Sciencemadness Discussion Board

removing zinc from galvanized steel

rmel0124 - 12-7-2011 at 19:22

hi to all,

just wanna ask how to remove zinc from a galvanized steel manually?

bob800 - 12-7-2011 at 19:38

http://lmgtfy.com/?q=remove+zinc+from+galvinized+steel

hkparker - 12-7-2011 at 19:45

Slightly diluted HCl

rmel0124 - 12-7-2011 at 21:20

I already have a 85% phosphoric available right now would it be ok, on what concentration?

bob800 - 13-7-2011 at 07:04

I don't know, but here's what Yahoo! Answers has to say (you can find lots of info by google-ing!):
Quote:

Yes, it should. But it might form a passivating layer of zinc phosphate. Because zinc is more active than hydrogen, it will displace hydrogen ions from solution to form hydrogen gas and zinc(II) ions. We will see hydrogen bubbles and the formation of white, insoluble zinc phosphate as evidence of this reaction.

Because phosphoric acid is a weak acid, and because the zinc phosphate might protect the rest of the zinc metal from attack, the reaction is likely to be slow.

Sedit - 13-7-2011 at 18:20

Bathroom cleaners containing HCl will be more then enough to handle this if you can not get Muratic acid

Mr. Wizard - 13-7-2011 at 19:49

Sodium Hydroxide or lye solution will also work, with the added benefit of not eating into the steel, and not accelerating rusting afterwards. HCl works fast, but the rusting afterwards is very fast, even after a good rinse. I found this out while trying to remove some grease and oil from some automotive parts with boiling NaOH solution in a galvanized bucket.

I agree the Phosphoric will react with the Zinc, but you get a Parkerizing effect and a Zinc Phosphate layer does form.

bbartlog - 14-7-2011 at 05:27

I'd go with Mr Wizard. Using acid will unavoidably do some amount of damage to the steel. Sodium hydroxide avoids this.

Quote:
here's what Yahoo! Answers has to say


Try the following experiment sometime: in a field where you have expertise, look at the answers to 5-6 questions that you find on Yahoo Answers. I bet Yahoo Answers doesn't have more than half of them anywhere close to right. Seriously, people like to rag on Wikipedia (with some justification) but compared to Yahoo Answers the information in there is quite solid.

smuv - 14-7-2011 at 09:54

I wonder if you could use an aqueous solution of an iron(II) salt.

Edit: But generally for welding or preping the metal it is done non-chemically with an abrasive wire brush.

[Edited on 7-14-2011 by smuv]