Gold toner: titration or exhaustion?

[Rich Ullsmith]

What do you guys do?

I just went through a session with some toner that has been laying around for a while, think it was originally 5ml of 1% AuCl and 5g potassium thiocyanate. When toning times were getting up to maybe 10minutes, I just juiced it with 1 ml of the AuCl. This seemed to be good for another couple 8X10's.

Anything chemically unsound in doing this? At some point, does more thiocyanate need to be added? I do not know the chemistry of the reaction, but I don't think it is depleted.

Anyways, just wondering what you guys do. Tone to exhaustion, or replenish?

 

[jvo]

replenish... and replace

by count of number of prints, i replace the toner with new rather than have toner times lengthen.

i guess either method is valid, only one is more economical on money spent, the other more economical of time spent.

 

[dancqu]

I'm quite sure the gold serves the same purpose in combination
with thiocyanate as it does with the hypo in Nelsons Gold Toner.
The gold acts as a catalyst. With it the hue is altered and
toning proceeds at lower temperatures.

Up to a point Nelson's is a replenished toner. That of course
implies the consumption of the gold. The sodium thiosulfate,
of which there is plenty in Nelson's, is not replenished.

Have you given Nelson's a try? With Gold at $1200 an
ounce it might be worth a go. Dan