Denatured alcohol and Isoproply alcohol

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I know everyone in the world probably knows this but me, but what is the difference between isopropyl alcohol and Denatured alcohol? I use the denatured kind to wipe off pencil marks without having to resort to sanding, but at work we have 55 gallon drums filled with isopropyl alcohol.

Might save me some money if the two had similar properties....
 
Denatured is what we always used to clean tape player/recorder heads. Isopropyl had something in it that left a film on the head that was not good for the tape or the music transfer, can't remember. I "think" denatured is what you would use with wood, not the Isopropyl, but let's let the mor knowledgeable ones on the matter answer that. Jim.
 
The [first hit] I got from a Google search on denatured isopropyl was fairly informative without getting too technical.

Apparently, "denatured" starts out as ethanol, the eminently drinkable stuff. "Rubbing alcohol" may or may not have ethanol or isopropyl in it, so you can't go by that. But ethanol and isopropyl definitely seem to be distinct from each other.

Someone could probably do more research on the properties of the two types, but the best way to answer your question might be to bring an ounce or two of isopropyl home and try it on those pencil marks. :dunno:
 
I'm not a chemist but there are a number of different alcohols - ethanol, methanol, isopropyl, isobutyl, etc. The differ in their structure and number of carbon/hydrogen groups.

Ethanol is denatured because it can be consumed by humans in the un-denatured form - and the only way you get the un-denatured product is to pay the alcoholic tax on it.

I don't know the reason why different alcohols are used. I notice that isopropyl is used in the medical field to wipe the skin before a shot. Maybe someone else can tell us what the differences are in the different kinds of alcohols.

Oh, Wikipedia has an article on alcohol which might explain some of it.

Mike
 
I've got to believe they use something different for deicing now. A few weeks ago I was flying out of Detroit and we had to go to the deicing pad. The smell was not an alcohol smell and they did it with the engines running. In fact they revved them up when they sprayed around the wings. Knowing very roughly how a jet engine works that seems like it would be really dangerous.

Edit: I was curious so I looked it up. It seems that they are Ethylene and Propylene glycol-based: http://www.dow.com/aircraft/products/index.htm. At least some of them anyway.
 
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I have a bottle of Nail Polish Remover that is 100% acetone (nasty stuff). Is Isopropyl just as nasty? If so, using it on your skin at 70% concentration would seem like a bad idea.... :dunno:
 
I'm not sure...at work they use Isopropl alcohol by the carpenters. They use it on wood all the time, but again, I am not sure why they use that and not denatured alcohol. Someday I'll ask someone that knows, though it may be just because its cheap. As I said, they use it by the barrel full.
 
I have a bottle of Nail Polish Remover that is 100% acetone (nasty stuff).....

I promise not to ask why you have a bottle of nail polish remover:huh: but thought it was acetone. I usually keep a qt can of acetone around and have occasionaly used it to wipe sticky stuff off my hands. It does have a tendency to dry and chap out your skin, but if you follow it up with a regular hand washing, no problem.
 
Isopropyl alcohol is usually 70% alcohol by volume and is usually made from wood byproducts. It's a good solvent for oils on skin and at 70% strength does a good job of disinfection of skin by making bacteria clump together and it dehydrates them. Isopropyl is toxic if consumed and can be fatal. Ethanol is produced from food products (grains, potatoes, corn, etc...) and can be any strength but, usually is sold in it's anhydrous form (90-95% pure ethanol). Pure ethanol is drinkable and since our country likes to tax what it considers vices, the government requires alcohol taxes be paid for consumable ethanol. Denatured alcohol is ethanol that has another organic constituent, like phenol thalene, added that make consumption either dangerously unpleasant (active component of laxatives) or toxic.

All alcohols can burn but, isopropyl is fairly low on the flamability list because of the high water content (30%). Now, is that more than you ever wanted to know about alcohol?...
 
No way Chris, that was great, thanks for the info!!

had a customer ask me once, what they make "Potato Vodka" from............:doh::rofl::rofl::rofl::rofl:

Yeah, the last thing he needed was some vodka :rolleyes: :wave:
 
I've got to believe they use something different for deicing now. A few weeks ago I was flying out of Detroit and we had to go to the deicing pad. The smell was not an alcohol smell and they did it with the engines running. In fact they revved them up when they sprayed around the wings. Knowing very roughly how a jet engine works that seems like it would be really dangerous.

Edit: I was curious so I looked it up. It seems that they are Ethylene and Propylene glycol-based: http://www.dow.com/aircraft/products/index.htm. At least some of them anyway.

Perhaps different now. I was thinking back to 1959 when I was in the Air Force.
 
I promise not to ask why you have a bottle of nail polish remover:huh:

I wondered when someone might wonder about that. :rolleyes: Between Norm wiping down oily woods with acetone and folks on a motorcycle message board using it to clean up certain motorcycle parts, I figured I needed to get me some. But ... wasn't no way I wanted to bring home a gallon of it! (The only size I could find at the Borg back then.)

I happened to be standing in a salon supply place a few years ago (accompanying my wife on an errand) when I noticed a 12-to-16 ounce bottle of Fingernail Polish Remover: 100% Acetone. Perfect!
 
With the different types of alcohol mentioned comes different uses too.

Most every type of alcohol is great for cleaning but not all alcohols are good for everything.

As Chris mentioned, the biggest difference between Isopropyl alcohol and Denatured alcohol is the water content. Now as far as woodworking goes, shellac flakes are dissolved in alcohol and can't have much (preferably no) water in it or it won't lay down, cure or harden correctly. Shellac is one of the oldest finishes used and the outcome or uses for it are so good, that it can be and should be considered for most wood working projects. One of the nice things with shellac is that it's a non toxic finish and once cured (alcohol flashed off) can be consumed (ever wonder what is coating your fruit and veggies to make them nice and shiny or that coating on your morning vitamins that help them slide down easier?)

Ok, off the Shellac bandwagon, back to the alcohol :eek:

Anyone remember moonshine, grandma's special medicine or the southern boys hooch? That was ethanol. Strong stuff right? The main reason pure ethanol became regulated and denatured was during prohibition in order to allow for other uses (medical etc...) for the alcohol. Denaturing as Chris mentioned renders the alcohol toxic which generally would keep people from consuming it. The tax reason to my understanding came after prohibition.

In Canada, Methyl Hydrate is the same thing as denatured alcohol in the US and is known by many brand names, everclear is one.

So, if you're going to give shellac flakes a try, you'll need some denatured alcohol to dissolve those flakes (it's a ratio dependent on the solid content of the finish you want). For some good reading on shellac take a look at Shellac.net
 
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".......the biggest difference between Isopropyl alcohol and Denatured alcohol is the water content. Now as far as woodworking goes, shellac flakes are dissolved in alcohol and can't have much (preferably no) water in it or it won't lay down, cure or harden correctly. "

Makes sense. The water based (know that is not the right term :huh:) Varathan Poly spray can I bought yesterday has Isopropyl in it.
 
Not to belabor the point but, Isopropyl and ethanol are organic compound with differing chemical components (the number of carbon atoms and such) and one is not just an adulteration of the other. Everclear (at least what I've seen sold at adult beverage stores) is 95% ethanol and drinkable but, not survivable in large quantities, at least that's what I remember from my college fraternity days...
 
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