Clean & lubricate NOS old stock mainsprings or just install?

[mbwatch]

I really feel like I should be able to find an existing thread, but it's not happening today.

I'm about to fit an original Hamilton old stock mainspring into a railroad watch, and it would be so tidy to just slide it right in from the washer. But this spring has to be 50-60 years old and I am hesitant to stick it in with whatever factory lubrication is on there. Do I need to unwind it from the washer to clean and relubricate it before it goes into the barrel? (incurring risk of damage to a hard to find spring).  My heart says no, but my gut and brain say yes.

If my gut is right, what are your opinions on how old a NOS mainspring you are willing to install right from the package?

[Neverenoughwatches]

I guess you have to consider not only how old the spring is but how old the oil on it is.  Ok the oil has never done any work as far as sliding lubrication goes but it has protected the spring from corrosion. The oil has been subjected to the atmosphere in whatever environment that was, humid ? dry ? vacuum sealed packaging ?  If the oil was mineral or worse still organic it has still undergone an aging process.  Even new sealed oil supply has an expiry date if we choose to take notice of it. I can't answer your question for you, but those factors I would be considering Michael. 

[mbwatch]

I think I'm going to unwind it to clean and get a proper coat of 8200 tonight. I just can't imagine whatever factory oil was used in 1960, without vacuum seal, is going to be right for a fine watch I've put so much toward getting everything perfect.

[Neverenoughwatches]

5 minutes ago, mbwatch said:

I think I'm going to unwind it to clean and get a proper coat of 8200 tonight. I just can't imagine whatever factory oil was used in 1960, without vacuum seal, is going to be right for a fine watch I've put so much toward getting everything perfect.

I would have thought Hamilton had used a credible oil of the time. But the fact that it was packed unprotected besides the oil does raise some questions about its life conditions. Is there no possibility of inspecting the oil mainspring under high magnification?  It may give you an idea of its state.

So just a thought, as I recently did this with a Timex that I wasn't fussed about taking apart. How about the idea of cleaning it once its fitted in the barrel. You will need to install it anyway to unwind it.

Once in the barrel you might even get an idea of the oil's condition if you can put in some wind . Is the watch fully assembled except for the barrel ?

[mbwatch]

12 minutes ago, Neverenoughwatches said:

Is there no possibility of inspecting the oil mainspring under high magnification?  It may give you an idea of its state.

I've got loupes but no microscope. What would I be looking for other than grime and dust? It looks very clean coiled in the washer, came from a wax paper envelope.

[Neverenoughwatches]

33 minutes ago, mbwatch said:

I've got loupes but no microscope. What would I be looking for other than grime and dust? It looks very clean coiled in the washer, came from a wax paper envelope.

Ok forget the lathe now and get a microscope . I think what's important would be moisture ingress and I doubt without super high magnification you're not going to see that. Other than that dried lubrication that would be stiff/sticky stopping the mainspring from unwinding cleanly. I think you stand a chance confirming something when its in the barrel and wound up to seperate the coils.

What I did with the Timex was to have some wind in the barrel, everything fully assembled at this time. This seperated some of the coils, then I gave it a spell in the US and gradually applied more wind to seperate different coils. Finally I injected break cleaner into the opening with a hypo needle, was a big opening so that helped a lot. Basically I was being just plain lazy and I wanted to test the Timex recommend cleaning proceedure. It actually did ok.

[mbwatch]

22 minutes ago, Neverenoughwatches said:

I wanted to test the Timex recommend cleaning proceedure. It actually did ok.

It almost always does, unless the pivots are caked in grease.

29 minutes ago, Neverenoughwatches said:

Ok forget the lathe now and get a microscope

Every day now I spin the wheel to determine whether it's microscope, lathe, or jacot next. I've got a little batch of watches for sale and if they go for decent then I might raise enough for one of them.

[Knebo]

48 minutes ago, mbwatch said:

microscope, lathe, or jacot next

Microscope, definitely. 

Even to inspect your work from the Jacot lathe, I feel that a microscope is necessary or at least extremely helpful. 

Edited January 7 by Knebo

[Neverenoughwatches]

3 hours ago, mbwatch said:

It almost always does, unless the pivots are caked in grease.

Every day now I spin the wheel to determine whether it's microscope, lathe, or jacot next. I've got a little batch of watches for sale and if they go for decent then I might raise enough for one of them.

