Any chemists around here? Isopropanyl alcohol

Mark:  I think that for our purposes, they’re almost the same thing.  According to Wikipedia, denatured alcohol is ethanol which has some additives to make it too yucky to drink.  In either case, they’ll dissolve or loosen the accumulated swarf and evaporate quickly.

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sksharp

As tcmeyer said, denatured alcohol is ethanol (the same type of alcohol that is in beer, wine and other beverages) with additives to prevent it from being drinkable. This is usually done so that the retailer can avoid having to pay the taxes and age restrictions that are imposed on the sale of alcoholic beverages. What is commonly know as isopropyl alcohol (properly known as 2-propanol) is very similar in chemical structure and therefore very similar in chemical properties to ethanol. 2-Propanol is most readily available as a 70% solution in water that is sold as rubbing alcohol in the pharmacy section of supermarkets. For the applications that you describe, I would expect that either ethanol or 2-propanol would be equally suitable. Use whichever one is cheaper and easier to come by.

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sksharp, Marc H

I just tried, both, 91% Isopropyl Alcohol and 91% Ethyl Alcohol to clean a used Diamond lapping film pair.  Both alcohols worked equally well and easily and quickly cleaned the film. Both alcohols evaporated almost as fast as I applied it and left no residue to be felt.

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Eagle Greg, sksharp, Organic

I cleaned the Lapping film with a paper towel. No paper residue was left.

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Mark76

sksharp wrote:

Organic wrote:

As tcmeyer said, denatured alcohol is ethanol (the same type of alcohol that is in beer, wine and other beverages) with additives to prevent it from being drinkable. This is usually done so that the retailer can avoid having to pay the taxes and age restrictions that are imposed on the sale of alcoholic beverages. What is commonly know as isopropyl alcohol (properly known as 2-propanol) is very similar in chemical structure and therefore very similar in chemical properties to ethanol. 2-Propanol is most readily available as a 70% solution in water that is sold as rubbing alcohol in the pharmacy section of supermarkets. For the applications that you describe, I would expect that either ethanol or 2-propanol would be equally suitable. Use whichever one is cheaper and easier to come by.

I first experienced the 91% Isopropyl for the cleaning of high end bowling balls made of resin. The 70% alcohol would leave a slight film, or residue behind and actually ruin the ball after a few uses. I don’t know but after that I use at least a 91% solution for any cleaning purposes.

Interesting. I assumed that the remaining 30% in a rubbing alcohol was water. I just looked into it and there are other things including <span class=”_Tgc”>perfume oils and denaturants. In that case, I would recommend going with a higher purity solution.</span>

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sksharp

Josh wrote:

I’m curious now… I’ve seen it recommended for years to “wet” the strop with a misting of rubbing alcohol, however, if it evaporates so quickly how does it actually moisten the strops? For cleaning many things I use acetone, it is a little more aggressive than ribbing alcohol but pretty amazing at degreasing and removing gunk (tape residue). I don’t use this on lapping film however.

The majority of the remaining 30% of rubbing alcohol that is not 2-propanol is water, so that doesn’t evaporate very quickly even though the 2-propanol does. I have only used my strops dry up to this point. Josh, do you wet your strops?

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sksharp