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Re: [BKARTS] What?! isopropanol question



Wiki does good: "Isopropyl alcohol [isopropanol] forms an azeotrope with water at 87.4% alcohol. It is impossible to dehydrate isopropanol further using standard distillation methods. For this reason, more expensive means, such as using a desiccant, are necessary for production of 100% isopropyl alcohol."

I do not know if the azeotrope will affect leather, but alcohols are hydrophilic. A bottle of 100%, besides being expensive, will drop in percentage when the top is removed, absorbing water from the atmosphere. The notion that pure alcohol is needed as a solvent for this product seems unrealistic. If the product is thinnable with isopropanol, then I expect it contains alcohol, probably with a minimum of 12.6% water. A chemist could comment with more certainty...If the product works for the the use described, I can only assume that the azeotrope and/or small quantities of water are not deleterious and some thinning with "fresh" alcohol at 80-90% would be acceptable.


On Nov 8, 2006, at 7:58 AM, bndrboi wrote:


Ms. Wright seems not to know that even very small
traces of water will often cause old leather to
blacken and embrittle.
I'm sorry but her statement that isopropynol "is
always diluted to a 70% working solution... with
water" may well be true for her professional
applications but is the worst sort of dangerous and
ill considered nonsense in many conservation
applications, not just klucel solutions. One of many
situations is the solvent cleaning of paper where
media are water soluable. The use of klucel as a non
aqueous adhesive is another.

--- Heather Wright <Heather_Wright@xxxxxxxxxxxxxx>
wrote:

100% isopropanol solution is extremely flammable as
you are well aware therefore it is usually advised
to dilute the concentration to a 70% working
solution to avoid any chance that residual could
flash ignite (due to sparks, static, heat, flames,
etc.) The solution is comprised of ethanol, alcohol
and methanol sometimes. You will always dilute it
with water - and distilled if you have access to it.

Here is an explanation of the difference in purity:
 [

https://www1.fishersci.com/support/faq/faq_chem.jsp; jsessionid=FAL0T5Wx2mbUZFp4m1Kgh188ynUFfnItrFD1phxTKcWfhKj6UOYW!328433
]New Link

And here is an MSDS for Isopropyl:

http://www.soest.hawaii.edu/krubin/MSDS/isopropylether.html

Usually it will require a hazmat shipping fee if you order it. It is also recommended that for storing purposes that you put it in a flammable cabinet due to the increased volatilization of the solution at 100%.

I also agree, your university supply house should
have some on hand.
Best of luck,
H Wright
__________________________________
Heather Anne Wright
Biological Research Technician
New England Plant, Soil and Water Laboratory
USDA-ARS, University of Maine, Orono 04469
Campus: (207) 581-3362
Fax: (207) 866-0464

Book_Arts-L <BOOK_ARTS-L@xxxxxxxxxxxxxxxx> on
Tuesday, November 07, 2006 at 11:30 PM -0500 wrote:

On Nov 7, 2006, at 5:01 PM, Lavinia Adler wrote:


The answer seems obvious to me, but, since I'm
having trouble locating
100% isopropanol, I thought I'd take a chance on
learning that I'm
wrong.

Lavinia Adler


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<http://palimpsest.stanford.edu/byorg/gbw/gallery/100anniversary/>
For all your subscription questions, go to the
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See <http://www.philobiblon.com> for full information
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