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Thread: which blueing?

  1. #1

    which blueing?

    what looks best and is also quite durable..

    a. hot blueing
    b. slow rust blueing
    c. cold blueing

    any thoughts?

  2. #2
    Cold blueing is the least durable and looks thin and blotchy compared to the other two.

    In terms of durability, both 'proper' blueing methods are about even (in my experience), whilst the hot blue normally looks a bit blacker than rust blue. Rust blue is a very time consuming process and so hot blue was developed to shorten that timescale, and almost universally used commercially unless it is contra-indicated (for example with soldered barrels).

    I like rust blue but that's probably because I like the process (don't like hot smelly tanks).

  3. #3
    Thanks Knot,

    Yeah, I'm starting to toy with the idea of rust blueing my rifle rather than hot blueing.

    do you know what the 'airing/humidifying' cupboard thing is they use to hang the parts in, and how do you build one? also, is the rust polished with a plastic bristle style wheel, felt or cloth? that is, before re-applying the next coat and hanging, again and again, etc. LOL...

    am I also right in thinking that with hot blueing you have to apply the blue in very even long strokes to avoid streaks, which makes blueing the receiver rails and internal areas tricky for an even finish, but with rust blueing you almost rub the chemical on, which means intricate areas are much more likely to come out with a smooth even finish?

  4. #4
    Excellent choice. Rust blueing is both magical and fully reversible - if you don't like the results, it is easily chemically removed and you can try again.

    You need to start with the metal in the right state - I always remove all the old blue with De-Ox and polish up (I find that going finer than about 320 gives uneven results and the process tends to give a nice satin finish rather than a highly polished one anyway). You will need to mask up any areas that you don't want blued - shellac or latex paint are good for this. You then need to degrease everything very thoroughly (I suggest acetone) and don't touch anything with your bare hands again - use disposable latex gloves.

    The next step is to accelerate the rusting process. You could just let it rust naturally but this would be a very slow process. Various solutions can be used - the easiest is to buy one premixed (you'll have to Google suggestions for this as I haven't used any) or make up your own (a variant on the old aqua fortis recipe below but be careful).

    Mix Nitric acid (@70% concentration) with Hydrochloric acid (@ 30% concentration) at a ratio of about 7 parts to 5 parts by volume.
    Very slowly add iron fillings over a day or so until they stop dissolving.
    Strain.
    Add the strained solution to 80 parts by volume of distilled water (find someone with a dehumidifier) - it is very important you add the solution to the water and not the other way round.
    This doesn't keep very well so don't make too much.
    Do everything involving the acids and the resultant solution outside and away from any metal that you want to keep.


    Sneaking some of your wife's cotton balls for removing makeup (not really dear if you are reading this) and holding them with a pair of tweezers, dip in the mixture and soak the surface of the metal - when repeating this subsequently, you should aim to coat the surface evenly but with as little as possible.

    Get a big black plastic bag (bin bag is fine) and put the metal inside with a tray of more distilled water. Seal with a wire tie or clip and if possible, put in the sun or otherwise put somewhere warm to create a nice humid atmosphere. Leave it for a day or so until it is nicely covered in red rust.

    Get a suitable container which is big enough to easily hold the part in question (you will need plenty of water in with the part), fill it with distilled water, and bring to a rolling boil. Carefully add the part and make sure it gets a good 10 minutes of actual boiling (a set of S/S barrels will soak up enough heat to take it well below boiling initially). Remove and drain.

    You should now have a finish on the metal which will probably be greyish to start with (but which will get deeper and more blue with subsequent repetitions) and a fairly roughish surface. You need to rub it down - the ideal is a carding wheel (a very fine almost hair-like wheel) but they are very difficult to find these days at a reasonable price in the UK, and so you will need to use 0000 wire wool - however, remembering that we are deathly afraid of oil and grease at this point, put your wire wool in a clean jam jar of acetone, give a good shaking and dry it before use to get rid of any contamination.