Personally I think Microscope, I know Michael that you are younger than a lot of us here so your eyesight is probably better than most of us. I didn't really get into the loupe idea, initially I managed sort of....i didn't know a Microscope was even a watch tool at the time, I wasn't in any forums and had only watched Mark's videos and he doesn't use one. I just thought what can i use to make this easier as my depth perception was crap, so googled microscopes. Picked one up for a hundred from a guy that used it to repair electronics, phones and the like. As they say ...it was a game changer for me. Then a lathe then a jacot, the Microscope has had 100s more time than either of the other too. Without it I may have even given up by now or at best moved onto clocks.

[mbwatch]

34 minutes ago, Neverenoughwatches said:

I know Michael that you are younger than a lot of us here so your eyesight is probably better than most of us.

Well old enough to have a kid starting in a university; the last 2 years my up close vision went off a cliff. 

[Neverenoughwatches]

25 minutes ago, mbwatch said:

Well old enough to have a kid starting in a university; the last 2 years my up close vision went off a cliff. 

We probably got around 15 years on you then . Lol eyesight does go downhill very quickly. So I expect a microscope is going to make a big difference to you. Its just nice to have a comfortable seating position.

[JohnR725]

On 1/6/2025 at 3:12 PM, mbwatch said:

stock mainspring into a railroad watch

I don't suppose we get a better description like a model number?

Then mainspring lubrication is always a interesting one. Somewhere I can't remember within the last week or so I read a reference to Teflon was used so that would be dry and should last forever at least in the package. Then there is other suggestions of various liquid lubrication that we typically never see on the Springs Gazette always looked dry to me. Then I think I've also seen that you're not supposed use solvents to clean your mainspring but maybe that's because are worried about you cleaning off the invisible lubrication.

If you have concerns you can always just pop it out the ring and just wipe the spring off the other thing it's always interesting  when mainsprings are removed from rings are what are their condition in. I noticed lately a lot of new mainsprings that have a slight yellow color rather than shiny white and they tend to be partially set. So I have no idea where these new mainsprings are coming from but they're not doing her heat treating the way they should.

 

 

[mbwatch]

1 hour ago, JohnR725 said:

I don't suppose we get a better description like a model number?

 

If it's relevant! It's a Hamilton 992, mainspring is 718040. I believe this is from Hamilton's mid-20th century parts numbering and is a yellow color steel. If it is an alloy, it is not like a modern alloy. And it's an older serial from before they switched to motor barrels.

I installed it last night after a battle. I did unwind it from the washer to clean and relubricate it with 8200. It was not set at all - one coil inward and then reversing into a huge S curve. Pictured along with the old spring I removed.

And I regret unwinding it from the washer. I found it very difficult to install - as a T end, to get seated into the tiny hole in the barrel edge. The spring's strength meant it took several tries to transfer from my Marshall pocket watch winder, even if the hole was perfectly aligned. When snapping out of the winder, the T end would jump free of the hole in the barrel. And multiple wind attempts inevitably deformed the inner coil so it wouldn't hook onto the arbor. I had to manipulate it to get that back into shape but have lost confidence that it will be good enough long term.

@JohnR725 I know you have a lot of experience on American watches. Have you dealt with a spring like this? I didn't take a photo while it was still in the packaging washer, but the inner coil was never centered and does not reach close to the center of the barrel at all. It was coiled out at the edge with the rest of the spring, so when installed, the barrel arbor has to force the inner coil over to the center. This seems to me like it would cause a lot of wear on the barrel and lid. But this is a Hamilton original spring so I want to trust they knew what they were doing.

After the trouble to install it, I have only seen a modest amplitude gain from like 210° on that old spring up to about 225° horizontal. So I have more work to do because it I'd like to keep the verticals over 200.

Here's what I mean about the inner coil being far off center. When in the arbor is installed, the spring is putting a lot of outward force against the arbor holes in the direction of the arrow.  Maybe this was normal but I have not encountered it before. I think this is the first time I have installed an old stock pocket watch spring.

