Tucker:

Muriatic acid is, as you said, the commercial grade of hydrochloric acid. Muriatic acid is sold for fluxing solder joints as well as cleaning mortar from bricks before they are reused. You can buy it from a plumbing supply as "Soldering acid," or from your buidling supply storefor masonry cleaning.

For cleaning aluminum it is usually sprayed on, the acid content is neutralized in its action but there should be a post rinse anyway. The reation is HCl+AlO -> Al+H2O+Cl (Didn't try to balance the equation, please excuse). The free chlorine product says do it only in a well ventilated place. If the reaction is allowed to run too long, or if the acid is too strong, you get aluminum chloride, and the bottom removed from your pan.

The reaction with zinc (any "Pot" metal) is much more energetic. HCl+Zn -> ZnCl + H, leaving us with a Zinc Chloride solution and free hydrogen. If you do this one, the ZnCl solution is a good soldering flux all by itself.

Check with your AutoMagic salesman about concentrations.

Bill.