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

Re: Vandyke Question

Another thing I mentioned last time was that sometimes "distilled water" isn't... I had some checked at our chem lab & what was sold as distilled was regular tap water.


On Fri, 22 Feb 2008, Christina Z. Anderson wrote:

I just mixed up a batch of this exact formula and no precipitate occurred. BTW, we have used year old VDB and it works fine, so hopefully you didn't throw the old stuff away?

This problem was reported to the list not too long ago and I cannot remember what the consensus was but I seem to remember that if you let the stuff sit for a while it'll go into solution, and that if you stirred the two solutions together too quickly that could be the cause of the precipitate falling out of solution. I did heat up my water, though, and perhaps that is why I did not experience that precipitate.

----- Original Message ----- From: "Scott Wainer" <swphoto@verizon.net>
To: "Alt Photo List" <alt-photo-process-l@usask.ca>
Sent: Friday, February 22, 2008 4:19 PM
Subject: Vandyke Question

Good day List,

I recently decided to print some images in vandyke and found a 2 year old bottle of sensitizer hidden on the shelf. Thinking it was too old to use, I mixed up a new batch only to find that when I added part c the sensitizer turned cloudy and eventually separated with a clear liquid on top and a grayish tan sludge on the bottom. I tried making a second batch thinking I added part c too fast but I got the same result. I thought the water I distilled might have been contaminated so I tried again with store bought distilled water and it happened again. Frustrated, I ordered all new chemicals from Artcraft and tried again today - same result. If I let the sensitizer sit for 24 hours then filter it I get a clear liquid which lacks contrast and is rather thin density wise. Anybody know what's going on here?

My formula is:

Part A
9 gm - Ferric Ammonium Citrate
33 ml - distilled water

Part B
1.5 gm - Tartaric Acid
33 ml - distilled water

Part C
3.8 gm - Silver Nitrate
33 ml - distilled water

Mix parts a, b, & c separately. Add part b to part a slowly with constant stirring. Add part C very slowly with constant stirring.

Any help would be greatly appreciated.

Best to all - Scott