Micro welding - again (sorry)

[skridlov]

I've asked about this previously but forgive me for starting from scratch again.

In the short term I have a watch which requires building up (less than 1mm probably) a setting rocker bar which doesn't quite push far enough. It's impossible to find a replacement. I also have  a number of cases that require small repairs. Would someone be kind enough to give me a list of the tools and consumables that I can buy on Amazon which would give me a modest cost starter kit to enable me to to at least accomplish the first task (which would, hopefully, cover the price of the tools). My experience of welding is limited to arc welding - primarily hard-facing worn earth moving equipment - and then with advice from a friend on the metallurgical considerations. I've also done some gas cutting. None of which is very relevant to watch repairing. I have however done a lot of small component soldering. I'd expect to practice a little on something disposable before building up the rocker bar.

Advice appreciated.

Roy

[skridlov]

I'd forgotten that I had this bookmarked.

https://www.amazon.co.uk/gp/product/B0136JA0LK/ref=ox_sc_sfl_title_1?ie=UTF8&psc=1&smid=A2KZJ3BPMNX5LT

To which I would have to add?

Roy

[skridlov]

& 

What grade and size of rods would be mot useful for watch components and cases?

[Neileg]

Welding watches? That's a new one on me.

Silver solder is a much more likely technique. A borax flux is often used. The solder comes in easy, medium and hard grades which relates to its melting point. Low MP (easy) is used for fixing cases for example. A hard solder will build up worn levers and other parts.

The oxy propane (or butane) will for small silver soldering jobs. It would also braze using a brass or bronze filler.

 

Still not easy, even with the right gear.

 

Cheers Neil

 

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[Neileg]

 

 

[rogart63]

That ain't going to work.  First of all the silver solder is to soft. That would wear out faster then you can say welding. If it would work you have to laser weld it. There are places that do that. I think that they can do it cheaper then buying that welding machine. Those tubes would not hold that long either. 

[skridlov]

Hmm. Steel cases. Hardly a soldering job I'd have thought. Silver cases (I have a few to repair - typically damaged fixed lugs) would seem to need more heat than an iron would provide - big heat sinks.

Reading the above you'd think that no one makes jewelry! The small "Little Torch" gas welding torches are specifically aimed at jewelry manufacture, which, to me, is little different to fixing watch cases.Welding/brazing/soldering aren't that different. 

One of the  tasks I need to accomplish is to build up a setting lever edge by less than 1 mm so that it moves a rocker bridge far enough. I'm assuming the lever is made of mild steel - and what else but welding/brazing? Tricky but one can always add more than needed and file/polish back.

The above responses are a bit confusing. It doesn't seem like a ridiculous proposition to me. But I could be wrong - I often am in this subject area.

Roy

[ro63rto]

Try contacting prescription glasses repair shops.

I just had my Ray Ban sunglasses repaired by National Frame Repair Services in Lancashire. Very good work but for watches, IF they do help, you'd probably have to refinish it yourself to get all the tolerances down to spec.

Sent from my Honor 5c

[Neileg]

That ain't going to work.  First of all the silver solder is to soft.

Sorry, I don't agree. A hard silver solder is just that- hard.
Other observations
I've seen high pressure hydraulic steel pipes silver soldered as its less brittle than a weld.
A very versatile fixing method now frequently overlooked, as is brazing.
The difference between jewellery and watches is that one has to look right, the other has to be right.

Happy days, Neil


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[skridlov]

I experimentally built up the setting lever on the chrono for which I can't obtain a replacement, using regular tin/lead solder - all that I have available. The watch now sets without jumping teeth. Obviously the solder is soft and will eventually (soon) wear out, although there's enough clearance to build up a little more. And of course solder is readily removed using a solder sucker. Adding a little mild steel weld and dressing with a file would be a permanent fix I'd have thought. It's not a balance staff...

Maybe I need to buy some hard silver solder? 

I still fail to see what in principle is wrong with my original suggestion.

[Tmuir]

At my watch school one member refinishes high end watch cases and deals with large scratches with a TIG (or MIG) micro welder.

This uses stainless steel wire of very small diameter allowing him to deposit the metal to fill in the dings so very little metal is removed from the case.

Unfortunately the machine is worth atleast a couple of thousand of dollars, so unless you plan on doing a lot of this its not a tool most of us can afford.

[Neileg]

I still fail to see what in principle is wrong with my original suggestion.

