THE CLEANING OF STAINLESS STEEL

Always attempt the mildest cleaning method first. Be patient - repeat it a fair number of times before resorting to the more severe cleaning methods.

Routine Cleaning. Stainless Steel's best friends are quite simply soap, mild detergent or ammonia solutions in warm water, applied with a soft cloth or nylon sponge.

Occasionally the use of the least coarse nylon scouring pad may be required. Rinse and dry with a soft cloth.

Stainless steel sections are ideally suited for washing in a dishwasher. Only if cookware is heavily soiled is any prewashing required. (Note: Don't wash in dishwashers which have galvanised (Zinc Plated) components. Indelible stains can result on the surface of Stainless Steel).

Such simple Routine Cleaning will easily remove normal soiling. Repeated application will often remove heavier soiling and stains will become less noticeable and may completely disappear.

Cleaning - Moderate Soiling, Light Staining. Apply the mildest household abrasive cleaner, or a paste made from fine chalk or soda bicarb, using a soft cloth or a fine nylon scouring pad. A soft bristle brush may also be used. Rub the surface as softly as possible using long even strokes in the direction of the polished finish if this exists. Avoid using a circular rubbing action. Rinse well and wash as described under Routine Cleaning.

Cleaning - Heavy Soiling, Heavier Staining. Presoak in warm/hot detergent or ammonia solution. If this does not sufficiently soften burnt food or carbon deposits, household caustic cleaners will have to be used. Follow by cleaning as for Moderate Soiling, Light Staining. Repeat if necessary.

If this does not suffice final resort may have to be made to the use of both coarser abrasive cleaners and nylon scouring pads, but with the risk that the surface may become slightly affected. Follow by a thorough rinse and Routine Cleaning.

It is usually only the inside surfaces of cookware that are heavily soiled. If the more severe cleaning methods therefore have to be used - take care - Do not apply them to the outside surfaces where they are not required.

General Problems and Corrective Action.

· Acids
Avoid contact. If accidental contact does occur rinse immediately and soak in ammonia or soda bicarb solution. Follow by Routine Cleaning.

· Bleaches
Avoid contact with concentrated or undiluted bleach. If accidental contact does occur rinse immediately and soak in ammonia or soda bicarb solution. Follow by Routine Cleaning.

· Carbon Deposits/Burnt Food
Treat as described for Heavy Soiling, Heavier Staining

· Fats, oils and grease
Wipe off heavy deposits with a soft cloth or paper towel. Presoak in warm detergent or ammonia solution. Follow by Routine Cleaning.

· Finger Prints
Use Routine Cleaning. If necessary first treat the marks with a soft cloth or paper towel dampened with alcohol (methylated spirits), or an organic solvent (ether, benzine). Minimise the re-occurance by applying a wax based household polish to the dry, cleaned surface.

· Films
A dull, cloudy film, or a "rainbow film" develops after drip drying. These are respectively due to too much detergent, or oil/grease in the washing-up water. Re-wash as for Routine Cleaning using fresh, clean water.

· Heat Discolouration/tints
Ease of removal depends on the severity thereof. Repeated cleaning as for Moderate Soiling, Heavier Staining may prove successful. If not, use a 10% solution of Nitric Acid* together with a fairly course household abrasive cleaner applied as a paste by hard rubbing with a coarse nylon scouring pad. (Some alteration to the surface appearance will result from these severe cleaning operations). Acid treatment must be followed by rinsing in ammonia or soda bicarb solution, and Routine Cleaning.

· Labels
Peel off as much as possible. Soak well in warm water, rubbing periodically with a soft soapy cloth or sponge. If adhesive remains, dry and rub gently with alcohol or organic solvent.

Don't remove labels by scratching off with a blade, or rubbing with coarse abrasives.

· Leakage and Spillage
Remove by thorough washing down as soon as it occurs, or at short regular intervals.

· Oily Deposits in Coffee Pots/Urns
Use a thin paste of soda bicarb in hot water, and rub with a fine nylon scouring pad. Rinse and follow by Routine Cleaning.

· Rust Stains
Light, superficial brown staining can be removed by Routine Cleaning repeated regularly for a few days. Similarly, repeated cleaning as for Moderate Soiling, Light staining will remove darker stains.

Rust spots with a halo around them indicate that a fragment of ordinary steel has become embedded in the surface of the Stainless Steel. Dab and spot, keeping moist for 20 - 30 minutes, with a 10% solution of Nitric Acid* on an ear bud. Repeat this treatment until no reoccurrence of the rust spot occurs. Severe rust stains are best removed by swabbing the stain, keeping it moist for 15 - 20 minutes with a 10% solution of Nitric Acid*, repeating if necessary. Very severe stains will require hard rubbing with a paste of fine household abrasive and 10% Nitric Acid*, using a fairly coarse nylon scouring pad, Acid treatments must be followed by rinsing in ammonia or soda bicarb solution, and Routine Cleaning.

· Sterilization
Add the sterilizing solution in the strength as laid down in the instructions. Avoid overdosing or the addition of concentrated solutions in one large dosage. Do not leave the sterilizing solution in the equipment longer than necessary, especially under stagnant conditions.

· Tannin Stains
Use a thin paste of sodium carbonate (washing soda) in hot water, and rub with a fine nylon scouring pad. Rinse and follow by Routine Cleaning.

· Nitric Acid (HNO₃)
Nitric acid is a "friendly" acid towards Stainless Steel and is the only mineral acid which should be used to clean stainless steel. Avoid contact of the acid with other metals, particularly the aluminium and copper bases on cookware. A 10% solution (1 part Nitric Acid added to 9 parts water) is usually used. It may be obtained from most chemists, who will make up the 10% solution. Concentrated Nitric Acid must be handled with care. Dilute 10% solutions are less dangerous, but it is advisable to wear rubber gloves and eye protection. If accidental skin contact occurs, wash well with lots of water. Mix and keep the solution in glass containers. Dilute extensively before flushing down the drain. Keep it out of reach of children.