Omega ultra thin cal 620

[uzii]

First of all I apologize I don't have pictures for this service since it was done before I joined to this lovely forum, anyhow I hope this is the right location to post my notes from this adventure. 

Well, I own this Omega ultra thin very nice watch Cal 620 for ~5Y and recently I decided to service it. Since it’s my 1^st service, it took me some time to get the required oils and extend my tool set. Besides this, as a preparation, I watched one of the excellent series by Mark and learned a lot.

In general, everything went smooth and the main challenge was to deal with very small size of the movement. Another challenge was to clean the movement. I tried to contact some watchmakers to use their cleaning machine but they all refused (they afraid losing market share!!!).  Therefore I followed Mark’s instruction using lighter liquid and clean it manually. I have no doubt that this can never be as clean as cleaning machine but this what I could do L.

At the end, I’ve started to calibrate the watch but I found it very difficult since there is no second hand. After spending few frustrating days trying to calibrate the movement, I understood this impossible without timing machine so I bought a one.

When putting on the timing machine, I discovered that the rate is very unstable and each tiny movement of the regulating lever, the rate changed by ~100 of seconds/day. Examining the balance wheel closely, I found that the end spring is bent and looks like it is touching the neighbor wire while oscillating. It took me few hours back and forth to reshape the spring but finally, the rate became controllable and I got the watch to ~10sec/day!

[clockboy]

Considering the tools you used you have done a real good job. As you have discovered if you continue with this hobby tools are very much a part of horology. Hairsprings & shock springs can be the trickiest parts to deal with so well done sir.  A ultrasonic cleaner for your next project could be an advantage.

[Geo]

Uzii, for a first repair (not attempt) you have done an excellent job.  Not only did you start on a small calibre which is fiddly for most experienced folk, you also had to resolve a timing issue that involved hairspring manipulation.

I'm looking forward to your next project already, and remember to photograph all the steps as it helps educate others. 

[uzii]

Dear friends,

thank you all for the positive feedback this really contributes me a lot. 

High quality tools are always in my mind since I was working as a car mechanic many years ago. I wouldn't start any kind of activity without understanding all steps involved and which tools are needed. Cleaning machine is quite expensive in my country so either I'll by it during one of my travels to US/UK or I'll put extra money here. It feels for me like half work once cleaning is done without the proper equipment. Unfortunately this case will be like buying a cow for cup of milk

thx a lot again, uzi. 

[frenchie]

Great job uzii, and very nice watch!

[bobm12]

Hi uzii! Very good beginning! I'd say, outstanding! The watch is also a beauty...I simply love Omegas. Yes, good tools are not only necessary but essential for quality work...although with the tools you have I have nothing to say about quality, you have lots of that.

As far as a cleaning machine, you can make do with a jewelry ultrasonic one, the cheap ones. Of course, a proper machine would be better. I like the "cow" saying! Although, we all tend to by the cow for that cup of milk (in watchmaking). I don't mind, I have plenty of cows for just one cup of milk...in addition, they keep me company!  This talk about cows...it is strictly horologycal...not to be confused with the wife...

Cheers,

Bob

[dadistic]

Outstanding!

So far, the best I've managed to do is to  adjust several hairsprings into a state of considerable disarray, so you are to be congratulated on your achievement!

[arkobugg]

Hi uzii! Very good beginning!  Very nice work, as a automobil mecanic , I say that you are very thorough and systematic. And that will bring you a long way,,,,   Yes, good tools are necessary and essential for quality work...

As far as a cleaning machine, you can make it you self like I did, see link ..

I have also updated the machin with a dimmer switch, to get it more stabil at low speed.

I use three bottles with fluid.

1 wash is with white spirit   15 min.

2 wash is with red spirit       15 min

3 wash si with isopropyl       15 min

 

 

[clockboy]

I don,t know what red white spirit is but I thought white spirit always left a residue. Perhaps I am wrong.

[bobm12]

Hi Arkobugg,

Isn't Isopropyl an alcohol? With such an extended time anything containing/glued with shellac might come apart I think...have you ever had any problems with it?

When you mention spirit, is that petrol or similar?

Thanks in advance,

Cheers,

Bob

[Geo]

On 22 September 2016 at 8:00 PM, clockboy said:

I don,t know what red white spirit is but I thought white spirit always left a residue. Perhaps I am wrong.

CB, I did a test a couple of years ago between lighter fluid and white spirit to see what residue was left after evaporation.  

This was done by placing an equal drop of each onto a perfectly clean piece of glass then examining the result by viewing the glass in front if a matt black background.  There was only one decernable faint ring and to my great surprise it was made by the lighter fuel, not the white spirit.

