Page 2 of 3 FirstFirst 123 LastLast
Results 16 to 30 of 43
  1. #16
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    25,622

    Default

    Quote Originally Posted by Anorak Bob View Post
    Thanks Bob,

    Back when you initially described the process, I had looked online for some laboratory fittings thinking that was the easiest route and then I asked my daughter's boyfriend if he could scrounge some ammonia from his father's industrial cleaning products factory. The Melbourne - Perth thing made it all too hard and that idea fizzed out. Your diagram makes it look very simple. I'm enthused again.
    Great.


    How about this for isopropyl alcohol? - http://shop.coles.com.au/online/nati...ubbing-alcohol
    To prevent skin dehydration on sensitive skin that rubbing alcohol is diluted to 640 ml of IPA per litre, so the question is what is it diluted with? I reckon it will be some sort of other evaporative organic - so overall not good.
    What you need is 100% IPA like this http://www.isocol.com.au/products/isopropyl-alcohol also available in a Diggers brand at bunny

  2. # ADS
    Google Adsense Advertisement
    Join Date
    Always
    Location
    Advertising world
    Posts
    Many





     
  3. #17
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    25,622

    Default

    Quote Originally Posted by Hornetb View Post
    Yes, that is a fair point. Contamination is your enemy. To be honest I have probably only done that more towards the end of the process..
    Yeah the first couple of things I tried were quite patchy. Then I started using gloves and double rinsing and things improved. I should have know better as I worked for many years in an ultra clean laboratory where we went to extremes to minimise contamination.

    When I actually blow with compressed air it is usually when I'm doing a rifle barrel and I do it mainly to clear water from the rifle bore as that is my biggest concern with rust and I dont want that rusting at all. A lot of people plug the ends of the barrel with wooden dowels to keep the water out, but I'm nervous to leave it locked up for the week it takes to blue. You can coat the bore with lacquer and then use lacquer thinner to clean it out at the end too. This of course relates mainly to firearms.
    I can understand that

    I do plan to set up a hot bluing set up, but this is another level of danger with boiling hot sodium hydroxide and potassium nitrate just for added fun. But the process is much quicker and easier, but the consequences a lot nastier.
    Folks on here will know I am up for most things but my small scale, relatively slow, needs don't warrant the risks that come with hot bluing.
    I don't mind the process being slow as I have many other projects on the go and things to do in between the steps of the fuming cycles.

  4. #18
    Join Date
    Jul 2006
    Location
    Adelaide
    Posts
    2,660

    Default

    Bobl and Hornetb
    Why do you your methods over the manganese phosphate ie Parkerising method

  5. #19
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    25,622

    Default

    Quote Originally Posted by eskimo View Post
    Bobl and Hornetb
    Why do you your methods over the manganese phosphate ie Parkerising method
    My understanding of Parkerising is that it is quicker and provides a stronger more robust coating than the oxides, but the process (especially the manganese version) is trickier.
    There are many recipes with many variations and additives and getting it right is not as straight forward as it seems. Nevertheless, as evident in various firearms forums etc, there are many DIYers having a go with it - just how effective these DIT coatings are I have no idea.

    My main worry with Parkerising is that it involves heating and disposing of large containers of phosphoric acid which I don't find appealing, especially the getting rid of bulk phosphoric acid afterwards makes it a bit of an environmental problem. In the bluing processes the only thing that gets heated and disposed of down the sink is distilled water with a wisp of acid fumes in it. The fuming process uses very little hydrochloric and nitric acid (20 mll of each will do many batches of parts) and there is no disposal required unless you want close up shop and never do any ever again. Bluing acids are also easily disposed of by neutralizing with caustic. The nitrate in nitric acid could be a nuisance but the amounts are so low as to not be a problem.

    It's interesting to see that Parkerising processing services are now being set up in third world countries because gaining environmental approval for large scale Parkerising is getting harder to get in first world countries.

    There are better Parkerizing processes than the Manganese Phosphate method now available using hydrofluoric acid (i.e. nasty stuff) and zirconium, The best recipes are patented and the methods are probably outside most DIY user . If I had access to a decent chemistry lab including a way of disposing of the acids afterwards I would give it a go.

    [EDIT] I had a bit of a read of a couple of Patents for the Fluoro Zirconic Acid method and here is a typical list of ingredients
    Chromic Acid Flake
    CrF34H2O
    CrOHSO4 35%
    Phosphoric Acid 75%
    Thickener
    Surfactant
    Fluorozirconic Acid,
    Liquid Caustic Potash
    DIstilled water

  6. #20
    Join Date
    Jul 2010
    Location
    Melbourne
    Posts
    7,775

    Default

    Quote Originally Posted by Hornetb View Post
    hydrochloric acid (battery acid)
    Make up your mind Isn't battery acid sulfuric?

    Would there be a best before or use by date on a bottle of this once mixed?

    Hi Bob,

    Whats the Aluminium foil for in your vapour transfer setup?