Heat
Stainless melts at about 1400C, silver solder at around 450C. Gas welding needs to get the whole component hot unlike TIG/MIG which just heats the weld. At 1400C watch components will twist and distort long before you get a chance to weld. At 450C there's still a risk of distortion but dramatically less.
Hope this makes sense, Neil


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[skridlov]

Hmm. again. Obviously I'd like to buy a TIG/MIG welder but equally obviously that's not going to happen.

I'm aware of the need to heat components when brazing/welding but completely ignorant of the metallurgy where watch cases and parts are concerned. 

So back to soldering. I've got numerous cases which show signs of having been repaired, both silver and steel - and more that need some similar work. Obviously somebody used something on them.  The impression I'm receiving is that this sort of repair is impossible short of an investment of ££££s. My little test on the setting lever proved valid, solder limitations accepted so what's the next possible step?

How do I fix silver and steel cases which, typically, need replacement fixed lugs.? And how hard is "hard silver solder" - is it workable with a regular iron or does one need a torch? 

I can't believe that this is an insoluble problem - or maybe I should say an un-meltable one...

Roy

[Tmuir]

Hard Solder is reasonably hard, not as hard as steel, but reasonably hard.

The problem with hard solder is it does not fill gaps, unlike soft solder which can be heated to almost a putty state and worked to fill up a gap you cant do this with hard solder.

When they hard solder a case the solder is used to join to bits of metal, not build up the surface.

What I'm saying is hard solder (silver solder)  (brazing)  is made to join bits of metal, not to build up the surface of an item.

[Neileg]

I can't write you a complete training course on this forum! Do some research on silver soldering, brazing and bronze welding. The techniques are very similar.
You can't use an iron with silver solder, you need a flame. Propane will do but the compact oxy propane torches will be better.
You can't solder stainless steel (not in a home workshop anyway). Brass, bronze, copper, silver will all solder and will deal with broken lugs no problem. You should be able to deal with mild steel too. Getting a decent polished finish on the repaired case is still a challenge.
Cheers Neil


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[skridlov]

Thanks

I certainly wasn't looking for a complete course. But the overall impression has been that it's all quite impossible. Which It obviously isn't. It's not actually that easy to extract the necessary information by searching - you tend to get swamped by irrelevant details. It comes back to needing a torch as well as an iron which is approximately where I started with this enquiry, albeit referring to "welding" rather than brazing (or soldering).

I'm probably going to buy one of the Little Torches. It would be quite useful to be able to gas weld/braze other small items... I think. I'll probably leave off repairing the Grande Complication Patek Phillipe until I've had a crack at a couple of vintage Rolexes.

Roy

[praezis]

On 16.7.2017 at 3:00 PM, skridlov said:

I experimentally built up the setting lever on the chrono for which I can't obtain a replacement, using regular tin/lead solder - all that I have available. The watch now sets without jumping teeth. Obviously the solder is soft and will eventually (soon) wear out, although there's enough clearance to build up a little more. And of course solder is readily removed using a solder sucker. Adding a little mild steel weld and dressing with a file would be a permanent fix I'd have thought. It's not a balance staff...

Maybe I need to buy some hard silver solder? 

I still fail to see what in principle is wrong with my original suggestion.

N.B. If you already applied soft solder, silver (hard-) soldering is no more possible!

Frank

[skridlov]

Not even if the original solder is removed with a solder-sucker?

[Neileg]

Not even if the original solder is removed with a solder-sucker?

Yes and no. A solder sucker will reduce the bulk but you would need to polish out every trace of lead solder.

Good luck Neil


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[skridlov]

Useful information, thanks.

Roy

[measuretwice]

On ‎07‎/‎19‎/‎2017 at 8:14 AM, Neileg said:

You can't solder stainless steel (not in a home workshop anyway).

I've not had a problem silver solder stainless, really no different than other steels or copper alloys imo.  I mostly use easyflo 45 and either propane or oxy acetylene (for larger stuff).   All the usual rules apply about indirect heating and not getting things too hot.

I'm curious where you've had trouble with it?

I agree with you on the heat bit, a micro plasma welder would be just thing but they're not something you see in every shop.  you can weld .002 foils with them if so inclined

[Neileg]

Never tried it myself. I worked for a SS fabricators and the guys said it was "just wrong" as soldering is inherently dirty.
This was in an environment where mirror finish, crevice free joints were the routine.
Maybe your experience is more relevant to watchmaking but it's not a good place to start for a novice.
Cheers Neil


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