U of S | Mailing List Archive | alt-photo-process-l | RE: Vandyke Question

RE: Vandyke Question

On Sun, 24 Feb 2008, joachim oppenheimer wrote:

... I would
expect that, for the water to be the problem it would have to be so grossly
contaminated that you would smell it down the corridor.
Whatever the ultimate problem (or problems) may be, and whether or not Scott manages to pinpoint them, I can ASSURE you that the above sentence is 100% wrong (tho if you're talking bets, I never bet less than a million dollars).

The episode I mention was some years ago, but it was so startling it's etched well in mind. We'd already done VDB with no problem, then had to mix more. When we combined the solutions the silver precipitated out. Instantly, dramatically. The only change from the previous operation was a new gallon of "distilled" water, bought at the neighborhood hardware store where we'd bought it before... a sealed jug, official "distilled" label, etc.

It was odorless, colorless, and utterly did I say odorless? You wouldn't have hesitated to drink it. But with suspicions thus aroused, I brought it to the chem department, which tested and found it to be tap water. Tap water from where, I have no idea... but there was NOTHING patently noxious. The shock was getting it from our friendly neighborhood hardware store, but we figured the culprit was a rogue supplier. We got the next gallon from the supermarket and all was fine (tho a longer walk).

PS. I have as it happens done some testing of distilled vs. tap water in processes involving commercial photo paper, such as toning and bleaching. Also long ago, and less dramatic so not perfectly recalled. However, there were often distinct differences, often the tap water had better results... we figured the impurities from the NYC sewer system gave it an added complexity, like wine.