Formalin and such

[kb3lms]

I've been reading posts on APUG for some time now and I am absolutely fascinated by the idea of mixing up my own E-6 Chemistry. (Whether I ever will or not remains to be seen ) In various threads it is said that E-6 still requires formalin in the process. The Formulary doesn't list formalin, but a quick Google search comes up a 37% Aquarium solution called Formalin-MS, such as Dead Link Removed. Can you use this stuff, or similar, as the formalin? Is this true for other things like KI, Acetic Acid (Vinegar) and so on? Some of this stuff is really expensive from chemical houses but much less costly from the "grocery store" so I was wondering. Thanks!

 

[Photo Engineer]

Well, I would have to see the MSDS to check if there are other ingredients present, but it looks ok from a superficial glance. However, you might wish to note that it is backordered. Out of Stock.... Lets hope that they can get more.

Most chemicals that you use should be Photo Grade or some such. At least pure enough to prevent problems. And, the purity requirements are higher for color than for B&W. You can use white vinegar for Acetic Acid, as long as you dilute it properly. There are some grocery store items that I would not recommend such as CD3 or Citrazinic acid.

PE

 

[kb3lms]

Here's the info from the MSDS. Looks like water, formaldehyde and some alcohol. And you can really get CD-3 at grocery stores?

Product Identity: Formalin-MS
Section I. Hazardous Ingredients / Identity Information
Water 47 - 53.5% CAS #: 7732-18-5
Formaldehyde 36.5 – 38% CAS #: 50-00-0
Methyl Alcohol 10 – 15% CAS #: 67-56-1

Section II. Physical/Chemical Characteristics
Boiling Point: 98°C (208.4°F)
Specific Gravity (H20 = 1): 1.08
Vapor Pressure (mm Hg.): 2.4 kPa (@ 20°C)
Melting Point: -15°C (5°F)
Vapor Density (Air = 1): 1.03
Solubility in water: Easily soluble
Appearance and Odor: Clear Colorless liquid with strong odor. Pungent.

 

[Athiril]

Ive seen 37% on ebay pretty cheaply... not at the moment though it seems.

PE: I'm curious as to where to get citrazinic acid from?

 

[Photo Engineer]

The MSDS is ok then for use in E6 and C41 processes.

PE

 

[kb3lms]

BTW, and you all probably know this already, Potassium Hydroquinone monosulfonate is also known as Hydroquinone Sulfonic Acid (CAS 021799-87-1) thanks to a Kodak hazardous label sheet. You get it at Cole-Parmer (http://www.coleparmer.com/1/1/37969-hydroquinone-sulfonic-acid-potassium-salt-tech-5g.html). Potassium Hydroquinone monosulfonate doesn't come up anywhere. Unless you are going to tell me this would not work . (I always think I am the last person in the world to find this stuff out!)

 

[Photo Engineer]

Look at purity and price / gram.

PE

 

[kb3lms]

PE, please tell me what to look for to find purity because I am not anything resembling a chemist. I freely admit to dimly remembering just enough from high school chemistry to maybe be dangerous. Is it in the MSDS? I do see something in the listing that says it is "Technical Grade" for "manufacturing and general lab use". In other words are you telling that this chemical would not work or not work well?

Cost of 100 g is $21.20 plus shipping/hazmat. Is there is a better place to purchase this stuff? The same place sells the Citrazinic Acid which the other poster was looking for.

 

[Photo Engineer]

Check purity of HQMSK salt. It is often 85% or less.

As for the others, you should get Analytical or Reagent grade. The Formulary supplies mostly Photograde which is just right for us.

And, this undertaking of yours is typical of the problems with being non-chemists. It is a problem with understanding the fundamental problems. Are you sure you want to go on?



PE

 

[Gerald C Koch]

Here's the info from the MSDS. Looks like water, formaldehyde and some alcohol. And you can really get CD-3 at grocery stores?

Product Identity: Formalin-MS
Section I. Hazardous Ingredients / Identity Information
Water 47 - 53.5% CAS #: 7732-18-5
Formaldehyde 36.5 – 38% CAS #: 50-00-0
Methyl Alcohol 10 – 15% CAS #: 67-56-1

The methyl alcohol is used as a preservative. Formaldehyde is a gas that is very soluble in water. However the water solution will slowly polymerize to a water insoluble chemical called paraformaldehyde. The methyl alcohol is used to slow this process. It is in all formalin preparations. Nothing to worry about it will work fine. Avoid breathing the fumes of the concentrated solution.

 

[kb3lms]

I'm not a chemist but I play one on TV?

Well, my collection of film in the freezer in my garage would answer that question!

My profession is software engineer (which probably explains why I like film) and I used to work with a now retired electrical engineer who always accused me of oversimplifying anything electronic so why would this be any different. Guess I am making up for the 11 years I worked at EK (left in 1993) and shot next to no film - stupid. But that was a different time and story. Seriously, I will start with mixing B&W chems before moving into E-6 or C-41.

So as long as you guys tolerate my learning curve, I go forth with my daughter's chemistry book in hand!

 

[Photo Engineer]

I am here to help.

PE