Oil black treatment..... very nice - Page 3
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  1. #41
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    I had to make a new unobtainable safety for a no name .410 O/U shotgun so I thought I would try the boil in oil method of coloring. It was hard to get an even heat on the part and you can see the different colors on the finished product. I actually like the colors so I didn’t keep heating and quenching. I would have normally used a cold bluing gun product, but this is quite presentable for small parts. That's paper towel fuzz on the finished part.





    Some of you know I’m a gunsmith so I am familiar with black oxide blueing. Some call it hot salts blueing or hot dip, but it’s all the same thing. Its 3 components are sodium hydroxide, (caustic soda flakes, lye), sodium nitrate, and sodium nitrite. It holds up well to being handled, but still needs to be oiled to last.
    All black oxide finishes are applied exactly the same way. The way a part comes out of the blueing tank is all dependant on how it is polished. Polishing is 98% of a well done black oxide finish. If the part is bead blasted and blued it will be a matte finish. If the steel is polished to look like chrome and blued, it will be black with a hint of deep blue, mirror finish.
    Here is a picture of one of the worst polishing jobs I have ever seen. This Colt 1911 is/was on a gun auction site for something like $2,200. I wouldn’t give you $200 for it. Every sharp corner, straight line, or flat surface has been buffed on a wheel to within an inch of its life. I’m sure they had to re-stamp the lettering because it must have been almost removed. I guarantee if you sighted down the flat on the side of the slide, it will be rippled like a wash board. It also should not be polished as bright as it was.
    I don’t know what a mirror polish and heated/dipped in oil finish would look like. Probably lose some of its shine.


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  3. #42
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    One day all iron or steel that was exposed and not oil coated in my shop rusted.
    A source of heat that keeps the steel parts above ambient temperature will stop that from my experience, I keep many machine tools in the hangar and try to have a lightbulb under machines that are tarped. Some have an old garage sale electric blanket on low that is between the machine and the tarp. I conclude that temperature changes can allow condensation to form on the surfaces and it is surprising, as you said, how fast that awful sickly reddish coating forms.
    I have to go today and treat the struts again, and this time I'll try the WD40 specialist, and hope to report back in a couple of weeks.
    Ideally I'd like to stop the rusting process for an extended time to my satisfaction and then paint it with a good paint. What I didn't say before is that I'd previously gone through the whole process of sanding down to bare metal, then applying Ospho (Diluted phosphoric acid), then carding that and re applying Ospho, lightly carding again and painted with POR25, which is supposed to be the end all for rusting. 6 months later there is the rusting under that!

    The airplane is a classic from 1946 and it's my third one by that builder, so you can understand why rust is such a nightmare for me.

  4. #43
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    Here is a picture of one of the worst polishing jobs I have ever seen.
    Had they gone a bit farther they could have called it "Melted" and sold it for more.

  5. #44
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    If you think that is bad, an artist friend was commissioned to make a bronze head of a local business leader. She did a careful wax and had it lost wax cast by a foundry that was supposed to know what they were doing. One of their clowns proudly presented her the casting with all the fine detail buffed away. She had to do the whole thing over.

    Bill

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