Glacial acetic acid.

[Mike Kennedy]

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A chap at the local camera shop just gave me a full bottle of the stuff. What do I use it for?

Mike

 

[Mackinaw]

Stop bath, once diluted.

Jim B.

 

[jeroldharter]

Most acetic acid that you by is 28% acetic acid solution. You dilute it to make stop bath. The glacial acetic acid is much more concentrated (so be more careful not to gat any on your hands). Therefore, you need smaller quantities to dilute it to a stop bath. The following is from the Freestyle website:

Mixing Stop Bath From Glacial Acetic Acid

You can make a working solution of stop bath from glacial (100%) acetic acid in two steps. First, dilute the full-strength acetic acid down to 28 %. To do this, mix 3 parts of glacial acetic acid with 8 parts of water.

For example, 3 oz. acetic acid + 8 oz. water, or 6 oz. acetic acid + 16 oz. water. Always pour the acetic acid into the water to avoid splashing.You can store the 28% acetic acid solution for later use.

Next, to make working solution: Measure our 48 ml (milliliters) of your acetic acid solution, and then add to 1 liter water.

 

[PhotoHistorian]

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A chap at the local camera shop just gave me a full bottle of the stuff. What do I use it for?

Mike

Mike-
Cut it 3 parts glacial acetic acid to 8 parts water and you will have 28% acetic acid and then use that stock solution at your usual short stop dilutions.

Walker

 

[Claire Senft]

It can be used in any formula that calls for acetic acid..stopbaths and fixers primarily.

It is a concentrated acid. Do not try to smell the vapor directly from the bottle.

If you use Potassium Ferricyanide in your darkroom, make sure that it NEVER comes in contact with any concentrated acid including acetic acid..You will be turning your darkroom into a gas chamber.

 

[Papa Tango]

Glacial acetic acid is an anhydrous (water free) form of acetic acid. This is some really strong stuff, and its vapors can burn your nose, eyes, and skin, and is very corrosive if spilled. Be really careful with it. If you want to have some chemistry experiment fun, put some in a clear bottle, refrigerate, and take a look at the crystals it will form! This is how it arrives at its name.

Otherwise, you can use it to make home-brew stop bath (non-indicator). It must be diluted to below 2% solution by volume in filtered or distilled water for that use. As with any acid, add the acid slowly to the water, not vice versa.

 

[Lopaka]

Also not that this stuff freezes at around 15 C (58 F) so doing the cut to around 28-30% to store will make mixing stop as you need it less bothersome and resolve the temp storage issue.

Bob

 

[Ole]

I used to keep a small bottle of the stuff in my darkroom. If it was solid, the darkroom was too cold to work in. I would put on a little heat, and try again next day.

 

[Peter Black]

The MSDS is at the link below. Be aware that this is pretty nasty stuff in its present concentration.

Dead Link Removed

 

[Photo Engineer]

I safely keep a 1 gallon bottle of glacial acetic acid in my darkroom and have for years. Kodak sells it in 1 gallon containers. I use it to mix stop and fix.

PE

 

[Jeremy]

you can always send it to me so i don't have to purchase any before i begin my wet plate endeavors. i'll trade you a bottle of indicator stop bath for it (since that's what this stuff appears to be diluted down for anyway)

 

[Mike Kennedy]

I'd love to Jeremy but Canada post got all bent out of shape when I asked about mailing some technidol to a friend of mine in Canada. I'm affraid that sending it to Texas would magnify Can.Post frown into a snarl.
God only knows what would happen if the container leaked. (Visions of jack boots kicking in my door at midnight)
I have 8 packages of Technidol and 3 boxes of Kodak chemestry (turning T-Max 100 into slides) sitting in the basement.Free to you if you want to pick them up.

Mike

 

[Jeremy]

Haha, no prob, Mike, didn't even check to see where you were located.

I'd love to Jeremy but Canada post got all bent out of shape when I asked about mailing some technidol to a friend of mine in Canada. I'm affraid that sending it to Texas would magnify Can.Post frown into a snarl.
God only knows what would happen if the container leaked. (Visions of jack boots kicking in my door at midnight)
I have 8 packages of Technidol and 3 boxes of Kodak chemestry (turning T-Max 100 into slides) sitting in the basement.Free to you if you want to pick them up.

Mike

 

[Photo Engineer]

Unite the US and Canada and get the worst of both postal systems.

Just a joke, but both postal systems are pretty bad.

PE

 

[gainer]

A story. When I was a student at WVU, the chem lab had gallon jugs of various reagents including glacial acetic acid with blow tube devices consisting of a siphon tube that went to the bottom of the jug and a blow tube, the other end of which was supposed to be above the liquid level. One day I went to get some and did not notice that the lab assistant had both tubes below the liquid level. I got what I needed and when I let up on the pressure, I got a mouthfull of Glacial acetic acid. EXTREMELY strong vinegar! Thank goodness it wasn't concentrated sulfuric.

 

[jim appleyard]

Unite the US and Canada and get the worst of both postal systems.

Just a joke, but both postal systems are pretty bad.

PE

But the Canadians have better beer and better health care!

 

[PeterB]

my calcs give me 27%, not 28% stock concentration.

You can make a working solution of stop bath from glacial (100%) acetic acid in two steps. First, dilute the full-strength acetic acid down to 28 %. To do this, mix 3 parts of glacial acetic acid with 8 parts of water.

I'm not a chemist, but I am an engineer with a penchant for details. How does one arrive at 28%?
I calculate 100% x (3/(3+8)) = 27.3% which rounds down to 27%. Where am I missing the extra 1% ?

regards
Peter

 

[Ken Nadvornick]

Where am I missing the extra 1% ?

You're not. A 7+18 (acid+water) dilution will do the trick correctly. The 3+8 dilution is simply good enough for government work...

Ken

 

[PeterB]

You're not. A 7+18 (acid+water) dilution will do the trick correctly. The 3+8 dilution is simply good enough for government work...Ken

Perfect ! I like it when the maths works out. Although the 'easier to mix' dilution of 3+8 still gives closer to 27% and I think folks are just being lazy when they knowingly propagate erroneous figures.

regards
Peter

 

[Photo Engineer]

Well, it gets even worse when you consider that glacial acetic acid is not 100%. It varies from 98 - 99%.

PE

 

[fschifano]

And in the end it still doesn't matter if you are using to mix up a stop bath or an acid fixer.

 

[Gerald Koch]

Be careful with glacial acetic acid, what most people do not realize is that it's flammable. That is why only 60% acid can be shipped now.

 

[Photo Engineer]

Glacial Acetic Acid, EK cat # 64-19-7 for 1 gallone and 146-2837 for 1 pint. IDK if it is still available, but I have about 1/2 bottle of each on my shelf.

It is flammable, but also available. Acetone and all alcohols are flammable, but are still available at home repair and some auto stores.

The flash point of HOAc is pretty high. (HOAc is chemspeak for glacial acetic acid).

PE