Where the
world gathers for metal finishing
Q&As since 1989


-----

Stainless steel splashed with acid

 

I own a cleaning company. I hired someone to acid-wash a quarry tile floor in a supermarket. muriatic acid [affil links] was used. Some of the acid splashed on the stainless steel. We haven't seen the condition of the stainless steel - but we need to "fix it". Any suggestions?

Barb Schimanski

---

 

Muriatic acid is a trade name for hydrochloric acid, HCl. HCl will attack iron and stainless, so your best bet would be to remove the steel to a safe location prior to application. Immediate rinsing or even immediate neutralization with baking soda [on eBay or Amazon] followed by a rinse might lessen the damage. If damage has been done, there will probably be no way to "fix" the parts; replacement may be necessary. If the damage is superficial and not structural, mechanical finishing can remove the discolored surfaces.

Phosphoric acid is a bit less aggressive toward stainless, and phosphoric acid followed by a rinse and then a sodium hypochlorite bath [adv: bleach/sodium hypochlorite in bulk on eBay or Amazon] (plus a rinse) is often used to etch and bleach grout. hydrogen peroxide 3%) [affil links] can be used as well, but test the oxidizers on a small area first, as these oxidizing agents can alter pigments in some unglazed tiles.

Dale Woika

---

 

Barb:

Get yourself some citric based cleaner and a variety of Scotch Brite pads and go to work on the stainless. You can match the existing finishes by varying the pads and pressure and direction of hand polishing. It is hard work, but you should be able to "save" the SS that was splashed with acid.

Dan Weaver