A spotting blue recipe

[MuellerNick]

Hi!

Today, it once more came to my mind to give it a try testing my own spotting blue recipe. Just when I decided to hop into the train heading to Munich, I thought why not first phone the manufacturer of the pigments. So I had an very interesting talk to the doctor of chemistry (boss of that company). We talked about particle sizes. His anorganic blue pigments are 1 µm in size. Organic pigments are much bigger.
So I was prepared to actually buy the stuff:
100 g of Milori blue (Berlin blue, Prussian blue) and some polyglykol.

Some mixing at home and ... success! It is a bit complicated to apply to the granite plate and needs constant refreshing, even worse than Dykem. But it is at least as good as all the spotting blues I have tried, regarding how easy it is to read.

There is even better news:
The ingredients are available in the USofA, they do have a shop there. Only the polyglykol is way more expensive than here.
The company is Kremer-Pigmente. (www.kremerpigments.com).
The direct link to the pigment.
The direct link to polyglykol

You might try other oils. The polyglykol is sold in 1 l bottles, way too much! Is anti-freeze an alternative?

Simply add the polyglykol to the pigment and thoroughly massage it until it really is mixed well. Works best on a glass plate. Pay attention not to add too much polyglykol. The better you mix it, the thinner the stuff gets. You might end having to add some pigments. My consistency was that it just didn't drip off of an screwdriver. Let it sit for an hour (I got impatient) and then ... have fun!

A big advantage is, that it is really easy to get off of your hands. Just water and soap, no wire brush required.

I'll try now for the yellow ...


Nick

[Your Old Dog]

Sorry late post, just back from vacation.


I thought the big ingrediant in the blueing stuff was potassium permanganate of which a chemist gave me two 10oz bottles. Turns out it makes a nice die for maple gun stocks turning them a beautiful fake aged color.

[MuellerNick]

I thought the big ingrediant in the blueing stuff was potassium permanganate

That is violet in color and won't go off of your fingers for weeks.

Nick

[Circlip]

and it won't go off your clothes FOREVER.

Regards Ian.

Wonder what you can mix the blue powder with to get the "Dry" marking fluid - similar to the box markers? Obviously an evaporative but which binder.?

[PeteF]

Nick isn't linseed oil used as a base in those spotting blues?

[MuellerNick]

Nick isn't linseed oil used as a base in those spotting blues?

That would end in a paint. It dries!


Nick

[TGTool]

IIRC it's boiled linseed oil that will polymerize over time but raw linseed oil won't harden up. Of course that still gets you back to the stuff that has to be scrubbed up to get clean rather than the straightforward water wash up that Nick was after.

I don't know enough about chemistry to know if there would be other water based combinations that would work and/or be easier to acquire. Water with a few drops of detergent for a surfactant might get something but would dry out on the surface which might or might not be a problem. It might still transfer satisfactorily when dry, or it might be misted from time to time with a spray bottle to keep it active.

This really opens up a great area for speculation and experimentation. Thanks for getting that started.

[gwilson]

1: Raw linseed oil WILL harden. Just takes longer. Used it for many years.

2: Potassium permanganate (KMNO4) is purple,but turns brown on wood. I use it all the time for antique repair blending. Be warned,though,it will fade if you put anything like a drying oil over it.

3: It WILL explode if you expose the crystals to turpentine. It is FULL of oxygen,and so is turpentine. BE CAREFUL.

4. KMNO4 IS POISON. Use nitrile gloves and keep it off your hands. A good dose of it on your hands will harden the outer skin into a hard,leathery layer that can only be worn off,or maybe helped by sanding it off.

5. KMNO4 is not easy to get since it is an explosive ingredient. We had to go through special channels to get it when I wanted some at Colonial Williamsburg. Since we were a museum,we were able to get stuff like nitric acid,etc.,not publicly available these days.

Old dog,were those 10 oz. bottles OLD stock? the chemist risked getting in big trouble giving those to you. Wonder if he knew it was a restricted material now? Years ago,Boy Scouts used it on poison ivy!!

[John Garner]

The old-fashion Prussian Blue paste from the paint store that a number of old texts recommend as a spotting compound was, in paint-store lingo, a "color mixed in oil", and most often the oil was unboiled linseed oil. The unboiled linseed oil, especially when spread to a thin layer, will most assuredly oxidize to a gum in a few hours, and then to a solid.

In the late 1960s I was taught to mix my own spotting compound from pigment powder (white lead, Prussian blue, red lead, carbon black, or something-or-another-that-I've-forgotten yellow) and USP Heavy Mineral Oil or USP White Petrolatum to create a spotting compound that would take weeks or months as room temperature to oxidize. Forrest Addy has mentioned several times that he mixes his own spotting compound using the powdered pigment and short-fiber bearing grease.

It should go without saying, but compounds mixed with mineral oil, petrolatum, or bearing grease aren't water-washable.

[PeteF]

Raw linseed oil does indeed harden, but it takes a long time, and sure as heck won't harden in a scraping session! Typically hardeners are added to linseed oil to create "boiled" linseed oil, incidentally one of the reasons that boiled linseed oil shouldn't be considered "food safe", unlike raw linseed oil.

[gwilson]

Why use any linseed oil? Use mineral oil. Then,you won't have ANY problem.

You could find your carefully made blue getting a scum on it in the can. WHY,WHY,WHY,use linseed oil? Is it supposed to be magic,or something??????

It seems rather pointless to go just looking for trouble,when mineral oil is freely available.

[MichaelP]

KMNO4 IS POISON.

Not really (although anything can be poisonous in certain doses). I wouldn't eat the crystals though.

KMNO4 is not easy to get since it is an explosive ingredient.

The easiest way is to visit your local ACE Hardware and find potassium permanganate on the shelf where it's sold as an iron water filter recharging agent. About $10 per pound if I remember correctly.

[PeteF]

Why use any linseed oil? Use mineral oil. Then,you won't have ANY problem.

You could find your carefully made blue getting a scum on it in the can. WHY,WHY,WHY,use linseed oil? Is it supposed to be magic,or something??????

It seems rather pointless to go just looking for trouble,when mineral oil is freely available.

Actually my original post was a question, hence the question mark at the end of the sentence. I vaguely seemed to recall seeing somewhere that linseed oil was used as a base, at least in traditional formulae, and those foggy brain cells seem to be confirmed by John. Why it was used I have absolutely no idea.

[gwilson]

I'll check out the Ace hardware thing. Just TRY to buy KMNO4 from a chemical supply house. Are you sure it is pure?

I suggest you google the stuff. It can be FATAL if ingested,and is listed as a severe health hazard. You can use it as a medicine,but it has to be used correctly.However,apparently you can buy it from the chemical supply among the listed things. Our purchasing secretary told me it was restricted.

[wierdscience]

Buy dry pigment in the color you want,make up a simple ball mill and mill it to the particle size you want.Just be careful milling organics,too fine and they spontaneously combust when you pull the lid off the mill,don't ask how I know

As a carrier I would try vaseline,easily removed with mineral spirits.