> John
>
> I caught the disodium point as your instructions are so clearly set out.
>
> Just a few input/output points.
>
> If Rising took out the size why not put it back in again with deionised ossein
> ?
>
> What difference does it make if one uses Iron III oxalate ? I make this up
> cheaply in the dark room.
>
> Which gold chloride ? My Johnson Mathey Catalogue lists gold chloride, AuCl 3 at
> L795.90 for 5 g (glycine is on the opposite page for L 15.90 for 500 g, this
> comment is for those interested in 19 century developers). But H Au Cl 4 at
> L110.50 for 5 g.
>
> We did a bit of mole crunching on the basis of the proportions and came up with
> some very funny answers. Is it possible to express this in terms of percentage
> solutions ? Particularly of the gold chloride because I do not want to pour too
> much of it down the drain even at the lower price.
>
> It is only this part of the sensitiser that caused us difficulty.
>
> Thanks again
>
> Terry.
>
Terry, good to hear from you, as I received no messages for 3 days, and
wondered what wrong I had committed to be spit off the list.
1) While I really liked the Gallery 100, I switched because I was
unaware of using deionized ossein to resize. It sur seems like we
shouldn't have to do this. I became so frustrated with the Gallery
because I discovered the change halfway through a 150 print platinum
portfolio printing job. Could you give me some more info on the ossein?
2) I used Mikes suggestion of the ferric ammonium oxalate because it was
cheap ($24 /lb) and easily available. The commerciual source for ferric
oxalate has recently gone up to about $50 for 100gm. which is hideous. I
beleive that ferric oxalate would work fine (I haven't tried it though)
if the molar relationship remain constant) Perhaps Mike Ware could
respond to this.
3)I used the HAuCL4. I beleive this is known as hydrochloroauric acid,
thoough my bottle of reagent is labled "gold chloride" With the waters
of hydration it has a molecul;ar weight of 393.88. We want to wind up,
in the final sensitizer, with 0.15M solution of gold. That means that
part A must contain 0.45 M gold solution. According to my calculations,
10 ml. of .45M sodium hydroxide plus 1.76 grams of gold chloroide will
fill the bill. This should be rthat same as 0.9M NaOH plus 35.4% gold
chloride, in equal amounts. Do your calculations agree with this?
John