Blackening steel parts

[Graham MeekParticipant @grahammeek88282]

A product I have used with some success is Curator Antiquing Fluid Black. While it is intended for brass the makers say it will work on steel. I must admit I was sceptical when I first read that, but as you can see from the photograph the finish is respectable.

Being a cold process it will never compete with commercial hot salts blacking, but for the odd occasional usage the product is hard to better for the price.

The fluid can be applied neat or the fluid can be diluted 10:1 and the parts immersed for 2 minutes, this is my preferred method. A coat of Shell Enisis after rinsing and drying with an air line is all that is needed.

De-greasing is the key, and I usually use Isopropanol followed by a hot wash in washing up liquid followed by a hot rinse. Rubber gloves are a must.

The photograph of the dial was taken 2 years ago and there are no signs of the blacking wearing off. The dials on the "Myford S7 Tailstock Micrometer Dial" thread were done using the same process.

Regards

Gray

Edited By Graham Meek on 30/11/2018 17:33:51

[JAParticipant @ja]

I posted this question a few years ago.

I was unsuccessful in finding a company that would hot black mild steel (using caustic soda) so I did some trials. I found that I could successfully black screws and nuts down to 12BA by the blacksmith method.

I did over 200 items smaller than 4BA without a scrapper: Heat each item, held by steel wire, individually to red heat in a flame of a cooker gas ring and drop into clean 32 hydraulic oil. Simple but boring.

Since then I have found a firm in east Bristol that will hot black mild steel.

JA

[Stuart BridgerParticipant @stuartbridger82290]

Reading up on the cold blacking processes described here. They seem very similar to industrial phosphating that most of my apprentice pieces were subjected to in the '80s. Although I suspect the chemicals were stronger then. Everything is rust free despite being stored in damp garage for 30+ years .

[JonParticipant @jon]

Depends how good or bad a job you want. If your sights are low use cold blacking, wont last if handled or used it goes on wafer thin and patchy. On a positive anyone can do it, to make it look good smear an oil residue on which masks the patchyness some what.

Theres dozens of legit UK companies that will hot black all over England, Wales and Scotland. Some will do proper cold blacking not the gel stuff in kits.

Another point is you wouldnt oil black a quality part, that best done by hot browning/blacking/blueing whatever you want to call it.

Dont get confused between the cheap cold blacking kits approx £5 a small bottle to the proper cold blacking that runs at 100 degrees. Ones quality the other just a make do for low esteem.

[thaiguzziParticipant @thaiguzzi]

Odd one out here (as usual).

Had great results on steel with USED diesel oil.

Mineral, not synthetic.

Steel component heated up on the gas cooker, purple to grey, then straight in the room temperature oil. Left overnight or at least a few hours.

[Ron LadenParticipant @ronladen17547]

Thanks again for all the advice guys.

I have ordered 500ml of Patination fluid so I will see how that works out. A question, once the diluted solution has been used can it be kept in a container and used again or is it just a one shot thing.

Ron

[Graham MeekParticipant @grahammeek88282]

Hi Ron,

I use 20 ml of the fluid at each mix, I also use distilled water from the shop dehumidifier, not tap water. Kept in a sealed container, such as a small square plastic sandwich box, I have kept the solution for over 12 months. However my usage is very small, 3-4 items per year, but they are relatively large items. Towards the end of the solutions life the blacking takes longer.

For my requirements this is more economical than some of the other cold systems, plus I can use it on brass.

Regards

Gray,

[Brett HurtParticipant @bretthurt41827]

Look at this https://www.youtube.com/watch?v=xmv58Z3RZ9c&feature=youtu.be that is what I do

[JonParticipant @jon]

Ron its not about whether it works, its about the finish and longetivity you will get from the off the shelf bottled or gel kits.
Dont confuse that with the proper 'cold blacking' that the parts have to be heated up to boiling at least 7 times and rusted each time.

[Ron LadenParticipant @ronladen17547]

My first attempt at blacking, seems to have worked ok but whether the finish will last I will have to see.

[VicParticipant @vic]

I’ve used Gun Blue many times and it works very well on small parts giving a very deep black. I find heating the parts a little and them immersing them in the liquid works best. An oil coating afterwards helps protect the surface. Bigger parts are not so easy unless you can afford to buy a gallon of the liquid (it’s not cheap). What I’ve found is that the surface finish hugely effects the blacking process. I’ve personally found shiny or polished parts are much more difficult to black than sand blasted parts. In fact I seldom seem to black parts these days, I just sand blast them then wipe them over with Microcrytalline Wax. Have a look at the pictures of the tool holder in my album. At least one person thought it was a computer generated image.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Vic on 14/12/2018 16:51:42:

… Have a look at the pictures of the tool holder in my album. At least one person thought it was a computer generated image.

.

Hands up … It was me

… and I remain astonished by its loveliness !!

MichaelG.

[VicParticipant @vic]

You weren’t the only one Michael, several others on another forum thought it was a computer generated image.

[Nigel McBurney 1Participant @nigelmcburney1]

I aquired a Frost Auto Restoration blackening kit about twenty years ago,and I still use it occasionally mainly for stationary engine restoration,it still works ok,During apprenticeship days large parts were sent out for "chemical Blacking" probably not so good nowadays due to all the various modern controls and regulation. Small quantities of BA steel instrument screws were oil blacked by putting them with clean lubricating oil in a tin lid over a bunsen burner warming then up until the oil caught alight then let the oil burn off,they were NOT heated to red hot,as this would have ruined the polished finish of the screwheads.

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