Edited January 8 by mbwatch

[JohnR725]

On 1/8/2025 at 4:35 AM, mbwatch said:

I regret unwinding it from the washer. I found it very difficult to install - as a T end, to get seated into the tiny hole in the barrel edge. The spring's strength meant it took several tries to transfer from my Marshall pocket watch winder, even if the hole was perfectly aligned. When snapping out of the winder, the T end would jump free of the hole in the barrel. And multiple wind attempts inevitably deformed the inner coil so it wouldn't hook onto the arbor. I had to manipulate it to get that back into shape but have lost confidence that it will be good enough long term.

If you left the mainspring in the washer you definitely would've regretted that. Anything that has a protruding T type mainspring the best way to do it is with a mainspring winder. But as it's a common enough subject I have pictures

This is for an Elgin spring wind it in but leave a little bit out. How much you leave out depends upon the barrel of the spring too much is definitely a problem to try to get it all in see what a leave out as little as possible this is about right.

Next picture is a little hard to see but rotate until whatever sticks out is over the hole. Then you want to push it into the hole verify that it is indeed in the hole in other words Turn it over and look make sure it's there. Now you absolutely cannot press it out at this time because it will jump it will always jump unless either with your strongest biggest screwdriver or the back into your tweezers whichever works best do what I show in the picture. Hold the end in place and push out the spring. Only if you hold it in place is it going to stay otherwise it will never stay word supposed to be.

On 1/8/2025 at 4:35 AM, mbwatch said:

I know you have a lot of experience on American watches. Have you dealt with a spring like this? I didn't take a photo while it was still in the packaging washer, but the inner coil was never centered and does not reach close to the center of the barrel at all. It was coiled out at the edge with the rest of the spring, so when installed, the barrel arbor has to force the inner coil over to the center. This seems to me like it would cause a lot of wear on the barrel and lid. But this is a Hamilton original spring so I want to trust they knew what they were doing.

What makes you think it's an original spring was it in actual original Hamilton package? As there are a lot of companies that made Springs for various watches but they were not original spring's. Then yes that weird not being centered is definitely not good. I know people that are very concerned about it and typically because I only have the one mainspring I use it anyway. I have a probably wishful thinking that once it all gets wound up nice and tight that maybe it will just stay word supposed to be had not put all that side pressure on the barrel. Oh and then because this is a pocket watch I use 9504 grease on the arbor as it is a really high-pressure location

On 1/8/2025 at 4:35 AM, mbwatch said:

After the trouble to install it, I have only seen a modest amplitude gain from like 210° on that old spring up to about 225° horizontal. So I have more work to do because it I'd like to keep the verticals over 200.

As you started the conversation with mainspring is not servicing of a pocket watch. I would be curious about on the timing machine dial up dial down and crown down what do they look like? Dial-up and dial down and looking for dramatic differences in amplitude indicating that the pivots need to be refinished or the staff worst-case has to be replaced.

Then you also have things like escapement adjustment like banking pins that are movable hopefully they're in the right place? Pocket watches have been around long enough the people of played with just about everything that can be moved unfortunately.

Oh what it's not going to make a huge difference but  your left ankle should be 48° for Hamilton 992.

 

[mbwatch]

2 hours ago, JohnR725 said:

Then you want to push it into the hole verify that it is indeed in the hole in other words Turn it over and look make sure it's there. Now you absolutely cannot press it out at this time because it will jump it will always jump unless either with your strongest biggest screwdriver or the back into your tweezers whichever works best do what I show in the picture. Hold the end in place and push out the spring.

Hi @JohnR725 and thanks for your reply! This is the info I needed. I tried installing the spring several times because I was having such difficulty. The best I did was to leave the T end out about 5mm of the winder, enough that I could see it and set it into the hole, but I did not try to hold it in place with a tool. Seems obvious now.

2 hours ago, JohnR725 said:

What makes you think it's an original spring was it in actual original Hamilton package?

Yeah, the spring was in a Hamilton package with a mid-century Hamilton stylized H logo. But not labeled as "Dynavar" or whatever Hamilton's trademark alloy was named.

2 hours ago, JohnR725 said:

I have a probably wishful thinking that once it all gets wound up nice and tight that maybe it will just stay word supposed to be had not put all that side pressure on the barrel. Oh and then because this is a pocket watch I use 9504 grease on the arbor as it is a really high-pressure location

I have been using HP1300 on the barrel arbor, but will take your suggestion and increase to 9501 (which is what I have). Since this is a going barrel and not a motor barrel, the arbor is in motion relative to the barrel but not the plates, do I have that right?

