The rubbing alcohol from the drug store may not be isopropyl alcohol. Some rubbing alcohol is actually ethyl alcohol. Check the bottle. Also, as Joe said, the stuff from the drug store may contain other oils/esters. Again, check the bottle. In my experience, the alcohol from the drug store is far more expensive than simply buying methanol (methyl alcohol) or ethanol (ethyl alcohol) from the hardware store and diluting it to the desired strength. For piano stuff, there's no point in buying denatured alcohol because we dilute it with water anyway. Refinishers may need the denatured stuff, I'm not sure. In general I've found that methanol the best medium to get the water into felt. It also evaporates a little faster. To each his own. Larry Beach, RPT Vancouver BC Canada
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