Wrong chemicals and alt. processes

[Ole]

Getting hold of chemicals in Norway is a lot more complicated than you would think; it certainly is a lot more complicated than I would have thought.

First, there is only one supplier of general chemicals.

Second, they only sell to businesses, not private customers.

Third, they have the worst internet catalogue and ordering system I have ever seen.

Fourth, they have a CD-ROM version of the catalogue which is totally different from the online version: Different content, different names, different order numbers.


As it happens, I do own a registered business, even if I just keep it for things like this.
I also have a degree in chemistry and am familiar with several naming conventions. I also have some experience in database design and search criteria.

I have managed to get all I need (in quantities large enough to last me into my next life) - except for green ammoniumferricitrate (or ferrioxalate, but I can make that).

This supplier lists two versions of (NH4)Fe-citrate, with no mention of colour. So I bought the one with the highest concentration of iron. It's bright rust red.

The other version, I eventually managed to worm out of the database, is "pale brown"...

But the red stuff works, even if all I've read about exposure must be changed. It seems to give lower contrast, with a tendency to get very dark very quickly.

Any advice as to what changes I should make? Or should I sit down and try to work it out myself? Maybe next time it rains for a week - or month - I'll try that anyway. In the meantime, I'd be grateful for any and all suggestions.


Alternatively,
Ole Tjugen

 

[Jorge]

What process are you doing? pt, pt/pd, pd, salt? It all depends on what do are doing to be able to give you some advice on changing printing times and developing.

 

[Aggie]

..

 

[Ole]

I can't believe I forgot that!

So far, I do van Dyke.
I also do salt prints, but my silver nitrate is at least the right chemical...

I intend to try Pd sometime in the future, I even have the Palladium already. I also have a 5x7 neg I think will look good in (cyanotype) blue.

But for the moment, my main concern is van Dyke - thus the ammoniumferricitrate.

As I mentioned, I have a degree in chemistry so making a ferrioxalate solution should be no problem. But the ammoniumferricitrate is a very poorly defined chemical with variable composition - besides, the only specifications I can find for "The good stuff" is "green". I can't synthesize "green"!

Thank you
Ole

 

[Robert]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (OleTj @ Mar 17 2003, 02:46 PM)</td></tr><tr><td id='QUOTE'> good stuff&quot; is &quot;green&quot;. I can't synthesize &quot;green&quot;!
</td></tr></table><span class='postcolor'>
Food colouring?-)))

Is it possible the chemical is used for something else? If you can find out what the industrial use of the chemical is then you can try that route to get it. I hear swimming pools use hypo-)))

 

[LFGuy]

CAS number 1185-57-5

As far as I know, the brown stuff has more iron in it than the green stuff (Fe:14.5 -16.0%)

Here's from a search I found:
Dead Link Removed

It seems that the brown will work, but it is not as sensitive as the green stuff.

 

[Jorge]

</span><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (OleTj @ Mar 17 2003, 01:46 PM)</td></tr><tr><td id='QUOTE'> I can't believe I forgot that!

So far, I do van Dyke.
I also do salt prints, but my silver nitrate is at least the right chemical...

I intend to try Pd sometime in the future, I even have the Palladium already. I also have a 5x7 neg I think will look good in (cyanotype) blue.

But for the moment, my main concern is van Dyke - thus the ammoniumferricitrate.

As I mentioned, I have a degree in chemistry so making a ferrioxalate solution should be no problem. But the ammoniumferricitrate is a very poorly defined chemical with variable composition - besides, the only specifications I can find for &quot;The good stuff&quot; is &quot;green&quot;. I can't synthesize &quot;green&quot;!

Thank you
Ole </td></tr></table><span class='postcolor'>
Ah, if you have to have ammonium ferric citrate I would expose for 1/3 less than the higer purity. OTOH I use ferric oxalate to print Kallitypes and it works great. I would suggest you use ferric oxalate. As you know none of these light sensitve chemicals are very stable and I think AFC is less stable than FO. I order mine from B&S and the powder form lasts a long time. Of course making your own is ok, but IMO why hassle with it? If the order of FO plus shipping is less than the time and expenditure you would have if you do it yourself why not go with B&S or Artcraft, they will ship to you and when I used artcraft in the mail, with the famous burro it only took 2 weeks.

BTW if you want formulas for making Ferric oxalate let me know and I will post them here or send you the URL for the web site who publishes them.

 

[Ole]

Thank you all!

My conclusions so far are these:

Brown will work - some recommend using more, some recommend using less. Will try both. Would be nice if I can find out the stoichiometry - will have a look at it later.

Next time I'll buy the pale brown, which seems to be the low-iron green under a different description. But I have enough brown stuff to last me a lifetime or so - 500g was the smallest package of "technical" grade, at less than half the price of 10g "Ultrapure"...

Ferric oxalate is not listed in any of my supplier's lists - under any name I can think of. But mixing Fe(OH)3 with oxalic acid, with a little H2O2 to maintain the oxidation state, should give ferrioxalate in solution. It may need a little extra acidifier, but I doubt it.
I'll also try importing some from the UK - if customs will let me.

 

[Ole]

Interim update:

The brown stuff seems to give more, not less contrast. However it is also more susceptible to "fog", and must be coated, dried and exposed faster.

I'm going to try diluting the mix a little more, as it seems very "thick". I might also add a little more silver to the diluted mix, and a fraction of a drop of 3% hydrogen peroxide if fogging continues to be a problem.

Postcard list members may get to see the results of my experiments, as I'm testing on postcard stock