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Hope it's ok to revive a 5-year old post..

I have Copper Sulphate Pentahydrate, which is the most common form AFAIK, so would that be the weight-for-weight equivalent of the Cupric Bromide, or should the anhydrous equivalent be used?
According to this page, 15 grams of the pentahydrate is equivalent to 10.45 grams of anhydrous, so the pentahydrate contains about two thirds of the active component. https://sites.google.com/site/paradoxhomechemistry/experiments/make-anhydrous-copper-sulfate#:~:text=Anhydrous%20copper%20sulfate%20will%20be,of%20crystallization%20and%20becomes%20anhydrous.

Or is it not that critical?

Thanks JR, I have found a few international sources, including ebay.
I'll give the Sulphate a go first as it's available locally.
If it doesn't work, I'll have no other choice but to import the Bromide and deal with customs' questions.

On US eBay, $2 US per gram: http://www.ebay.com/itm/281241987744

[quote="MrBungle"]Thank you gentleman for the metol tip, I had already looked at PBU-metol but decided against it having read Hans' own preference for the Amidol version in his book '[i]Silver Halide Recording Materials[/i]':

[i]"The amidol version produces probably the cleanest results and shows the highest bleaching rate, but the bleach bath is not as stable as the -metol version."[/i][/quote]

I guess that's referring to coarser grained emulsions principally (Agfa, Ilford PFG-03 etc.), where amidol stain masks noise (very much like the effect from pyrogallol development).
With finer grains the amidol stain may become a nuisance though.



[quote]Martin,
I was never good at chemistry, I'm guessing by your suggested substitute that it is the Copper, not the Bromide that is needed?
As I've lost some bromide and gained sulphates, would there need to be an adjustment of the other constituents to get things back in balance or is it not worth considering due to the very small part of the overall make-up? (~1.2%)[/quote]

I'd simply add the same quantity of copper sulfate instead of copper bromide.
I seem to remember that the PBU formula was based on a similar bleach by Pollakowski (?). The copper part of these bleaches is meant to stabilize the solution.

Thank you gentleman for the metol tip, I had already looked at PBU-metol but decided against it having read Hans' own preference for the Amidol version in his book '[i]Silver Halide Recording Materials[/i]':

[i]"The amidol version produces probably the cleanest results and shows the highest bleaching rate, but the bleach bath is not as stable as the -metol version."[/i]

To me, superior holograms is an easy choice over a slightly longer lifetime for the bleach.
I can easily make smaller batches of bleach, I don't [b]have[/b] to make 1L at a time :D
Either way, Metol is reasonably cheap so I'll add some to my chem order to have a play.

Martin,
I was never good at chemistry, I'm guessing by your suggested substitute that it is the Copper, not the Bromide that is needed?
As I've lost some bromide and gained sulphates, would there need to be an adjustment of the other constituents to get things back in balance or is it not worth considering due to the very small part of the overall make-up? (~1.2%)

Many thanks.

FYI:

PBU-metol (Bjelkhagen-Phillips)
cupric bromide 1 g
potassium persulfate 10 g
citric acid or sodium hydrogen sulfate 50 g
potassium bromide 20 g
metol 1 g
water (distilled) 1 l

undiluted (does not work until 30 min after preparation), transmission/reflection, fixation-free
can be used about 90 minutes after mixing

Hi
I assume you can easily replace the cupric bromide with cupric (copper) sulfate (CuSO4).

As for using Amidol in the PBU bleach, it doesn't form a long-lasting solution - maybe just one week or so. You might be better off with Metol.

Hello all.
I'm pretty sure the answer will be a resounding 'No' but doesn't hurt to ask. Hopefully Hans Bjelkhagen visits this forum?

Is there an alternative/substitute for the Cupric Bromide in PBU-Amidol?

I'm able to obtain everything else I need with relative ease (already have the Amidol), but I'm unable to source the Cupric.
Neither Photographers' Formulary, nor ArtCraft nor Vanbar (photography chem supplier here in Australia) seem to have this.
I've tried searching Copper (II) Bromide also, but still no hits.

Many thanks in advance.
Simon