Re: Rubbing alcohol = Isopropyl alcohol? Acetic acid?

[Richard Knoppow <dickburk@ix.netcom.com>]

-----Original Message-----
>From: etienne garbaux <photographeur@nerdshack.com>
>Sent: Sep 23, 2007 3:16 AM
>To: alt-photo-process-l@usask.ca
>Subject: Re: Rubbing alcohol = Isopropyl alcohol? Acetic acid?
>
>Ross wrote:
>
>>My local phamacist would have to order in a litre of Isopropyl Alcohol 70%,
>>but has 250ml containers of "Rubbing Alcohol" Are these the same? Intended
>>use: to harden the first albumen coat.
>
>Here in the US, "rubbing alcohol" is generally about 70% isopropyl 
>alcohol with a bit of oil and sometimes glycerine or the like so it 
>doesn't dry out your skin as badly as plain alcohol would.  The 
>additives are often unwelcome in photo chemistry, but I have never 
>tried setting albumen with rubbing alcohol so I can't say if it would 
>do any harm.  Pharmacies and some hardware stores here also stock 91% 
>or 99% isopropyl alcohol (with no adulterants) in pints and smaller 
>bottles.  A farm supply store may have it for use as a disinfectant 
>(sterilizing needles, etc.).  Electronics stores may sell it for 
>cleaning circuit boards and dissolving solder flux.
>
>>And is 28% Acetic Acid the same as Glacial Acetic Acid?
>
>No, glacial is 99% acetic acid (approximately).
>
>Small world -- I spent a good part of a year in your neighborhood 
>some time ago (from Lithgow to Wallarawang, mainly, but I did see 
>most of the East Coast from Sydney to about the middle of the Reef 
>and returned to Lithgow along the Great Dividing Range).  It was a 
>great time!  I hope to get back again.
>
>Best regards,
>
>etienne 
>
>
     At least in the USA the container must say what is in it. Most rubbing alcohol is just 70% Isopropyl but some has Oil of Wintergreen in it. Its marked that way and is often colored green. Many drugstores carry 91% Isopropyl and some 99+% percent. Isopropyl will absorb water from the air but reaches equilibrium at about 91%. Kodak currently recommends 99+% for cleaning negatives. 
     Note that some rubbing alcohol is Ethyl alcohol, usually marked as such but its denatured with something, often Methyl alcohol, to make it undrinkable. 
     When I can't find 99% at the drugstore I get it at Fry's the computer and electronics store. 

--
Richard Knoppow
dickburk@ix.netcom.com
Los Angeles, CA, USA