    Repeat the process - about six times is the right amount for barrels as too much more can cause pitting. If it isn't right at any point (for example oil/grease causing spotting), stop, strip it, and start again as it won't be covered up by subsequent coatings.

    Finally, when you are happy, finish with your favourite gun oil. The old way used to be soaking overnight in oil but i find that giving three saturation coats (preheat the oil to thin it by standing the oil container in hot water first) following each time by wrapping in an oil saturated cloth (sorry again dear) is fine.

    HTH
    Knots
    Last edited by Knottaclu; 14-03-2012 at 12:09.

  5. #5
    Caustic blue will retain polish, rust blue will look 'satin' as it etches the steel (hence no need to mirror polish).

  6. #6
    Quote Originally Posted by Knottaclu View Post
    Excellent choice. Rust blueing is both magical and fully reversible - if you don't like the results, it is easily chemically removed and you can try again.

    You need to start with the metal in the right state - I always remove all the old blue with De-Ox and polish up (I find that going finer than about 320 gives uneven results and the process tends to give a nice satin finish rather than a highly polished one anyway). You will need to mask up any areas that you don't want blued - shellac or latex paint are good for this. You then need to degrease everything very thoroughly (I suggest acetone) and don't touch anything with your bare hands again - use disposable latex gloves.

    The next step is to accelerate the rusting process. You could just let it rust naturally but this would be a very slow process. Various solutions can be used - the easiest is to buy one premixed (you'll have to Google suggestions for this as I haven't used any) or make up your own (a variant on the old aqua fortis recipe below but be careful).

    Mix Nitric acid (@70% concentration) with Hydrochloric acid (@ 30% concentration) at a ratio of about 7 parts to 5 parts by volume.
    Very slowly add iron fillings over a day or so until they stop dissolving.
    Strain.
    Add the strained solution to 80 parts by volume of distilled water (find someone with a dehumidifier) - it is very important you add the solution to the water and not the other way round.
    This doesn't keep very well so don't make too much.
    Do everything involving the acids and the resultant solution outside and away from any metal that you want to keep.


    Sneaking some of your wife's cotton balls for removing makeup (not really dear if you are reading this) and holding them with a pair of tweezers, dip in the mixture and soak the surface of the metal - when repeating this subsequently, you should aim to coat the surface evenly but with as little as possible.

    Get a big black plastic bag (bin bag is fine) and put the metal inside with a tray of more distilled water. Seal with a wire tie or clip and if possible, put in the sun or otherwise put somewhere warm to create a nice humid atmosphere. Leave it for a day or so until it is nicely covered in red rust.

    Get a suitable container which is big enough to easily hold the part in question (you will need plenty of water in with the part), fill it with distilled water, and bring to a rolling boil. Carefully add the part and make sure it gets a good 10 minutes of actual boiling (a set of S/S barrels will soak up enough heat to take it well below boiling initially). Remove and drain.

    You should now have a finish on the metal which will probably be greyish to start with (but which will get deeper and more blue with subsequent repetitions) and a fairly roughish surface. You need to rub it down - the ideal is a carding wheel (a very fine almost hair-like wheel) but they are very difficult to find these days at a reasonable price in the UK, and so you will need to use 0000 wire wool - however, remembering that we are deathly afraid of oil and grease at this point, put your wire wool in a clean jam jar of acetone, give a good shaking and dry it before use to get rid of any contamination.


    Repeat the process - about six times is the right amount for barrels as too much more can cause pitting. If it isn't right at any point (for example oil/grease causing spotting), stop, strip it, and start again as it won't be covered up by subsequent coatings.

    Finally, when you are happy, finish with your favourite gun oil. The old way used to be soaking overnight in oil but i find that giving three saturation coats (preheat the oil to thin it by standing the oil container in hot water first) following each time by wrapping in an oil saturated cloth (sorry again dear) is fine.

    HTH
    Knots
    love the idea of this - will go that route, Bewsher will also be happy that I won't be spending days in his backyard with his new hot blueing tanks! LOL.

    Knotta...thank you VERY much for your help.

    P

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