    Stuart

  7. #21
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    25,622

    Default

    Quote Originally Posted by Stustoys View Post
    Make up your mind Isn't battery acid sulfuric?
    Correct

    Would there be a best before or use by date on a bottle of this once mixed?
    It should last for quite a while if its kept in an air tight container.

    Hi Bob,
    Hi Stu.

    Whats the Aluminium foil for in your vapour transfer setup?
    It reflects heat away from the receiver - I forgot to add the light globe..

    The arrangement below is better as it concentrates the warmth on the ammonia feed.
    We controlled the ammonia transfer using a light dimmer on the light globe.
    No heat required a week or so to get a reasonable amount of ammonia into the water - with heat the time it took depended on how much heat was used.
    We used clear teflon PFA 500 ml bottles and back then they cost about $50 each and a teflon connection.
    Because the bottles were teflon we could crank the light globe up and we even used a 150W infra red lamp but this is not possible with PE or it would melt.
    It is possible to purify small amounts of acid like this as well - no water is needed in the receiver
    More metal bluing-2bottlestill-jpg
    Attached Images Attached Images

  8. #22
    Join Date
    Jun 2013
    Location
    Tasmania
    Posts
    92

    Default

    Quote Originally Posted by Stustoys View Post
    Make up your mind Isn't battery acid sulfuric?

    Stuart
    You're right actually . Brain fade moment.

    Not sure where I got the hydrochloric from now, I have about 4L of the stuff.

  9. #23
    Join Date
    Jul 2010
    Location
    Melbourne
    Posts
    7,775

    Default

    Quote Originally Posted by BobL View Post
    Correct
    Am I correct in assuming sulfuric acid isn't an alternate for Hydrochloric acid?


    Quote Originally Posted by BobL View Post
    It reflects heat away from the receiver
    That was my guess at what you were doing. I like plan B much better.

    Thank you

    Stuart

  10. #24
    Join Date
    Jul 2010
    Location
    Melbourne
    Posts
    7,775

    Default

    Quote Originally Posted by Hornetb View Post
    You're right actually ..
    Dont worry I wont make a habit of it

  11. #25
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    25,622

    Default

    Quote Originally Posted by Stustoys View Post
    Am I correct in assuming sulfuric acid isn't an alternate for Hydrochloric acid?

    That was my guess at what you were doing. I like plan B much better.

    Thank you

    Stuart
    My understanding of black oxide methods is that an oxidising acid is needed to make the surface rust.
    This is why nitric or sulphuric are required.
    The HCl is a sort of catalyst to help speed up. the process

  12. #26
    Join Date
    Jun 2007
    Location
    North Of The Boarder
    Age
    65
    Posts
    16,781

    Default


  13. #27
    Join Date
    Oct 2006
    Location
    Armidale NSW
    Age
    50
    Posts
    1,938

    Default

    Thank you for the write up ... I do find this subject very interesting, although I've only ever done Parkerizing (with mixed success).

    One question I have is why does the rust go black when boiled in distilled water? Is it actually changing from "rust" into something else?
    Cheers.

    Vernon.
    __________________________________________________
    Bite off more than you can chew and then chew like crazy.

  14. #28
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    25,622

    Default

    Quote Originally Posted by Vernonv View Post
    Thank you for the write up ... I do find this subject very interesting, although I've only ever done Parkerizing (with mixed success).

    One question I have is why does the rust go black when boiled in distilled water? Is it actually changing from "rust" into something else?
    Rust is a mixture of red ferric oxide (Fe2O3) and water.
    The boiling distilled water converts some the red oxide to the ferrous (black) oxide or FeO.
    The final combination of FeO and Fe2O3 is called black rust or magnetite (Fe3O4)
    Magnetite is moderately more protective against rust than plain iron and especially but it wear off and will still eventually convert to rust.

  15. #29
    Join Date
    Jul 2010
    Location
    Melbourne
    Posts
    7,775

    Default

    Quote Originally Posted by BobL View Post
    and especially
    What Bob, You've got me on the edge of my seat

    Stuart

  16. #30
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    25,622

    Default

    Quote Originally Posted by Stustoys View Post
    What Bob, You've got me on the edge of my seat

    Stuart
    regular orange rust, ie "rust does not protect against rust"

    I can't believe you blokes are paying that much attention - I'd better be careful what I . . . . . .

Page 2 of 3 FirstFirst 123 LastLast

Similar Threads

  1. Blacking As An Alternative to Bluing
    By Anorak Bob in forum METALWORK FORUM
    Replies: 7
    Last Post: 6th Jan 2014, 08:32 AM
  2. Bluing a tapered shaft
    By jack620 in forum METALWORK FORUM
    Replies: 20
    Last Post: 9th Apr 2013, 07:02 PM
  3. My second attempt at steel bluing
    By BobL in forum METALWORK FORUM
    Replies: 19
    Last Post: 22nd Jul 2012, 01:00 PM
  4. Bluing
    By bollie7 in forum METALWORK FORUM
    Replies: 1
    Last Post: 28th Apr 2009, 10:37 PM
  5. Metal bluing solution
    By ohno in forum METALWORK FORUM
    Replies: 28
    Last Post: 16th Dec 2006, 08:00 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •