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Acid Corrosion of SS
Q. I looked at an office in west Texas for my firm. The office had corrosion (generally an orange/brown/reddish surface color and pitting) on stainless steel (alloy not known) including cabinet hinges, switch plates (common light switches/duplex outlets), sinks/faucets, and paper towel holders. Additionally, plated brass fixtures were pitted and rendered dull. Electronics (PC's and servers) and telephones (telephone switches and trunk lines) had a very high failure rate.
The office concrete floor had been recently stripped (sanded) of mastic (tile floor) and then etched with 31% hydrochloric acid (commercial muriatic acid [affil links] ) in preparation for epoxy coating adherence. The etching was done in the fully equipped office.
Can anyone direct me to literature concerning corrosion of SS, PC components, and telephone exchanges as a result of either alkaline airborne particulates from sanding of mastic off concrete floors and/or corrosion from muriatic acid "fumes" generated from full-strength commercial muriatic acid?
Stevan W. Pierceconsulting group - Dallas, Texas
2000
A. Without any shadow of a doubt, it is the uses of full strength HCl that caused the problem. I have seen it happen in two locations. People use full strength because they are in a rush. It reacts with the lime in the concrete and liberates chlorine gas/mist. this reacts with the moisture in the air to form HCl, a wonderfully corrosive material, dispersed in a very fine form that gets to everything. Worst near the floor and near exhaust ducts or doors. Most of it will have to be replaced. The better option would have been to use 10 - 25% HCl in a water solution--Not a % concentration of the Theoretical acid.
James Watts- Navarre, Florida
2000
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