Replating old Tudor watch case. What is it made of?

[mikepilk]

I'm in the process of replating an old Tudor watch case. 

I assumed it was nickel over brass, but I stripped the nickel and it isn't brass. The surface is quite rough so I want to put on a thick coat of copper first.

I'm using acid copper plating solution. So if the case is zinc, I need to put a thin layer of nickel on first.

Any ideas what metals were used for old watch cases ?

 

[RichardHarris123]

I've no idea about the material but you need a perfect surface before plating, a thick layer won't hide the defects. 

Why do you think it's not brass, it looks brass coloured.  Definitely not zinc. 

[mikepilk]

24 minutes ago, RichardHarris123 said:

I've no idea about the material but you need a perfect surface before plating, a thick layer won't hide the defects. 

Why do you think it's not brass, it looks brass coloured.  Definitely not zinc. 

Nickel plating doesn't cover any defects. But the point of using a copper base, is that you can put down a thick layer which does hide small imperfections. You then polish it flat before the nickel layer. 

I thought it was brass by the colour on the lugs, but this turns out to just be a discolouration. With the nickel removed and polished, you can see the colour below. It could be zinc. I guess the safest thing would be a flash coat of nickel, as that will plate on to most metals, then a thick copper, then nickel.

[RichardHarris123]

Interesting, I've read up on zinc alloy cases, seems to be used on cheap watches.  Tudor, cheap?  I don't think so.  Also once the platting has worn away, corrosion happens quite quickly and the alloy is soft leading to scratches. 

I  think you are correct, a thick plate, rub down, to remove the blemishes and then a final plate. 

[Marc]

I've seen quite a lot of watches of this era which are made from solid nickel with a chrome plating.

In some instances where the chrome has been damaged the underlying Nickel has shown through with a very yellow colour.

[mikepilk]

1 hour ago, Marc said:

I've seen quite a lot of watches of this era which are made from solid nickel with a chrome plating.

In some instances where the chrome has been damaged the underlying Nickel has shown through with a very yellow colour.

I think you might be right. It does look like nickel. 

If it is, it's good news as I can copper plate on to it. I was just worried about it being zinc.

[HectorLooi]

To test if the case is zinc, soak it in vinegar. It should start bubbling like crazy. Nickel is magnetic and should stick to a magnet.

Cases could also be made of brass and then nickel or chrome plated.

[nevenbekriev]

It is nor pure nickel, if it was, then why would You put a new nickel layer on it? It is 'nickel silver', or 'neuezilber', or 'coin silver' with chrome plating. 

[mikepilk]

7 hours ago, HectorLooi said:

To test if the case is zinc, soak it in vinegar. It should start bubbling like crazy. Nickel is magnetic and should stick to a magnet.

Cases could also be made of brass and then nickel or chrome plated.

No reaction to vinegar, and it's not magnetic

[signcarver]

@mikepilk Do you have any idea of the watch's age? 

[mikepilk]

10 hours ago, signcarver said:

@mikepilk Do you have any idea of the watch's age? 

The ETA 2325 is circa 1950s. 

I tried copper plating today and it worked really well - I got a nice thick layer. There were some deep scratches on the lugs - I should have filed more before plating, as I've sanded through the plating getting them out, so I'll have to add a bit more copper plate. But on the rest of the case, the copper has filled the holes and marks really well. 

I'm impressed how much copper plating fills defects. For anyone who's just done nickel plating, I recommend copper plating first. It's like a filler primer spray on a car.

[signcarver]

1 hour ago, mikepilk said:

I'm impressed how much copper plating fills defects. For anyone who's just done nickel plating, I recommend copper plating first. It's like a filler primer spray on a car.

@mikepilk Good to know. I haven't graduated to plating yet, but someday...

fwiw, my ChatGPT app told me that in the 1940s and 1950s, Tudor primarily used stainless steel for their watch cases..

