Page 1 of 1

Rendering galvanized metal harmless

Posted: Tue Feb 03, 2009 9:46 pm
by mgwerks
I know the drill about using galvanized steel in the presence of heat, and all the 'nasties' that it can give off. The question is this - can the galvanized coating be removed relatively easily? I suddenly have access to a decent quantity of HD galvanized expanded metal, and I could replace all my charcoal baskets and worn grilling surfaces with it. If I could torch off or burn it off in a fire so they could be utilized, it would save me a great deal of $$$.

The answers I have come up from welding forums are these:

If you heat it hot enough, you'll burn off the zinc galvanizing. It will produce a thick sweet smelling white smoke and might leave a powdery residue on the screen. It will do this every time you heat it up until all of the galvanizing is burned off. The smoke is very dangerous, so do this in a well-ventilated area. I can do this outside, and we have a perennial wind. Out in the country the fumes should dissipate and not cause any issues

You can remove the zinc coating by soaking over night in vinegar or in an hour or so using muriatic acid. A 50% solution of Muriatic acid and water will remove it. be sure to wear eye protection. Placed in diluted muriatic zinc/galvanized will almost instantly begin to react & fizz, even if it is hidden under a rusty layer. Continue bath until ALL fizzing stops, then rinse in baking soda & water to neutralize. It will start rusting very quickly after it is rinsed with clean water. If you use vinegar or acid to remove it, you can neutralize it with water and, as Rick stated, it will rust quickly. However, if you use HOT water, the water will evaporate before it flash rusts.

Comments?

Posted: Tue Feb 03, 2009 9:52 pm
by Papa Tom
Sounds reasonable to me, The only thing I can really verify is that is does give off a heavy white sweet smelling some when heated.

Posted: Tue Feb 03, 2009 10:13 pm
by JamesB
I still would be hesitant to use it... Just not worth the risk to me. My $.02

Posted: Tue Feb 03, 2009 11:03 pm
by OSD
Get a good respirator, a big fan, plenty of milk (helps if you start to feel queezy from the fumes ) and lots & lots of acetylene. On expanded metal it's going to be hard to get it burnt off all the edges and another thing to consider is how hot you will have to get the metal to burn it off. It may end up causing warping, twisting or even melting thin areas on expanded metal.
And once it's burnt off, you will have to wire brush off the white residue that's left behind from the burning. It would be a major job on that much metal.
Wouldn't be worth it to me for the time, expense (acetylene, wire wheels, oxygen ) and I could never be sure I got all the galvanizing off all those little edges of the expanded metal. JMHO

I've done small areas where I was going to weld (angle iron ) and even those are a PITA to clean.

Posted: Wed Feb 04, 2009 12:34 am
by DATsBBQ
Wiki reports

Code: Select all

The process of hot-dip galvanizing results in a metallurgical bond between zinc and steel with a series of distinct iron-zinc alloys



Depending upon how layers ("series of distinct iron-zinc alloys), you might not have much metel left. :wink:
If it were me, I pass on it.

Posted: Wed Feb 04, 2009 9:19 am
by 3 star redneck
Theres no way i would trust cooking on anything galvanized... :shock: Carbon steel expanded is only $38 for a 4x8 sheet, not a big investment to keep everyone your feeding safe from being sick.. :D

Posted: Wed Feb 04, 2009 9:28 am
by BAR "G" BBQ
I will let you draw your own conclusion from this; about 20 years ago I was doing some cutting/welding on galvanized steel one saturday. There was I thought more than adequate vinilation. On Monday I kind of went into lala land and was rushed to the hospital. The arsnic level in my body was found at near fatal levels due to galvanized poisoning. It took the better part of a year to recover, some minor damage to brain tissue was non reversible.
As Red Neck said; expanded metal is cheap.

Posted: Wed Feb 04, 2009 9:37 pm
by mgwerks
I as much thought so. Thanks for all the advice - project cancelled.

/close.

Posted: Thu Feb 05, 2009 8:28 pm
by bwsdj
good decision, your health or others isn't worth the risk. I would be paranoid that there would always be some bad stuff left