Mild Acid Cleaner

Acid cleaners can be used to remove tarnish, alkaline discoloration and corrosion from metals; remove hard water deposits from many surfaces; will neutralize alkalis; may have bleaching effects.

Caution: Acids can injure eyes, skin, and fabrics; stronger acids are highly toxic and can eat through metal. Acids can etch surfaces and porcelain enamel.

Mild Acid Cleaners include Lemon Juice (or Citric Acid) and Vinegar (or Acetic Acid). They help dissolve hard water deposits from shower doors, mild rust stains and soap film and remove tarnish from brass and copper. Acids tend to bleach some stains.
Mild Acid Cleaners - Cream of Tartar (or Tartaric Acid) For example if you simmer a solution (1 tablespoons of cream of Tartar in a quart of water and discolorization of aluminum pans, caused by alkalai such as tomato sauce, will tend to dissapppear.
Strong Acid Cleaners - Oxalic Acid. Used in commercial rust removers to remove iron rust; a weak solution will remove rust stains from tubs and sinks.

Caution: These acids are highly toxic; follow label instructions exactly. Do not get on skin or in eyes, or on other materials

Strong Acid Cleaners - dilute hydrochloric acid, dilute sulfuric acid, muriatic acid and sodium bisulfate. These acids are used in some toilet bowl cleaners and etching compounds. They remove hard water and iron deposits and organic matter.

Caution: Never mix with any other cleaner! Very toxic! Follow label instructions exactly. Do not get on skin, in eyes, or on other materials.

Alkali cleaners remove and suspend heavy soil and grease so it can be rinsed away.

Caution: Alkalis can damage skin and fabrics, corrode and darken aluminum. Most (except baking soda) are toxic if swallowed.

Mild Alkali Cleaners Baking Soda (Sodium bicarbonate)

Soak burnt food from pans in solution of 2 tablespoons per quart of warm water. (For heavier or sticky soil spots, sprinkle on damp sponge, rub and rinse; or make paste of soda.) Clean glass, tile, porcelain enamel, stainless steel sinks, chrome, fixtures, fiberglass tubs and showers. Remove coffee and tea stains from dishes. Clean and deodorize refrigerator.

Moderately Strong Alkali Cleaners Ammonia

Use solution of 2 tablespoons per quart of warm water to clean windows, glass, ovens, range burners, greasy surfaces. Use 1 tablespoon per quart warm water to wash painted walls and rinse well. Will remove some water based floor waxes.

Caution: Irritating fumes. Can soften paint, especially latex, if too strong. Has a slight bleaching effect. Always use alone because combining ammonia with other cleaners may produce lethal gases.

Moderately Strong Alkali Cleaners Borax

In mild solution, 1 to 2 tablespoons per gallon of warm water to wash sinks, painted walls, etc. Laundering (as diapers) to remove odors and retard bacterial growth.

Caution: Rinse thoroughly

Moderately Strong Alkali Cleaners TSP (Tri-Sodium Phosphate)

Buy at paint stores, especially ones painter use. Is part of some commercial cleaners. Use a solution of 1 tablespoon per gallon warm water to clean painted surfaces, porcelain fixtures, tile- glazed and unglazed. Removes soot and smoke (greasy dirt).

Caution: Always wear rubber gloves to protect skin; strong solutions remove paint. ALWAYS rinse thoroughly.

Strong Alkali Cleaners Washing Soda (Sodium carbonate)

Uses In hot solution, soak greasy burners, pans; dissolves grease from drains. Is builder for many powdered detergents.

Caution: Highly toxic; do not get on skin. Will darken and corrode aluminum.

Very Strong Alkali Cleaners Lye (Sodium hydroxide)

Uses are to clean grease from drains and open drains. Found in many drain and oven cleaners.

Caution: Very caustic and toxic; can cause serious burns to eyes or skin. Follow label instructions exactly.

Source :http://www.doityourself.com/stry/aluminum

Aluminum is a light-weight metal with a bright silvery luster. Small amounts of other metals are added to aluminum to make harder alloys for most uses. Its affinity for oxygen makes it resistant to corrosion and attack by most chemicals. Most aluminum used in visible parts of appliances is lacquered or otherwise coated, anodized or painted.
Aluminum reacts with air to grow its own thin oxide coating very fast. This hard, dark gray coating protects the metal. It's found on all bare aluminum surfaces, including utensils which, if rubbed on a counter or range top, or other material, makes a dark gray mark. If washed off the outside of the pan, it quickly forms again. A commercial process called "anodizing" thickens this coat and often colors it. Anodizing does not rub off. A special anodizing process produces a very hard, dark gray finish on professional type cookware.
Care depends on the product made from aluminum. Lacquers or waxes on products NOT used for food can protect aluminum against weathering and corrosion. Brighten aluminum utensils by cooking acid foods such as tomatoes, apples or rhubarb, or by boiling either 1 to 2 teaspoons cream of tartar per quart of water or 2 tablespoons vinegar per quart of water for 10 minutes in the pan. Prevent discoloration in the bottoms of double boilers or egg poachers by adding 1 teaspoon vinegar or 1/4 teaspoon cream of tartar to the water in the bottom pan. Remove stains from the outside of aluminum pans with silver polish, or mild, nonabrasive cleaner. Soap-filled steel wool pads scratch the outside surface, so use only when removing burned-on food or grease is more important to you than the scratched pan. Remove hard water mineral deposits (lime scale) from tea kettles where they have become crusted, boiling equal parts of vinegar and water for several minutes and letting stand an hour or so. The process may have to be repeated in severe cases. Rinse with plain water before using tea kettle.