The impossible task to find a sweeping seconds hand...

[hautehorloge]

Hey! :-)

 

Before I ask you guys for some advice, I’d like to thank everybody that maintains and participates in this beautiful place of knowledge.

 

Today, I’m asking for advise in finding a very specific shape and style of a sweeping center seconds hand that I try to replace. The shape seems rather simple, yet I’ve struggled to find the right length or specific shape of what I’m looking for.

 

Here is a technical drawing:

 

 

I’m looking for a long arrowed center seconds hand in blued steel with 18.5mm total length. The tube should ideally be fitting a 0.25mm pinion although I can also broach or refit it in case I cannot find the right tube size. The length seems to be the main problem. Anybody got an idea / a source / THIS hand in their parts bin to help me out?

 

Thank you very very much in advance!

All the best!

[WatchMaker]

In lieu of someone coming up with the hand you need, or a source to buy from, I've got something that probably fits into your category of an idea! 

You can pick up generic second hands relatively inexpensively from a source like Cousins: https://www.cousinsuk.com/product/centre-seconds-by-size; they do the 0.25mm you need. Now whilst it looks like the longest they do is only 15mm note this is from the centre hole to the end; not the entire length. How long is the entire hand? I'm not sure but if I take their scale diagram and do a very simplistic split-the-15mm-into-four I get 3.75mm per quarter. If I then transpose that quarter to the remaining length I can see the entire length will be over the 18.5mm you need:

But you require a squared off end ... so you could carefully file to the length and profile you need. Bingo!

Ah ... but it's not blue. Well that's now over to your requirements and skills. Painting (e.g. airbrushing) is straightforward or you could look at any of the helpful online resources videos on how to hot blue (stainless) steel. 

Edited October 17, 2019 by WatchMaker

[yankeedog]

Bluing  can be tough..it is a chemical  process involving  nasty chemicals. I would  advise against  it.a blue black finish  can be achieved  pretty  easily with different  phosphate  solutions  that are available. Often  advertised  as rust converter. They  change  iron oxide into iron phosphate. 

[rodabod]

To the OP: what country are you based in?

Do you have the hole-to-tip dimension?

[hautehorloge]

To the OP: what country are you based in?
Do you have the hole-to-tip dimension?

I am in the US. The hole to tip should be 13-14mm :-)

[hautehorloge]

Bluing  can be tough..it is a chemical  process involving  nasty chemicals. I would  advise against  it.a blue black finish  can be achieved  pretty  easily with different  phosphate  solutions  that are available. Often  advertised  as rust converter. They  change  iron oxide into iron phosphate. 

 

When the hand is made of steel, only heat is needed :-)

[rodabod]

5 hours ago, hautehorloge said:

 

I am in the US. The hole to tip should be 13-14mm :-)

 

I will look through my large selection of hands when I get time to do it.

[rodabod]

Regarding blued-steel, you more often hear this from the "clockies", but you can't match a real heat-treated blue by chemical blueing.

[jdm]

41 minutes ago, rodabod said:

You can't match a real heat-treated blue by chemical blueing.

Probably, and you can easily deform a wristwatch second hand by heating it.

[yankeedog]

13 hours ago, hautehorloge said:

 

When the hand is made of steel, only heat is needed :-)

This is very true, in the process of heating, as in when tempering, steel does go through different colors  .I do not recall the exact temperatures however.But I do recall that blue is in the spectrum.However I would think that heating such a small piece of metal of an unspecified alloy to an exact temperature to obtain an exact color could require so much art and science as to border on magic.

[hautehorloge]

This is very true, in the process of heating, as in when tempering, steel does go through different colors  .I do not recall the exact temperatures however.But I do recall that blue is in the spectrum.However I would think that heating such a small piece of metal of an unspecified alloy to an exact temperature to obtain an exact color could require so much art and science as to border on magic.

 

The hand should not be hit by the heat directly but lay in a bed of brass filings. It will change colors starting with a dark yellow to purple to royal blue to grey blue. Royal blue is usually reached with 290°C / 550°F. The Swiss do it. So I can do it :-D The magic really is to remove the heat immediately and cool down once the object has reached the desired color.

 

But I won’t say no to a blued hand, ready to be mounted of course. :-)

[hautehorloge]

I will look through my large selection of hands when I get time to do it.

I highly appreciate your effort! Thank you very much!