No luck with the acetic acid - my stop is citrus based, and the local shops don't have an acetic based one in stock (and I won't get anything mail order before the holiday). I think I'll give it a try with the rectified spirit. Here's the recipe that uses this...
Adjusted for 500ml of albumen, the quantities work out to...
So, compared to the 'reference' recipe above, the salt is a bit weaker, the proportion of spirit is higher, and the distilled water seems much higher. The book later says to use a 13.5 to 14% solution of silver nitrate. It's hard to say whether the spirit should be reduced, since it may have a different effect compared to the acetic acid - I'm tempted to keep the proportion of that the same. The amount of water does seem a bit high - any comments on that? Tentative proposed recipe...
* 500ml albumen
* 6g ammonium chloride
* 5g sodium chloride
* 15ml distilled water (better to use this smaller amount?)
* 17ml rectified spirit
* 15g sodium citrate (or 11g to match the salt?)
* 2 drops Kodak PhotoFlo (optional)
Mixing the two chlorides to see if I get an in-between colour that tends towards a brown or sepia after Kodak rapid selenium toner. Also have potassium dichromate to add to the sensitiser.
Thoughts? (I realise there's an element of suck-it-and-see - just looking to eliminate any potential disasters.)
Just made the albumen mix. I got 300ml of albumen, so I adjusted the proportions to suit. I went with the original amount of sodium citrate on the basis that the amount of preservative is to match the amount of albumen. Forgot to add the wetting agent, but I don't think that's critical. I found that the powders struggled to dissolve in the amount of water and spirit, so I just did what I could and bunged it into the albumen. The electric whisk turned it into meringue consistency in a couple of minutes or so. Now being left to settle.