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Effects of muriatic acid on galvanized finish
Q. Will muriatic acid remove galvanized finish from metal? I would like to remove the galvanized finish from some old metal hinges I am trying to texture and make look old. Is there anything I can use to remove the galvanize finish?
Dan B [last name deleted for privacy by Editor]teacher/artist/blacksmith - El Paso, Texas
2005
A. muriatic acid [affil links] is hazardous to work with but should remove the galvanized finish in a flash.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005
A. Ted is right. Muriatic acid will remove the zinc just fine. Be advised that there needs to be adequate ventilation....do it outside! The gases produced will include hydrogen, so use some common sense while the hinges are stripping.
David JayeHouston, Texas
2005
Q. Thanks Ted and David,
Is there another method, a safer way, which will remove the galvanize finish? Doing blacksmithing, I know I can burn off the finish in my propane forge, with good ventilation. I prefer NOT to do this, as it uses a lot of propane and I have several hinges to work on. Also, the safety issues of burning the finish off concern me, just as they do using the muriatic acid. And how would I dispose of the acid when I'm done.
As a hobbyist, it sounds like there is no safe or easy way for me to to tackle this problem. Am I right?
Thanks for all the info guys.
teacher/artist/blacksmith - El Paso, Texas
2005
A. Finishes can, in general, be removed chemically, mechanically, or thermally. In theory the galvanizing can be sanded or blasted off of the hinges, although I don't know if all visible areas will be fully accessible to the sanding or blasting.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2005
A. You can try soaking them in a solution of 2 tablespoons of Drano [affil links] crystals in a gal of warm water. Add the Drano with great caution! Rinse under flowing water for a couple of min each and transfer to a pail of vinegar [in bulk on eBay or Amazon]. White vinegar in gal jugs is not expensive. Let set for an hour. Remove and brush the black smut off with a vegetable brush under flowing water and repeat the vinegar/rinse cycle as many times as required. Bake when thru or it will rust like mad; rubber gloves [on eBay or Amazon], apron [on eBay or Amazon] and a face shield [affil links] are mandatory.
James Watts- Navarre, Florida
2005
Q. Recently I saw an acid-wash finish done to some zinc-galvanized sheet metal that I would like to reproduce for myself. The resultant patina makes the metal look very much like old lead:
It appears that the strength of the acid wash isn't sufficient to completely remove the galvanized finish, but it is strong enough to seriously etch and affect it. I'm curious what you recommend to experiment with in order to achieve a similar finish? Thanks so much for any advice, Dave
- Fairfax, Virginia, USA
May 6, 2013
A. Time, Temperature and Concentration are the main things that control the amount of attack.
I would start with a 5% acid 95% water and see how that works.You can always add more acid and you can do it several times.
Remember it needs to be very well rinsed or a very slow attack will continue in some places.
- Navarre, Florida
May 7, 2013
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