Sciencemadness Discussion Board

New place to look for conc. acetic acid

Gearhead_Shem_Tov - 22-9-2010 at 06:38

I just found a new place for 30% acetic acid: in food-grade it's
used by cake decorators for "royal" icing to ensure quick drying
and a more even texture. It also helps keep the icing consistent
to minimise sagging.

GAA it's not, but if you have trouble getting OTC acetic acid more
concentrated than white vinegar, this might be a place to look.

-Bobby

The WiZard is In - 22-9-2010 at 10:24

Quote: Originally posted by Gearhead_Shem_Tov  
I just found a new place for 30% acetic acid: in food-grade it's
used by cake decorators for "royal" icing to ensure quick drying
and a more even texture. It also helps keep the icing consistent
to minimise sagging.

GAA it's not, but if you have trouble getting OTC acetic acid more
concentrated than white vinegar, this might be a place to look.

-Bobby



It may yet be possible to buy Kodak Glacial and 28% acetic
acid in a photo shop. Or you could use homeopathic chemistry
 — buy an empty Kodak 28% acetic acid bottle on eBay for $10...!

pantone159 - 22-9-2010 at 11:45

I've never seen the photo HOAc sold without an indicator (bromothymol purple???) in the solution. That kind of ruins it for me (unless my only intended use is as a stop bath!)

The WiZard is In - 22-9-2010 at 13:03

Quote: Originally posted by pantone159  
I've never seen the photo HOAc sold without an indicator (bromothymol purple???) in the solution. That kind of ruins it for me (unless my only intended use is as a stop bath!)



Stop bath solutions come w/ an indicator. The MSDS for Kodak
glacial acetic acid does not list any other ingredient, However,
nontoxic ingredients are not always be listed. Then -
given they have no way of knowing what concentration you
are planning on making - how would they know how much
indicator to add?

entropy51 - 22-9-2010 at 13:12

Quote: Originally posted by pantone159  
I've never seen the photo HOAc sold without an indicator (bromothymol purple???) in the solution. That kind of ruins it for me (unless my only intended use is as a stop bath!)
Distill it! The bromothymol blue stays behind in the still pot. You can distill it rapidly since you are not separating a volatile impurity. The stop bath I buy is usually over 90% acetic acid.

The Kodak glacial acetic contains no indicator but I haven't been able to find it in a photo shop for probably 10 years now.

pantone159 - 22-9-2010 at 19:28

Sorry, I meant that I have not seen the 28% stuff without the indicator. I have access to good quality glacial acid, but it would be nice to be able to have a convenient source of lower strength, as 100% HOAc can be kind of irritating to handle.

mewrox99 - 23-9-2010 at 02:02

Where I live 99% Acetic Acid is sold in most pharmacies.

One told me that it was Prescription Only medicine. The other sold me a 100mL bottle no questions asked

SWilkin676 - 23-9-2010 at 03:47

You can get 25% acetic acid vinegar at the oriental grocers. Strong stuff burnt my finger on it.

Also there aren't that many hobby photo shops around any more - even in big cities. It's the age of digital cameras folks. But there's hope on the horizon for acid's etc - check out biodiesel suppliers.
http://www.dudadiesel.com/

These guys shipped glacial pretty quickly - haven't tried it yet though.