CLEANING OF
STAINLESS STEEL
Stainless steels need to be cleaned for
aesthetic considerations and to preserve
corrosion resistance. Stainless steel is
protected from corroson by a thin layer of
chromium oxide. Oxygen from the
atmosphere combines with the chromium
in the stainless steel to form this passive
chromium oxide film that protects from
further corrosion. Any contamination of the
surface by dirt, or other material, hinders
this passivation process and traps corrosive
agents, reducing corrosion protection. Thus,
some form of routine cleaning is necessary
to preserve the appearance and integrity of
the surface. Stainless steels are easily
cleaned by many different methods. They
actually thrive with frequent cleaning, and,
unlike some other materials, it is impossible
to “wear out” stainless steel by excessive
cleaning. The effect of surface/pattern
roughness, grain/pattern orientation, and
designs that allow for maximum rain cleaning
(exterior applications) should be considered.
Types of surface contaminants
Dirt - Like any surface that is exposed to
the environment, stainless steel can get dirty.
Dirt and soil can consist of accumulated
dust and a variety of contaminates that
come from many sources, ranging from the
wind to everyday use. These contaminates
will vary greatly in their effect on
appearance and corrosivity and ease of
removal. While some may be easily
removed, others may require specific
cleaners for effective removal. It may be
necessary to identify the contaminate or
experiment with various cleaners.
Frequently, warm water with or without a
gentle detergent is sufficient. Next in order
are mild non-scratching abrasive powders
such as typical household cleaners. These
can be used with warm water, bristle
brushes, sponges, or clean cloths.
When water contains mineral solids,
which leave water spots, it is advisable to
wipe the surface completely with dry towels.
Fingerprints and Stains - Fingerprints and mild
stains resulting from normal use in
consumer and architectural applications are
the most common surface contaminates.
Fortunately, these usually affect only
appearance and seldom have an effect on
corrosion resistance. They are easy to
remove by a variety of simple cleaning
methods. Fingerprints are probably the
most troublesome marks to remove from the
surface of smooth polished or bright
finished stainless steel. Fortunately, they
can be removed with a glass cleaner or by
gentle rubbing with a paste of soda ash
(sodium carbonate) and water applied with
a soft rag. Once again, this should be
followed by a thorough warm water rinse.
There are several special surface finishes
where fingerprints present special problems:
polished No. 6, etched, some abrasive
blasted finishes, and light electrochemical
colors applied over satin or brushed finishes.
(NOTE: there are several special finishes
designed to withstand fingerprints:
embossed, swirl patterns, lined patterns, etc.).
Cleaning should always be followed by
rinsing in clean hot water.
We have also found that WD40 is a good cleaner
- try it in an inconspicuous spot first.
Thanks to The Stainless Steel Information Center for this information.