Bad Van Dyke?

[alec4444]

A new meaning to "BVD".....or not? My solution seems to separate - rather quickly.... Is this normal? If no, what might I have done wrong? (See attached)

Thanks!
--A

[katie cooke]

Was it like that as you mixed it, or after?

If the former, you have to add the silver nitrate very slowly to the other parts, drop by drop, or it does separate.

[alec4444]

Thanks, Katie - after some digging, I read that on Photo.net. So I tried again, and mixed it far slower. Same thing.

That's when I pulled out an eye-dropper, and really did do it drop-by-drop. ...And? Same thing. Though the precipitate might actually be slightly finer.

The guy from photo.net said that it worked even with the precipitate, so before I'm out 36 grams of silver nitrate, I might just give it a go anyhow.

Can the paper dry overnight, or is it really only good for a couple hours? (That per Christopher James)

Ok, now off to the sink to wash my arms off, which feel like they're burning for no apparent reason..... No brown stain....perhaps it was the Tartaric acid? Such is life!

--A

[cyrus]

ph can have a really big effect in instigation of precipitation, as can any impurities (even oil or sweat from skin)

[alec4444]

So in terms of using it, is it "life threatening"? Anyone else still use the solution with the precipitate?

[Joe Smigiel]

Carefully stir it up and grab a small sample before it settles. Try adding some more tartaric acid to the small sample and see if the precipitate goes back into solution. Might salvage it.

I've never had a batch major separate like in your pic. There's something grossly wrong there. Check the tartaric acid amount again. Was the ferric ammonium citrate green or brown? Silver nitrate clear/white crystals or gray?

[katie cooke]

My first batch was mixed too quickly, and was cloudy, with floating specks in it (not pretty) but I used it anyway, just to see what it did. It created grainy, spotty prints that behaved very oddly.

Trying to think what else might be doing this, if it's still happening when you are doing drop by drop and stirring as you go...you're using distilled water? There's not chance any of the containers or stirrers might be contaminated with something else?

[Jim Noel]

I have never had the problem, but I mix everything on a magnetic mixer which does a superb job.