Life of Cyanotype Chemistry?

bjorke · Jan 2, 2005

We have a batch of chemicals that have been shelved for about a year. Are they worth keeping at this point?

T.I.A.,

donbga · Jan 2, 2005

bjorke said:
We have a batch of chemicals that have been shelved for about a year. Are they worth keeping at this point?

T.I.A.,

Most likely they will be fine. Mix 'em up and give it a whirl.

Don Bryant

127 · Jan 3, 2005

Dry they should be fine. Once you've made the solutions one part keeps for a year or so, while the other goes funny after about a month (I forget which is which, but it's VERY obvious - looks like stuff growing in it).

Once you've mixed the two parts they keep a day or two.

Ian

Ole · Jan 3, 2005

My solutions are both fine after 8 months - nothing "gone funny" at all. Maybe the smidgeon of oxalic acid I added to each works as a preserving agent?

Joe Lipka · Jan 3, 2005

Luddite, Ha! You are much more technically adanced than that! Oxalic Acid works just fine to kill that funky stuff that grows in one of the solutions.

I ran into the same problem, but the stuff that was growing inside the bottle was able to keep me from opening the bottle and disposing of the stuff.

We are now in our second year of a truce.

Aggie · Jan 3, 2005

Similar question about Van Dyke solution once mixed. Will it keep for very long? (Don't laugh) mine is just over 3 years old. It's well aged

hermit · Jan 3, 2005

I am using cyanotype solutions now 13 months old with no problems what so ever.

donbga · Jan 3, 2005

127 said:
Dry they should be fine. Once you've made the solutions one part keeps for a year or so, while the other goes funny after about a month (I forget which is which, but it's VERY obvious - looks like stuff growing in it).

Once you've mixed the two parts they keep a day or two.

Ian

I've never found this to be true. Mixed and stored properly they will last a long time. Store in dark glass jugs. Usually the biggest problem will be mold growth in Part A which can be eliminated with the addition of a few drops of a 100% solution of thymol.

Lately I've been using a 1/2 liter mix made over a year ago for the cyan layer of tri-colored gums.

Don Bryant

donbga · Jan 3, 2005

Aggie said:
Similar question about Van Dyke solution once mixed. Will it keep for very long? (Don't laugh) mine is just over 3 years old. It's well aged

Aggie,

I usually use my solutions of VDB quicker than that but I've found that sometimes an older VDB mix just seems to peter out. The best test is to try it and see. Bad VDB solutions print gray and flat, if it comes out red-brown you are okay. VDB is so inexpensive though that losing a small mix to age doesn't hurt the pocket book too much.

Don Bryant

Life of Cyanotype Chemistry?

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