world gathers for metal finishing
Q&As since 1989
-----
Rust from Muriatic Acid Fumes
We recently cleaned one of our machines using a mixture of hot water and muriatic acid
[affil links]. We noticed that in our shop metals were rusting. How long will muriatic acid fumes continue to rust steel? Is there anything that can be done to neutralize this ?
Joe
Manufacturing, Electronics - Haveloc, Ontario, Canada
2007
2007
Hi Joe,
The muriatic (hydrochloric) acid vapor is long gone. Residual chloride (from the initial HCl-steel reaction) absorbs humidity and will continue corroding indefinitely. Possible fixes: wash with an alkaline detergent (TSP preferred) solution, then paint or wash with a water-soluble car wax
[on
eBay or
Amazon]
.
Caveat: If you ever want to paint or plate the material, avoid waxes containing silicones or fluorocarbons.
For future rust removal, use gelled phosphoric acid (e.g.,
naval jelly [on
eBay or
Amazon]
) per instructions. This leaves a somewhat protective phosphate film suitable for painting. tannic acid [on
eBay or
Amazon]-based rust converter [on
eBay or
Amazon]
s are weaker but require much less rinsing.
- Goleta, California
Finishing.com honored Ken for his countless carefully researched responses. He passed away May 14, 2015.
Rest in peace, Ken. Thank you for your hard work which the finishing world, and we at finishing.com, continue to benefit from.
Q, A, or Comment on THIS thread -or- Start a NEW Thread