Bluing hands

[PeterS]

I get you now. Put the hand in the middle of the tray and go with the flame in circles around the sides avoiding the centre, get the heat to work its way from the sides rather than going lengthways heating it up.

[KarlvonKoln]

On 5/3/2021 at 5:14 AM, oldhippy said:

Blotching is a sign of grease which clockboy has said. I always preferred an old English penny to brass shavings. It takes a few practises to get it right. When blued quench the hand in oil it gives a nice shine. That is how I would blue clock screws, getting them all the same colour takes practise.   

Is there a particular kind of oil that works well for this, or any kind that we should *not* use?  Just curious.  I have some old hands I plan to re-blue, and I felt I should learn to do this.

[MechanicMike]

11 hours ago, PeterS said:

I get you now. Put the hand in the middle of the tray and go with the flame in circles around the sides avoiding the centre, get the heat to work its way from the sides rather than going lengthways heating it up.

Bingo! I couldn't have said it better myself! 

Since you're doing some bluing, I had posted a chip tray I made back in January. Works pretty good. Weasol had a good idea to use a clock mainspring barrel and OH had a good idea to use an old penny, which I'm going to try sometime. 

[MechanicMike]

On 6/6/2021 at 9:42 AM, KarlvonKoln said:

Is there a particular kind of oil that works well for this, or any kind that we should *not* use?  Just curious.  I have some old hands I plan to re-blue, and I felt I should learn to do this.

I don't have a clue if there is a correct answer. I can only tell you what I have used and that's any kind of oil that might be at arms length in my machine shop lol it could be lightweight motor oil, way oil, used oil. Just not too heavy. If you find a different answer please let me know! But I've had good luck with them. Real lightweight motor oil seems to work best for me. 2 cycle oil too. 

[MechanicMike]

On 6/6/2021 at 9:42 AM, KarlvonKoln said:

Is there a particular kind of oil that works well for this, or any kind that we should *not* use?  Just curious.  I have some old hands I plan to re-blue, and I felt I should learn to do this.

Forgot to mention mineral oil, food grade and cooking stuff and then theres the expensive commercially made stuff. You'll have to experiment. Also, look up vids on YouTube on "oil bluing." 

Should tell you-I don't use oils all the time. They can become brittle and crack I've found. Sometimes I let them air cool and then just shine/polish them lightly. 

Lots of trial and error on useless hands so I'm not afraid to wreck them!

[oldhippy]

With clock hands I'd quench them in 3-In-One.

[mbwatch]

On 5/3/2021 at 11:24 AM, praezis said:

Quite sure these hands are (nickel-)plated. A bit polishing will not remove the plating. You need pure unplated steel (not stainless steel) or iron for blueing. If cheap or not doesn't matter. 

Huh okay. This might be what I experienced trying to blue screws recently. I had 2 case screws, ratchet & crown wheel screws, and 5 plate screws from a Swiss movement. I cleaned them all in naphtha and 99% IPA then attempted to blue them in brass shavings over my gas cooktop.

The case screws and the ratchet wheel screw blued quickly (though unevenly, I will need to do a better cleaning). But the crown wheel screw I assumed would be identical in composition to the ratchet wheel screw would not change color at all. Ten minutes over a very hot flame and no difference. The same was true for all the movement plate screws, coming out shiny polished silver until I gave up. I'm now wondering if most of those screws were actually nickel plated even though they came from the same movement.

[Hibbz]

I’ve got a question someone here might be able to answer. I’ve just blued some hands for a watch restoration, first time doing it, can I keep and reuse the brass shavings? I don’t see why not, but want to check with someone who’s got some experience. 

[mbwatch]

16 minutes ago, Hibbz said:

can I keep and reuse the brass shavings?

Well I cannot comment on best practice, but I will admit I have used mine many times over. As long as you take a moment to hold them over the flame to burn off any accumulated dust before bluing.

[Hibbz]

Thanks, potted up ready for next use. 

[nickelsilver]

If anything, the more you use the brass filings the better. I have some that are at least 10 years old.