Dry Ammonium Thiosulfate

[MurrayMinchin]

Hi there,

I've heard people mention here that they have used dry, crystal, or granular ammonium thiosulfate. Where can you get it in Canada? In the U.S.? I'm trying to avoid the cost of shipping water thousands of miles.

It must be viscious, nasty stuff...mix outside - long rubber gloves - eye protection - respirator rated for such stuff...anything else I should be aware of IF I can get it?

Thanks.

Murray

 

[titrisol]

Ammonium thiosulphate can't be worse than ammonium bicarbonate used in baking (regarding viscious, nasty, whatever)
I'd go for granular, since that would be easier to pur and less airborne powder which is the one that smells bad.

The simplest way to mix this would be to put the powder into a piece of cheesecloth to make sorta teabag and let it dissolve by itself.
It may take a couple of hours but no powders flying everywhere, and no need for respirator and oxygen mask.
It also helps to work in a moist environments instead of a very dry one to keep the powder to go airborne too much.

 

[ann]

try jdphotochem.com they are a Canadian company

 

[nworth]

It's a pretty ordinary white powder. The problem is that it is hygroscopic, and you are never sure just how much water it has absorbed. That makes measurement impossible unless you have kept it scrupulously dry.

 

[Gerald Koch]

Some years ago I had a similar idea to buy anhydrous sodium thiosulfate and not pay for water in the pentahydrate. Unless I was very careful the anhydrous stuff would absorb enough moisture to set like concrete.

 

[Lowell Huff]

Dry Amm Thio is available at your local plant nursery as SULFATE OF AMMONIA, grass fertilizer.

 

[Photo Engineer]

My suggestion....


Don't use dry ammonium thiosulfate.

Kind of like buying a pound of phlogiston. Not very reliable. ~smiles~

PE

 

[srs5694]

Kind of like buying a pound of phlogiston. Not very reliable. ~smiles~

For those not up on the history of science, a brief description of phlogiston can be found here, among other places:

http://www.infoplease.com/ce6/sci/A0838824.html

Briefly: It's part of a discredited 18th-Century theory of combustion; combustible materials were said to contain plogiston, which was released by combustion.

We now return to your regularly scheduled thread....

 

[jim appleyard]

For those not up on the history of science, a brief description of phlogiston can be found here, among other places:

http://www.infoplease.com/ce6/sci/A0838824.html

Briefly: It's part of a discredited 18th-Century theory of combustion; combustible materials were said to contain plogiston, which was released by combustion.

We now return to your regularly scheduled thread....

Silly me! And I thought phlogiston was a former Soviet bloc country!

 

[MurrayMinchin]

Silly me! And I thought phlogiston was a former Soviet bloc country!

Phew! And I had images of a leather clad, whip wielding woman laying down a pound of phlogiston on my a$$!

Murray

P.S. Guess I'll be paying to ship water again...

 

[jim appleyard]

Is it possible to make ammonium thiosulfate from scratch? Perhaps that way is can be made in small enough amounts to avoid the hygroscopic problem?

 

[pnance]

What the idea of making it in solution? Doesn't 60 parts, by weight, sodium thiosulphate and 40 parts ammonium chloride make ammonium thiosulphate (and some table salt, sodium chloride).

 

[pnance]

and some water

 

[Tom Hoskinson]

What the idea of making it in solution? Doesn't 60 parts, by weight, sodium thiosulphate and 40 parts ammonium chloride make ammonium thiosulphate (and some table salt, sodium chloride).

Yes. Take a look at the OF-1 Fixer recipe in the Apug Chemical recipes.

If you don't care for the chloride, you can use ammonium sulfate instead of ammonium chloride.

 

[pnance]

Is OF-1 a stock or working solution?

 

[Photo Engineer]

If you mix 1 mole of sodium hypo and one mole of ammonium chloride, you get one mole of a mixture of salts, but the goal of using ammonium salts, and the reason that an ammonium fix works so well is due to the fact that ALL other counter ions are removed or absent. So, if you want ammonium hypo activity, you must eliminate all sodium ions. This is what fails when you try to make ammonium hypo yourself.

It takes a sophisticated plant or operation to make pure ammonium thiosufate, and to boot it is not very stable as a dry powder.

PE