Edited January 23, 2024 by signcarver
added info

[HectorLooi]

Next step, nickel plating. Copper and nickel plating are quite safe but gold and chrome plating involves some toxic chemicals, which I don't think is advisable if you are doing it from home.

[mikepilk]

7 hours ago, HectorLooi said:

Next step, nickel plating. Copper and nickel plating are quite safe but gold and chrome plating involves some toxic chemicals, which I don't think is advisable if you are doing it from home.

I'm quite happy doing nickel plating at home (the only difference to copper plating is that I heat it to about 60°C). I've plated a few cases, but have only just started with the copper. 

I considered gold plating, but then I saw the price of the solutions, and the fact they contain cyanide.

My set up is not expensive. Plastic containers, an old aquarium air pump, a mug heater and a cheap power supply. It works well.

 

Edited January 23, 2024 by mikepilk

[Endeavor]

17 minutes ago, mikepilk said:

I considered gold plating, but then I saw the price of the solutions, and the fact they contain cyanide.

I found that out too. 1 ltr solution contains 1 oz gold and has the price of 1 oz 99.99 gold

I can see that you are quite far in the process, so my old March 2016 thread (coincident with when you joined WRT?) may not be much use to you, but perhaps others could still pick up a few learning's?

https://www.watchrepairtalk.com/topic/3831-design-watch-plating-project/

 

Edited January 23, 2024 by Endeavor

[mikepilk]

23 minutes ago, Endeavor said:

I found that out too. 1 ltr solution contains 1 oz gold and has the price of 1 oz 99.99 gold

I can see that you are quite far in the process, so my old March 2016 thread (coincident with when you joined WRT?) may not be much use to you, but perhaps others could still pick up a few learning's?

https://www.watchrepairtalk.com/topic/3831-design-watch-plating-project/

 

I was following your thread.

I buy ready prepared solutions (or kits of the powders to mix) and anodes from plating supply companies. I do so little they should last me a long time. 

My latest improvements are to use 2 anodes (I was using 1), and anode bags (easily made with cheap polypropylene cloth and a glue gun). I've added the air pump for agitation (I was stirring) and I'm also heating the nickel solution to about 60°C.  I was using 40°C as recommended in a kit, but reading up, the ideal temperature is about 55-60°C.

I created a spreadsheet to calculate the surface area of the watch case, hence current required, and time to give a certain thickness of plating.

It's great fun, and doesn't create any nasty smells !

[mikepilk]

Got there in the end, with some lessons learnt :

1. Copper plating is a great base layer to fill defects. It requires a lower temperature than nickel, and is easy to do (but you must use the proper PDO copper anodes).

2. Don't be too vigorous with polishing the nickel !  I put on about 20 microns, but still managed to go through on an edge when trying to polish out a defect. I ended up re-plating the nickel which I wasn't sure would stick, but if you activate it with acid correctly, there's no problem.

I'm happy with the results. To the naked eye it looks good, with defects only really visible under magnification. I'm still getting a few micro holes, I'm not sure why.

Before

 

 

 

After (it's really hard to take pics of curved shiny surfaces)

Now to fix a VERY embarrassing and expensive error I made when servicing my Breitling Aerospace  

Edited January 24, 2024 by mikepilk

[thor447]

I just ordered a few parts to get started with plating.  This thread was helpful! 

On 1/23/2024 at 3:58 AM, mikepilk said:

 

I created a spreadsheet to calculate the surface area of the watch case, hence current required, and time to give a certain thickness of plating.

 

I would be very interested to hear how you are calculating the surface area of the watch case, and how to figure out what current to apply to copper and nickel plating.  This is something that I'm having difficulty finding.  I even bought a book on the subject, but it just gives wide ranges of voltages, and doesn't really explain how to calculate a good starting current depending on the item being plated.