[clockboy]

Thanks Geo. I still don,t think I will be using white sprit to clean any of my watch/clock parts. Not convinced it is the best solution to remove old grease/oil etc.

[Geo]

I don't use it for watches myself CB, I only did the test out of curiosity.

[clockboy]

OK

[arkobugg]

On 23.9.2016 at 7:13 AM, bobm12 said:

Hi Arkobugg,

Isn't Isopropyl an alcohol? With such an extended time anything containing/glued with shellac might come apart I think...have you ever had any problems with it?

When you mention spirit, is that petrol or similar?

Thanks in advance,

Cheers,

Bob

Yes the Isopropyl is alcohol, the idea is to use white spirit to clean out old oil, the industry have use this for decades, then I use red spirit ( ethanol) to loose up some more old oil. And the Isopropyl as the final stage, this containes non fat or water.

All three types is low cost, and works fine...

I will also emphasize that is how I do it, I will not say that is tha most optimal way todo it. Under any circumstance.

Maybe we can have an expert to give us some advice??

 

[jdm]

12 hours ago, arkobugg said:

Yes the Isopropyl is alcohol, the idea is to use white spirit to clean out old oil, the industry have use this for decades, then I use red spirit ( ethanol) to loose up some more old oil. And the Isopropyl as the final stage, this containes non fat or water.

All three types is low cost, and works fine...

I will also emphasize that is how I do it, I will not say that is tha most optimal way todo it. Under any circumstance.

Maybe we can have an expert to give us some advice??

I'm not an expert but I do pretty much the same as you do, I use IPA only. However as mentioned I do not leave it long where there is shellac. 

I think the "recommendation" for the solution manufacturers is to use first an ammonia based solution. For me it's not necessary, the pieces I work on are generally clean enough already.

Edited September 27, 2016 by jdm

[arkobugg]

9 hours ago, jdm said:

I'm not an expert but I do pretty much the same as you do, I use IPA only. However as mentioned I do not leave it long where there is shellac. 

I think the "recommendation" for the solution manufacturers is to use first an ammonia based solution. For me it's not necessary, the pieces I work on are generally clean enough already.

For how long do you wash them then?

[mikepilk]

I use a cheap ultrasonic jewellery cleaner. I put the parts in small plastic pots covered with  lighter fluid and sit them in the cleaner which has warm water in. I drop the cleaned parts in isopropyl to clean any residue off. Cheap and efficient for small scale cleaning 

[jdm]

1 hour ago, arkobugg said:

For how long do you wash them then?

10 - 15 mins in the u/s. Sometime if there is some thick oil left on the plates, I wash  them first with water and soap and a toothbrush, then rinse well, rinse with desalinized water, and finally IPA. I may try a little ammonia the next time, I think that that's what gives the shiny appearance for he satisfaction the craftsman,

Edited September 28, 2016 by jdm

[arkobugg]

3 hours ago, mikepilk said:

I use a cheap ultrasonic jewellery cleaner. I put the parts in small plastic pots covered with  lighter fluid and sit them in the cleaner which has warm water in. I drop the cleaned parts in isopropyl to clean any residue off. Cheap and efficient for small scale cleaning 

For how long are the parts in ultrasonic cleaner?

And what is the different between lighter fluid and isopropyl? Couldent it be used insted of lighter fluid?

[arkobugg]

13 hours ago, jdm said:

I'm not an expert but I do pretty much the same as you do, I use IPA only. However as mentioned I do not leave it long where there is shellac. 

I think the "recommendation" for the solution manufacturers is to use first an ammonia based solution. For me it's not necessary, the pieces I work on are generally clean enough already.

What is IPA?

[jdm]

1 hour ago, arkobugg said:

What is IPA?

Isopropyl Alcohol.

[dadistic]

On 9/28/2016 at 7:11 AM, arkobugg said:

What is IPA?

India Pale Ale. A fine adult beverage 

[arkobugg]

15 hours ago, dadistic said:

India Pale Ale. A fine adult beverage 

IPA for the both, while the washing machin does the job...

[mikepilk]

On 28/09/2016 at 1:08 PM, arkobugg said:

For how long are the parts in ultrasonic cleaner?

And what is the different between lighter fluid and isopropyl? Couldent it be used insted of lighter fluid?

The ultrasonic lasts just 3 mins which is usually enough. Lighter fluid is naphtha, a petroleum distillate. It leaves behind an oily residue which is why I rinse with isopropyl. Note that lighter fluid does not dissolve shellac so it's safe to use on balance jewels and pallet jewels. Isopropyl does dissolve shellac so I only rinse balances and pallets briefly.