Bluing

[RogerH]

Hi all,

as I get further into the field of repair and restoration I come across various techniques used for various parts of the movement and casing. One such technique that I am not too familiar with is Bluing. I understand it but does anyone have any good tips and methods? and would the same method for screws be use for hands? and information, as always, is greatly appreciated.

[Willow]

Hi RogerH,

Look forward to see what anyone has to say on this topic have watched a few videos about it and it seems easy enough, just knowing when to take off the heat to get the right blue, have not tried it yet have to get a blow torch first, suppose it is trial and error and far as the screws and hands are concerned its the same process i think will keep watching.

[KarlvonKoln]

Slapping my forehead.  See, I made a little bluing tray from some sheet "brass" I had (thought it was brass, I did) and drilled it with different sized holes for bluing screws.  Used my spirit lamp, and those things took forever to turn.  Got them to turn blue with a torch though.  And then I remembered something:
A friend, James, had given me some bronze scraps along with some brass.  And time, and an addled memory, had let them get all mixed together.  But, yeah, I made a *bronze* bluing tray.  I think maybe brass may work a tiny bit better for this.  This bronze is a weird kind aluminum-copper-something alloy.  The stuff is acting like a heat sink, robbing the screws of their temperature or something.  Something isn't working well here.  Gonna see if I have real brass in the shed later today. 

[oldhippy]

This is how I blued screws for clocks. I had a hand vice with a bent copper penny that I fixed into my bench vice, spirit lamp under it, I would heat the penny then put the screws on it wait until they turn blue and quench them in oil. You must make sure the screws are free from dirt, oil and grease. The art is to have all the screws the same colour blue. It takes practice. Quenching them in oil ads a shine to the screws. Then wash them, I used an old watch cleaning  machine. 

[RogerH]

1 hour ago, oldhippy said:

This is how I blued screws for clocks. I had a hand vice with a bent copper penny that I fixed into my bench vice, spirit lamp under it, I would heat the penny then put the screws on it wait until they turn blue and quench them in oil. You must make sure the screws are free from dirt, oil and grease. The art is to have all the screws the same colour blue. It takes practice. Quenching them in oil ads a shine to the screws. Then wash them, I used an old watch cleaning  machine. 

Thanks OH, is there a specific oil? and does this work for hands too?

[oldhippy]

I just used 3 in 1 make sure its clean. Providing the hands are steel and not some composition of metal it will work. 

[nickelsilver]

OH's penny technique is great. Similarly I use an old pocket watch barrel will holes drilled in the lid to accept the screws, with a wire handle attached, heating over an alcohol flame. For hands it's a brass try with very fine brass filings. Heating as slowly as possible I find it's not necessary to quench, and a very even color can be had, for watch hands I take a good 5 mins to come up to the blue.

 

Cleanliness is by far the most important thing. And if you miss the blue, all the color must be removed before another attempt.

 

 

Edited August 16, 2021 by nickelsilver

[Orologi67]

Screws are rather easy.

Polish them up.  Hold one in a pair of needle noose pliers over a little glass of oil or water.  (Oil prefered)  heat the screw until you see it turn blue then let it drop into the oil.

Things bigger than a screw will have to be heated slowly in a tray filled with brass or copper shavings.  

[rodabod]

If you use brass shavings, make sure they are relatively clean as well, since if there is oil then it can evaporate and condense onto the work. 
 

Sometimes it can be a bit like scrambling eggs and the part will carry on bluing after you’ve removed the heat. 
 

practice, practice, practice