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sstakoff

Dial Feet Soldering Video

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A work colleague asked me to have a look at his Ebel 1911 Discovery (ETA 7750). The hour counting hand was floating around in the case. Loupe inspection showed that the post was broken off in the hand - so before starting I ordered a replacement hour counting wheel. When I opened the case I found the dial was not attached - it was sliding around under the hands. Removal showed that both dial feet were broken off. Time to break out my dial foot soldering machine. Here's a video showing the technique. Enjoy!

 

 

 

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No marks left on front if done correctly. I probably ruined 5 practice dials experimenting with different solder, flux and technique. Note also that sometimes I use a staking set to support the dial. I use a flat punch that is just the correct size to hold the dial wire perfectly vertical. This is actually the technique I'd recommend. Key is to use the correct solder and to perfect your timing. If you flow the current too long you WILL burn the dial face!

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Does anyone know if a car battery charger would be any good for this?

I have an old charger that can output 12v or 6v which I believe can cope with quite a high current. I was wondering if it would double as a dial foot soldering machine. Does it need to be A/C rather than D/C?

Also, what is the function of the carbon rod? Could you not just make contact with the wire or would that cause a problem?

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17 hours ago, Marc said:

Does anyone know if a car battery charger would be any good for this?

I have an old charger that can output 12v or 6v which I believe can cope with quite a high current. I was wondering if it would double as a dial foot soldering machine. Does it need to be A/C rather than D/C?

Also, what is the function of the carbon rod? Could you not just make contact with the wire or would that cause a problem?

Yes - I believe a car battery charger can work. Have a look at this: http://www.girr.org/girr/tips/tips1/solderer.pdf

You need the carbon rod which serves as the electrode. Carbon is an excellent electrical resistor. It is this resistance that generates the instantaneous, and localized heat required to solder. Without the carbon, you would likely overheat the entire dial and do irreparable damage :(. Carbon rods are cheap and easy to find online. You can file the end down to a pencil tip.

 

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15 minutes ago, sstakoff said:

Yes - I believe a car battery charger can work. Have a look at this: http://www.girr.org/girr/tips/tips1/solderer.pdf

You need the carbon rod which serves as the electrode. Carbon is an excellent electrical resistor. It is this resistance that generates the instantaneous, and localized heat required to solder. Without the carbon, you would likely overheat the entire dial and do irreparable damage :(. Carbon rods are cheap and easy to find online. You can file the end down to a pencil tip.

@sstakoff thanks for the info and the link, I will be giving this a try.

I actually salvaged a carbon rod from an old zinc carbon battery last night so my next step is to obtain some solder paste and conduct some trials. 

I will report back.

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