gomer link=topic=3636.msg41992#msg41992 date=1209492550]
I know we like to avoid phosphates, but the nice thing with phosphoric acid is that it creates a metal-phosphate coating which prevents rusting on iron compound. AFAIK the coating is water insoluble so that after treatment, you can remove all the phosphate residue.
[/quote]

I knew there was a reason we had both Thanks.

 

[Gomer]

Gresham. That little tidbit phosphoric acid came from the field and not in school lol. Between undergrad and graduate school, I took a brief job at a medical solutions company (making all those various IV injection solutions). The giant SS vats were often cleaned with phosphoric acid to halt any rusting/prevent

Mike, perhaps Roc was refering to me saying Phosphoric acid since we try and avoid phosphates in the tank.

And in reply to Roc, proper flushing with clean water should handle it. Plus, we test for phosphates so you could easily test the final rinse water.

 

[Gomer]

I was reading up a bit on phosphoric acid passivation. There is an alternate that may be of interest to us. Citric acid. The nice thing is, it is bio degradable, and when nuetralized with baking soda, is safe (by code) to dump down the drain :-D

 

[Mr. Ugly]

[quote author=Gomer link=topic=3636.msg42017#msg42017 date=1209501203]
Gresham. That little tidbit phosphoric acid came from the field and not in school lol.[/quote]

Check out Parkerizing:

http://en.wikipedia.org/wiki/Parkerize

Ages ago, I bead blasted and refinished a Colt Government model using the MnO2 and phosphoric acid version of the process.

That gun would out shoot Colt Gold Cups by the time I was done with it. The GC owners didn't like that though... ugly gun and all

 

[sfsuphysics]

Sweet, so we can use metal in our tanks now as long as we give them a phosphoric acid bath first??

 

[GreshamH]

I use SS with very little problems as well as Ti.

 

[northbay-reefer]

Wow, I leave you guy for a day and look what happen ?? two pages already