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Thread: Bluing

  1. #1
    Join Date
    Aug 2008
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    Charlestown NSW
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    Default Bluing

    Ken
    It would seem that the book gremlins have visited. I've just spent the last 30 mins or so looking for my blueing book. I've seen it recently but of course now I can't find it.
    Anyway I'll try and remember the recipe that I have used. This particular one wasn't printed in the book but was given to me by a work mate back in the 80's. I just had it written down on a bit of paper in the book.

    I haven't done this for at least 10 years so I can't promise that I remember it correctly. I can't guarantee that the process below is entirely correct.
    The last time I did it, we did it at work to reblue a lot of small parts of one of the student demo rigs.

    Also these chemicals are nasty if handled incorrectly so
    USE AT YOUR OWN RISK.

    you need a good steel or cast iron container (not alloy) and something to heat it on. One of those 2 or 3 ring burners you can buy from BBQ's galore is perfect. Also some steel bars that you can lay across the top to hang your parts from
    You need some 50% caustic soda solution. (we bought a 20 litre drum from a chemical supply company. Don't know how easy it would be to buy in larger quantities these days. Obviously the quantity depends on how big the parts you want to blue are)

    you also need some ammonium nitrate. (again when we bought it last, it was readily available but not anymore after all the terrorist activiety. maybe if you know a farmer?)

    If you want a good finish your steel parts should be polished. The blueing will accentuate any marks on the surface.

    Your parts have to TOTALLY free of any oil or grease. give them a good clean in a solvent like acetone or similar. After that don't touch them with your bare fingers, use clean rubber gloves.


    Now the recipe as I remember it is. (its not real critical)

    to about 9 litres of 50% caustic you add about a 375 gram margarine container of ammonium nitrate. (told you its not real critical, you might have to play around with quantities )
    NOTE this will release a lot of ammonia, do it outside and maybe warn your neighbours. I think the solution gets fairly warm as the reaction takes place so your container should be suitable. ie don't use an el cheapo plastic bucket. a good heavy duty one should be ok, but don't hold me to that.

    Once it has finished releasing the ammonia, the solution is ready.
    Now you put some in your steel pot over the heat source and bring to the boil. A steel lid is handy as well.
    (again, best to do it outside as the fumes are quite strong and any metal they settle out on will be corroded.)

    once its boiling nicely hang you parts, using steel wire (not zinc plated) into the solution. make sure they don't touch each other or anything else. you will have to come up with a method of attaching them to the wire so that the wire doesn't cover any part of the part that will be visible once the part is in use.
    It would be a good idea to play around with the recipe on some scrap before you start on the good stuff.

    Keep the solution boiling with a lid on the pot.(this just condenses a lot of the steam and it drops back into the pot. The solution will thicken up eventually and can even go hard once it cools down, its pretty much useless then)

    You can see how the colour is progressing by taking a part out and having a look. if its not dark enough put it back in for longer.
    Once its the colour you want take it out and give it a good wash in hot water. You need to remove all of the solution. hang the parts up to dry , once dry dunk them in some clean oil and then wipe clean.

    That last bit is a bit more hazzy to me than the rest so it would be a good idea to try a few different things and or research a bit more. ie maybe using warm oil etc.
    Don't forget these chemicals are quite dangerous so make sure you use the proper protective gear.

    Don't let the solution or fumes touch anything alloy that you want to keep.

    Once its cooled down the spent solution makes a good drain cleaner. (Draino is mainly caustic)

    the book I have is this one

    [ame="http://www.amazon.com/Firearm-Blueing-Browning-R-Angier/dp/0811706109"]Amazon.com: Firearm Blueing and Browning: R. H. Angier: Books[/ame]

    it has some interesting recipes in it but a lot of the ingredients are listed under their old names which can mean a bit of detective work to find out what they are. I've never actually tried any of these recipes.

    I can't state enough that I'm not 100% certain I have remembered this correctly so please take care if you decide to try this.
    I have some parts that I did over 20 years ago using this method and most of them as still as good now as when I did them.

    There are also some commercial cold blueing kits available that are supposed to be good but I have no experience with any of them.
    You would also get some info off some of the gunsmithing forums in the US I would think. I don't read any gunsmithing forums but as the US is the land of guns I'm sure there will be some forums relating to them.

    hope this helps

    regards

    bollie7
    Last edited by bollie7; 28th Apr 2009 at 10:20 PM. Reason: typos

  2. #2
    Join Date
    Aug 2008
    Location
    Charlestown NSW
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    65
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    Default

    arose62
    After re reading my last post about the blueing, I realised its hijacking your thread. Sorry, that wasn't my intention. Perhaps a moderator can move that post if they think it is necessary.

    regards
    bollie7

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