Steel Parts Bluing

Post by shazhib

Folks,

I don't know if this is a right topic to post here, but could you kindly share your wisdom on "how to blue steel parts".

This weekend, I tried to blue my MGC Thompson drum magazine, outcome was absolutely "les miserable". I followed usual "must to do" thing as:

1) removed rust by sand paper, liquid and gel rust remover
2) mag became silver, looks very clean
3) wash out any oil/grease with dish soap ("neutral" type, don't know how to say in English, which is between acid and alkaline)
4) pour Birchwood's Super Blue into a "zip-lock" bag and soak the bag into almost boiled water to warm up the bluing liquid
5) dump mag into "zip-lock"
6) move around the mag inside the bag, took out, gently brushed with brass wire brush and put the mag back into the bag
7) did "6)" for couple times, take the mag out of the bag and placed onto a news paper in order to let it dry
next day, mag is kind of black, but found lot of deposit kind black thing on surface of the mag . If I wipe a surface of the mag, those deposit easily fell off, but found the surface is not blued, I still can see dull metal surface (it looks like put the mag inside sheet stocking).

I've tried blueing steel parts many times in a past, but never came to the point I statisfied. Could somebody can advise me on this? Here is some question I have.

a) do I need to make mag complete dry after degreasing, before putting into "zip-lock"?
b) do I need to keep removing black deposit thing during a process of brushing the mage in process "6)"? Do I suppose to just brush off or can I rinse with water?
c) for bigger surface item, like mags, which of "dumping" or "painting"
would give me a better result?
d) what I should be doing before I leave the mag to dry or finishing out for the day?

Any suggestion would be highly appreciate.

Post by Spencerman

Personally I have always used Bisley Gun Blue, it is a kind of gel that you 'paint' on. Preparation is everything, and getting it nice and clean to start with is the key. Sounds like you are doing that fine. Next, with the Bisley stuff anyway, apply it evenly with a brush (I have never soaked a gun but assume that the following would apply). Are you going for a warm blue or a cold blue finnish? For a warm blue you should only leave the blueing solution on for a bout 30 seconds at a time, and repeat the process a couple of times. For a cold blue then you need to at least double this and repeat a few extra times. Rinse the blue solution off, and make sure to thoroughly dry. Some of the blue will come off onto your rag, and will have a dull black appearance. Once you have a nice covering and a smooth finish (still very dull), the next step is to oil the metal. I again use Bisley Gun Oil, and I paint this on similar to the blue. I over do the oil, as it cant hurt, and leave it for a about 30 seconds to soak in, although I probably dont need to. Then wipe off the excees oil, and oil up as normal. You should now have a really nice finish. If not, clean of the oil again, and then blue a few more times, then re-oil and see if you are happy. Been about ten years or so scince I needed to blue anything, so if I have missed anything off I do appologise, but I am sure that I will soon be coorected if I have.
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Post by MT01

Hi Shazhib,

Spencerman has pretty much nailed it.

Just a few more comments, apologies if I repeat anything:

1) You seem to have the cleaning and degreasing in hand. You also might want to rub down with very fine steel wool as well before rinsing, drying and blueing. Take care not to touch the cleaned metal with any part of you skin as it will leave grease behind.
I'm also not convinced you need to heat up the super blue solution though.

2) It is really important not to leave the liquid on too long, Birchwood recommend 30 to 60 seconds Maximum, after which you will need to neutralise the process by rinsing off with cold water.
If left on too long the finish will not take - I think it may be that the oxidation layer will begin to be attacked by the blueing liquid after the above period.
The Drum mag is pretty big, and you will find it hard to complete in one 30 second application. I would recommend blueing it in smaller sections at a time with a brush for application. You do not have to rush to do all of it at once so long as you complete all of the mag before letting it cure overnight.

3) As you rinse off the solution with water, you should polish lightly with a very fine steel wool - this will blend in the bits you have done seperately, and if you need to you can then go through the process again to apply another round of blueing (maybe 2 or 3 times depending on how dark and what kind of finish you have)

4) Once you are happy with the result, as Spencerman says - dry thoroughly and oil the metal afterwards to displace any moisture and prevent further unwanted corrosion.

5) You should then let the mag cure overnight, before doing anything else with it.

If you find the blueing comes off too easily, it is most probably because the blue has been left on too long or the metal has not been cleaned and degreased enough.

I've blued a few things in the past using perma blue (not gun parts), and the above process seems to work for me. Good luck

Post by shazhib

Spencerman, MT,

Appreciate your advise. Will try.
Kind regards,

Post by Spencerman

No worries, and just remember, if at first you dont succeed, buy more guns and try again!
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