Age Limits on Alt Chemicals

[Robert Ley]

Hello,

I am getting back into some Alt printing after a 5-6 year hiatus due to some health issues and life. I am primarily interested in Gum, Cyanotype and Van Dyke Brown VDB I have my mixed 10% potassium dichromate, which dates back maybe 8-10 years that I think and have been told will be still good. I have both regular A&B Cyanotype that I mixed from chemicals that I have and would be easy enough to mix fresh and I might do that anyway. I also have a small 250cc bottle of Ware's New Cyanotype, mixed in 2016, that I could probably remix but would rather not.

My big question is I have two bottles of VDB that dates back to 2016, so coming up to 7 years and the other about 2-3 years older. When I looked at the bottles a couple of months ago I noticed what I thought was mold in the (dark brown) bottles. I decided to do a quick filter with a mesh filter funnel and got what looked like silver flakes. Other than the flakes the solution is free of any other sediment. I would like to try to use these chemicals as silver nitrate is expensive.

I know I could just do some testing, but at my advanced age I'd just prefer to avoid as many rabbit holes as I can. I have already tested my main Gum pigments and have settled on 6-7 minutes with my homemade UV box. I could also easily test my Cyanotype as that is only water for developing, but the VDB requires more chemicals and time.

At this point I can either forge ahead on a Gum Project or figure out my Cyanotype and VDB chems and times.

I have had some success with my printing in the past, albeit with X-ray copy film and graphic arts film in the darkroom. I got into making digital negatives in my previous Alt printing life, but I never used curves so I need to learn to use curves and and I'll be posting on that in a future thread. Photoshop has changed a lot since I used it so I am starting to relearn Photoshop.

Any insights that you could impart on this old codger would be appreciated and I look forward to hearing from other practitioners of the Dark Arts.

 

[Bronson Dugnutt]

Part A of a traditional cyanotype/VDB solution (Ferric Ammonium Citrate) generally isn't stable long-term in solution. The dry powder itself isn't particularly shelf stable unless you can tightly control oxygen & moisture ingress.

The silver nitrate solution used in VDB is shelf stable if mixed in distilled water as is the Part B Ferricyanide solution used in cyanotype.

 

[Robert Ley]

Thanks for the lightning fast response. I routinely mix all my photo chemicals in distilled water and that is good to know about the VDB. Just checked my Ferric Ammonium Citrate (Green) and it is a hard as a rock lump in the bottom of the container so it looks like I will need to reorder, but I will order much smaller quantity. I will have to be more careful with storage of the this chemical.
Thanks for your help tonight!
Robert

 

[koraks]

I never had much luck keeping mixed VDB solution around. It would always silver out in a relatively short period of time and leave me with anemic prints and problems. Sounds like yours hasn't fared much better.

Btw, when I noticed that VDB solution is not very stable, I decided to just mix it fresh, as needed, on a per-print basis. This has always worked perfectly for me, using just three stock concentrates (silver nitrate, ferric ammonium citrate and tartaric acid). These are quite stable; the ferric ammonium citrate will ultimately go bad (signified by a color change from green to brown) and tends to grow mold pretty quickly (this can be filtered out and doesn't seem to hurt any). The silver nitrate and tartaric acid solutions are stable. I use the following concentrations:
Silver nitrate: 11%
Ferric ammonium citrate: 20%
Tartaric acid: 8% (but it's not critical; 10% will work just fine as well)
I measure out the solution by counting droplets from a pipette. The ratio is: 4 drops of silver nitrate to 5 drops of FAC to 2 drops of tartaric acid. I find this amount is sufficient to brush coat a 5x7" area on a moderately absorbent paper. Scale up as desired.
When adding the silver nitrate to the FAC or vice versa, a white precipitate results. This is cleared once the tartaric acid is mixed in.
The solution does not need to 'ripen', contrary to what many sources say. It's ready to go immediately.

There are two main advantages to this approach. Firstly, the solutions don't go bad as easily and you're never left with a bottle of bad or doubtful VDB sensitizer. Secondly, the silver nitrate and FAC solutions can also be used for other purposes, such as salted paper and classic cyanotype.

mixed 10% potassium dichromate, which dates back maybe 8-10 years that I think and have been told will be still good.

Yeah, dichromate is very stable, also in solution.
It might be of interest to you that there's a new product coming along that acts as an alternative for gum bichromate, but it's far less toxic and probably easier to use, too. It's called 'printmakers friend' and it's expected to be available by the end of this year or early 2024. https://printmakersfriend.com/ There's something similar (or probably, identical) called 'zerochrome': https://www.alternativephotography.com/zerochrome-sbq-colloid-printing/
It's a little different in a number of ways from 'real' gum bichromate, but I don't think it'll be possible to distinguish the 'real' ones from the new stuff (if done properly) without extensive chemical analysis.

 

[Robert Ley]

Koraks,
Thanks for your reply about the VDB. Your technique for mixing VDB sounds good and I think that I will give it a try. My FAC has gone bad and I'm waiting for a fresh batch from Artcraft. I have also ordered some 100ml dropper bottles to keep the chemicals. My tartaric acid seems fine and I have a supply of silver nitrate that I assume is still good.
Where did you get your information on the dropper method for VDB as I have never seen this technique before?
Thanks again and I must say that I have seen and enjoyed your very knowledgeable posts in the past.
Robert

 

[koraks]

Where did you get your information on the dropper method for VDB as I have never seen this technique before?

I made it up I wasn't entirely happy with the methods that I read about online, so I worked out the concentrations of the different constituents in the final mix and took it from there. I chose the concentrations of the stock solutions somewhat arbitrarily, but the 11% silver nitrate was based on the silver nitrate concentration I was using for salted paper at the time, so that made sense to me at least.

Thanks again and I must say that I have seen and enjoyed your very knowledgeable posts in the past.

That's really nice to hear, thanks

 

[Rolleiflexible]

I will add only that silver nitrate is stable in solution, but if you have questions about yours, contact Mike Jacobson at Artcraft Chemicals in Altamont, NY (near Schenectady). Mike is a primary source for silver nitrate and knows more about it than just about anybody else.

Artcraftchemicals

Artcraftchemicals

artcraftchemicals.com

Mike can fix you up with your other needs for VDB and cyanotypes as well.

 

[Robert Ley]

I will add only that silver nitrate is stable in solution, but if you have questions about yours, contact Mike Jacobson at Artcraft Chemicals in Altamont, NY (near Schenectady). Mike is a primary source for silver nitrate and knows more about it than just about anybody else.

Artcraftchemicals

Artcraftchemicals

artcraftchemicals.com

Mike can fix you up with your other needs for VDB and cyanotypes as well.

I just ordered some 120ml dropper bottles and 250gms of PAC from ArtCraft. Rolleiflexible, thanks for the contact info on ArtCraft and I have been using them for chemicals for quite a few years.

 

[Robert Ley]

I made it up I wasn't entirely happy with the methods that I read about online, so I worked out the concentrations of the different constituents in the final mix and took it from there. I chose the concentrations of the stock solutions somewhat arbitrarily, but the 11% silver nitrate was based on the silver nitrate concentration I was using for salted paper at the time, so that made sense to me at least.

That is way cool and thanks for doing the math for us I have decided to use your technique for VDB and will let you know how it works out for me.

 

[koraks]

I'd be very pleased to hear if it works as well for as it does for me! Thanks in advance