Bluing steel part.

[Nick Hulme]

(Heat) Oxide colouring is great for delicate parts but doesn't offer the increased wear resistance and oil retention of gun blues making it less suitable for larger, regularly used and handled parts.

 

[Buchanan]

Nick

Can one obtain an electric blue or fairly light blue with Gun blue?
Most Gun Blue that I have used over the years gives more of a black blue.
also the blue that I am looking for must be very even, not mottled at all.
any comments would be appreciated.
Buchanan

 

[petertha]

I cant speak for lighter shading aspect but the Clickspring series shows his method & some nice results in terms of evenness & lustre.
http://www.clickspringprojects.com/

 

[Nick Hulme]

Nick

Can one obtain an electric blue or fairly light blue with Gun blue?
Most Gun Blue that I have used over the years gives more of a black blue.
also the blue that I am looking for must be very even, not mottled at all.
any comments would be appreciated.
Buchanan

My point is simply that (Heat) Oxide colouring is great for delicate parts like clock screws which are not often handled but it doesn't offer the increased wear resistance and oil retention of gun blues making it less suitable for larger, regularly used and handled parts, if you used it on a trigger for instance it would begin to wear off with relatively little use.

Unless you recommend (Heat) Oxide blues for firearms and items subject to wear?
Any comments would be appreciated ;-)

- Nick

 

[Buchanan]

Nick.

I am asking from the clock makers point of view. If gun blue gives oil retention and harder wear and I can obtain the color I am looking for, then I want to use it on clocks. Clock oxide blue would not work on guns as you say. Thjanks.

Buchanan

 

[Toolguy]

Nitre Blue for guns gives a similar iridescent bright blue as the heating. It is only for show pieces normally, as it doesn't hold up to a lot of handling as well as a normal hot blue.

 

[Buchanan]

Thank you I will give it a try. how do you stop it rusting?

 

[Toolguy]

I like to rinse well with hot water, oil and let sit for a day, then wipe off oil and wax with car or furniture wax.

 

[Buchanan]

What oil do you use. I can get a good blue but when I oil it, the blue goes dull. I use engine oil.Thanks for the feedback.

 

[Toolguy]

I usually use a vegetable based cooking oil for that. Olive, sunflower, canola, etc. The motor oil may have chemicals that attack the blue. Or skip the oil & go to wax.

 

[Wizard69]

What oil do you use. I can get a good blue but when I oil it, the blue goes dull. I use engine oil.Thanks for the feedback.

I did do some steel blackening and used a gun treatment to provide additional protection. Probably BreakFree or something similar. Got the materials form a sporting goods store if I remember correctly. This certainly isn't blueing in the Blue sense.

These people sell a kit: http://www.caswellplating.com/metal-antiquing/black-oxide-kits.html that seems to meet the needs of model engineers and the like. I suspect it is similar to what I used on a spacer block made for a tool post. It has held up well so far. Interestingly Caswell calls the coating a sealant. I have some other stuff I need to treat so Caswell may be getting an order from me soon. In any event don't have much experience beyond a couple of pieces and there I can't remember where I got the materials. I believe they where Birchwood-Casey.

Side note to myself, I really need to start writing this stuff down, old age is not kind to memory.

 

[scroc]

I have been using a chemical blueing agent from :Brownells:http://www.brownells.com/
They have provided blueing solutions to metal workers for many years.
Rather than deal with heated solutions I use their cold blues labeled "Oxpho-Blue" and "Dicropan T-4", they are both very wear resistant and attractive as well as being simple to use.
Results through out the years have always been great and well accepted by fussy folks.
scroc

 

[Nick Hulme]

Hot blueing chemically changes the surface layer of the steel to the same composition as haematite, it's harder than the steel and is porous allowing it to absorb and hold oil.
Cold processes do not produce a coating of the same composition or wear resistance.

 

[Wizard69]

Hot blueing chemically changes the surface layer of the steel to the same composition as haematite, it's harder than the steel and is porous allowing it to absorb and hold oil.

Cold processes do not produce a coating of the same composition or wear resistance.

Which brings up some interesting questions:

1. Does anybody know of a good web site that covers hot bluing processes from the hobbyist level?

2. Same question for color case hardening especially as an alternative to bluing.

3. Has any one tried the Cerakote type ceramic finishes for use on shop tools? I see potential here as an alternative to bluing but have no experience with respect to durability when handled in this environment.

I ask because i have some tooling bits and pieces id like to blue and was going to go with a kit from Caswell. In the back of my mind though there is this concern that the cold processes aren't as durable as the processes they replace.

In a nut shell looking for a durable but not too complicated way to finish steel parts. Especially parts that will be handled a lot.

 

[enfieldbullet]

Are you trying to blue tooling? if so cold bluing is a good option.

Sure, it isn`t very durable but its good enough for tooling and seems to be what manufacturers use in most parts. Plus, if you keep your tools oiled they shouldn`t rust. Parts that are handled a lot will always develop some patina from handling, but the patina is a good thing as it will keep the part from rusting badly(kind of like rust bluing)

Rust bluing is an alternative...but it takes a LOT of work, which in my opinion is uncalled for in tooling.

hot bluing consists basically of using molten lye (sodium hydroxide) to dip the part in. that bath runs at around 300 degrees celsius.(which could ruin the hardening of parts)

 

[nel2lar]

I might be wrong but the blue that Chris (Clickspring) get on his parts is just surface and very easily removed. Just too much handling will start to thinnen the blue surface. One of his vidoes show it well, the video of the click spring. If you watch the click, you will see the surface that rubs on the gear looses its blue quickly.

 

[Pigi_102]

I must say that it's passed almost 8 months since I blued my part, and she is a boring head.
I don't use her too much, but in this 8 months I've used it quite a bit.

The only places where I'm having some problems are in areas where she was not completely clean before the hot bath in brass, and started to develop some rust.
All the other blued part are still there holding their wonderful blue, and so far I don't see any important scratch.

A boring head is somewhat prone to get scratches for all the chips that reach her during the job. So I'm satisfied.

Pigi

 

[Stieglitz]

Hi Pigi,
Very helpful ,it will be useful on future projects.Thanks for sharing.
Allen.

 

[10thumbs]

Having a degree in gunsmithing, I have used a lot of products for blueing, but the one I keep coming back to for ease of use and durability is Mark Lee Express Blue, available at Brownells.
It is applied with a heat source until chocolate brown and activated by a five minute boiling water bath. Then carded with steel wool or a carding wheel, then waxed while hot. That's it.
It can be a lot of work on gun parts since there is usually so many, but for an odd part here and there, its hard to beat, and I've pretty well quit using hot caustic salts. It comes out a satin black, has good handling resistance, and won't hurt heat treating.
So if you aren't looking for an actual blue color, or a glossy shine, its good stuff.