Edited January 24, 2024 by thor447

[mikepilk]

27 minutes ago, thor447 said:

I would be very interested to hear how you are calculating the surface area of the watch case, 

I just work out the area of a cylinder for the centre, and add on a bit for the lug. I can't attach the spreadsheet, but the calculations are,

Front+back area = (outer radius-inner radius)* Pi²

Sides (inner & outer) = 2 * Pi * depth * (inner radius + outer radius)

Lugs = No. of Lugs * ( length * width *2 + length * depth * 2)    (width and length I use average values)

Add them up to give an area in cm². divide by 100 to get it in dm², as plating currents are often in these units. 

I use Watts Nickel plating solution. Current density are often given as 2-10 A/dm². Lower values give better finish. I use 3 A/dm². So just multiply your surface area by 3 to get the current. You can see below the values I use for nickel removal (4.3), and copper plating (2).  You set the current, and the voltage takes care of itself. 

There's a nickel plating calculator : https://www.goldn.co.uk/nickel-tank-plating-calculator/

and copper : https://www.goldn.co.uk/copper-electroforming-calculator/

 

[Neverenoughwatches]

On 1/23/2024 at 9:24 AM, Endeavor said:

I found that out too. 1 ltr solution contains 1 oz gold and has the price of 1 oz 99.99 gold

I can see that you are quite far in the process, so my old March 2016 thread (coincident with when you joined WRT?) may not be much use to you, but perhaps others could still pick up a few learning's?

https://www.watchrepairtalk.com/topic/3831-design-watch-plating-project/

 

Have read through all that thread, really well put together. Will be coming back to this when i start doing more plating.

[RichardHarris123]

Nice spreadsheet but it's (r (outside) - r (inside))^2 x Pi. Sorry can't do sub/super script on my phone. 

[Neverenoughwatches]

3 hours ago, mikepilk said:

Got there in the end, with some lessons learnt :

1. Copper plating is a great base layer to fill defects. It requires a lower temperature than nickel, and is easy to do (but you must use the proper PDO copper anodes).

2. Don't be too vigorous with polishing the nickel !  I put on about 20 microns, but still managed to go through on an edge when trying to polish out a defect. I ended up re-plating the nickel which I wasn't sure would stick, but if you activate it with acid correctly, there's no problem.

I'm happy with the results. To the naked eye it looks good, with defects only really visible under magnification. I'm still getting a few micro holes, I'm not sure why.

Before

 

 

 

After (it's really hard to take pics of curved shiny surfaces)

Now to fix a VERY embarrassing and expensive error I made when servicing my Breitling Aerospace  

Looks good mike

[thor447]

1 hour ago, mikepilk said:

I just work out the area of a cylinder for the centre, and add on a bit for the lug. I can't attach the spreadsheet, but the calculations are,

Front+back area = (outer radius-inner radius)* Pi²

Sides (inner & outer) = 2 * Pi * depth * (inner radius + outer radius)

Lugs = No. of Lugs * ( length * width *2 + length * depth * 2)    (width and length I use average values)

Add them up to give an area in cm². divide by 100 to get it in dm², as plating currents are often in these units. 

I use Watts Nickel plating solution. Current density are often given as 2-10 A/dm². Lower values give better finish. I use 3 A/dm². So just multiply your surface area by 3 to get the current. You can see below the values I use for nickel removal (4.3), and copper plating (2).  You set the current, and the voltage takes care of itself. 

There's a nickel plating calculator : https://www.goldn.co.uk/nickel-tank-plating-calculator/

and copper : https://www.goldn.co.uk/copper-electroforming-calculator/

 

Brilliant work, thank you.  Would there be any chance of sharing your spreadsheet?  I love the idea and it would save me some time over making one of my own from scratch.  I can send you an email address.  Thank you.

[mikepilk]

1 hour ago, RichardHarris123 said:

Nice spreadsheet but it's (r (outside) - r (inside))^2 x Pi. Sorry can't do sub/super script on my phone. 

My mistake. It should be (R_outside² - R_inside²)*pi*2

[CYCLOPS]

Rio-Grand is a great source and most of my bottles list the volts I believe....