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A spotting blue recipe

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  • gwilson
    replied
    I suggest you guys use KMNO4 for whatever you want. No sympathy here when you get into trouble. It can be used in medicine by a doctor who knows how to administer it. If you other guys bothered to Google and read,you would have seen that it is a Health Hazard 3,and can be fatal. If you do not think it is an explosive ingredient,try remotely dumping some into GENUINE turpentine(not the crap commonly sold now). It id loaded with oxygen.

    Health hazard 3= short exposure can lead to serious temporary or residual injury. I'm sure you guys whose minds are already made up don't want to be confused with FACTS,and are too lazy to research it.
    Last edited by gwilson; 08-15-2010, 09:41 PM.

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  • Guest's Avatar
    Guest replied
    Mixing your own spotting compound is probably fun but other than that I can't see any reason to do so.
    I have three different brands here and they all do some thing better than the other one. There are differences, it's not just some ole blue.
    For me, the Diamant brand (German) is better in the beginning, for fine work the Dykem is better to read but not as forgiving in how you apply it to the master. Also Dykem transfers better from CI to CI.

    My question for Nick though: what's the advantage of Polyethylene glycol over mineral oil?
    Until now, it is only way easier to get off your fingers. I also have the impression, that it reacts better when you rub the work longer against the master. Might be, that it can be easier pushed off of the high spots.

    I'll have to make a real scraping task with my mixture.

    I think, I have more pigments compared to the others, but I don't know by numbers.


    Nick

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  • lazlo
    replied
    Originally posted by gwilson
    KMNO4 IS POISON.
    It's a strong oxidizing agent, but it's not poisonous. Potassium permanganate is used to disinfect drinking water and swimming pools.

    KMNO4 is not easy to get since it is an explosive ingredient.
    It's an oxidizer, not an explosive, and is available at any pool supply store

    You can also get reagent-grade potassium permanganate at any chemical supply company without a license, and it's dirt cheap on Ebay:
    Potassium Permanganate 98% One Pound

    Potassium permanganate has the density of 2.7. It is a dark purple, crystalline solid which is soluble in water, acetone and methanol. It's uses include - disinfectant (used in cleaning fish tanks), deodorizer, bleach, dye, tanning, reagent in analytical chemistry, medicine (antiseptic), manufacture of organic chemicals and purification of water and air. This material is shipped in compliance with USPS Publication 52 guidelines, Section 5A, Appendix A, as an ORM-D, which will be shipped USPS Ground (Parcel Post).

    My question for Nick though: what's the advantage of Polyethylene glycol over mineral oil?
    Last edited by lazlo; 08-15-2010, 11:39 AM.

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  • Tony Ennis
    replied
    As far as wood finishes are concerned, "boiled linseed oil" generally contains no linseed oil at all. The name is more of a style than a promise of content.

    I like using it on woodworking projects.

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  • willmac
    replied
    Mixing your own spotting compound is probably fun but other than that I can't see any reason to do so. A tube or tin of commercial spotting compound lasts a good long time and it isn't that expensive. Or am I missing some vital advantage of home made stuff?

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  • MichaelP
    replied
    Originally posted by gwilson
    Are you sure it is pure?
    It's pure enough to be used not only as a dye, but even as a medicine. Just regular potassium permanganate crystals without any intentional additives. You can use it for antique repair without any hesitation.

    I suggest you google the stuff.
    I don't need to. I used it very extensively to treat patients (no, I didn't buy it in hardware stores ).
    Last edited by MichaelP; 08-15-2010, 02:32 AM.

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  • wierdscience
    replied
    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.

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  • gwilson
    replied
    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.
    Last edited by gwilson; 08-14-2010, 10:38 PM.

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  • Guest's Avatar
    Guest replied
    Originally posted by 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.
    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.

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  • MichaelP
    replied
    Originally posted by gwilson
    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.

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  • gwilson
    replied
    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.
    Last edited by gwilson; 08-14-2010, 08:54 PM.

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  • Guest's Avatar
    Guest replied
    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.

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  • John Garner
    replied
    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.
    Last edited by John Garner; 08-14-2010, 01:28 PM.

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  • gwilson
    replied
    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!!
    Last edited by gwilson; 08-14-2010, 12:48 PM.

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  • TGTool
    replied
    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.

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