Sorry, it probably does come in different strengths depending on the country. Pure Ethanol is not pure ethanol; the drinkable form is 95% EtOH and 5% water; the lab form is 99+ % and benzene. The alcohols form an azeotrope with water so that they act as one molecular group. One has to form another azeotrope with benzene to get a higher percent. The same applies to the other lower molecular weight alcohols (and to some extent with the higher molecular weight alcohols/"waxes"). Other solvents lacking the hydroxyl (OH) group would make for less oxidative solvents, but are not readily available. Others are such good solvents, such as Acetone, they may dissolve a wee bit too much of plastics, paints, and adhesives.
In general, Isopropanol is cheap and effective bearing in mind that the water molecule is electron "rich" and will conduct electricity (electrons); probably why allowing it to dry out over night is best. Further, the OH (oft shown as OH-) group loves metals (oft shown as Me+) and make, for example, FeOH3 or rust. This is called "oxidation" for the addition of Oxygen. In electronics it is not good. Throw in a "Basic" alkaline like Lye (KOH Potassium Hydroxide) or as in the case of our friend the barrel battery, and not only does it oxidize, it also dissolves the copper traces. No, "Acid" batteries use lead (Pb) and sulfuric acid and are found in cars. Well, not hybrids, but you should know the difference.
Last edited by Cymru; 19 June 2013 at 18:26.