2 hours ago, JohnR725 said:

As you started the conversation with mainspring is not servicing of a pocket watch. I would be curious about on the timing machine dial up dial down and crown down what do they look like? Dial-up and dial down and looking for dramatic differences in amplitude indicating that the pivots need to be refinished or the staff worst-case has to be replaced.

By and large it is all decent and I had been hoping to finish it off by replacing the old tired spring. And yes, I do have the lift angle at 48°, as found on another thread. My readings are accurate.

New spring:

DD 220° / DU 210° / PU/PD 195° / 5s-8s delta in the horizontals. I'm going to re-clean the upper balance jewels and pivot tonight

Old spring:

DD 210° / DU 200° / PU 180°

And it has a little bit of a poise issue PU that was not initially solved with static poising. My last task is to finish dynamic poising. It isn't dramatic, just a -20s loss when PU. If it was any position other than PU I would leave it alone. So given those numbers, you can see why I was hoping a new mainspring would help more than it did. At 24 hours, it has essentially no amplitude loss with the new spring (old one lost 15-20°) so I am satisfied with that but I do need more power overall.

I am going to do a little more cleaning of the balance pivots and the pallet arbor pivots too. The pallet arbor has cap jewels and I put 9010 as I would not have done without cap jewels. Since I'm going to clean them I will see how it performs without 9010 there first. I don't have tooling to refinish pivots, though if I look closely and find that one of the balance pivots is badly worn I do have the ability to replace the staff. When I started on this movement, it had broken balance hole jewels which I replaced. Scoring on the balance pivots would therefore not be surprising.

I am intending to gift this watch to someone in about 6 weeks so I am down to where I can't dork around with too much more experimentation, given how little time I am actually able to spend at the bench any week and the wait time for parts. The recipient is probably never going to wear it out so 1 adjustment would be enough for the desk clock it is likely to become, but the recipient also knows about railroad timekeeping and so will really appreciate the efforts to restore it at least to "sort of RR-ish"

Edited January 11 by mbwatch
lift angle confirm

[JohnR725]

5 hours ago, mbwatch said:

But not labeled as "Dynavar" or whatever Hamilton's trademark alloy was named.

Looking in the older Hamilton parts book of course gives the old numbers. Looking at a 1960 something book of course gives other numbers. Then the Dynavar Was not made for the 992 only for the 992B series. Then your part number does correspond to the part number in the catalog so that is the right part number and is also listed as a steel mainspring.

6 hours ago, mbwatch said:

without 9010 there first

For what it's worth my favorite oil is 9020 so I never use 9010 on anything.

6 hours ago, mbwatch said:

balance hole jewels which I replaced

American parts books can be quite interesting. For instance it depends on whether your watch had a single roller or a double roller as depending upon the serial number they changed in production. The staff numbers actually have three different pivots sizes and know the parts book does not tell you which pivots size you're supposed to have. Typically on 21 jewel it would be the smallest.Then for the jewels they come in three sizes also to correspond with the pivots of staff. I was thinking a might've been a binding issue but if you have the smallest size pivots all the jewels are bigger so it should be fine worst-case if you had the biggest rule but I don't think that be a huge problem?

You didn't mention the beat and I was like to see pictures of the timing machine just because?? Things like amplitude should be a little bit higher but seeing as how the watch keeps time over 24 hours and it's a gift. Somebody will be extremely happy when they get the watch and it's really not gone matter that much Then usually if you are having pivot issues you would usually see a much more dramatic difference between dial up and dial down is usually one of them is really bad not just both of them bad they could both be bad but typically not.

 

[Neverenoughwatches]

13 hours ago, mbwatch said:

and thanks for your reply! This is the info I needed. I tried installing the spring several times because I was having such difficulty. The best I did was to leave the T end out about 5mm of the winder, enough that I could see it and set it into the hole, but I did not try to hold it in place with a tool. Seems obvious now.

Hi Michael,  since John suggested it would have been a bad idea to fit the spring straight from the holder into the barrel....I am curious to know how you removed it from the holder to begin with ?

[mikepilk]

I started on pocket watches, so came across these quite often.  I hate them . 

I'm working on a Longines 30LS, which has a T end on the mainspring.  I use the method shown by @JohnR725 above. But even then, the bit jumped out of the hole. If it is close to the hole, you can usually push the spring round far enough. I use some brass rod, filed flat on the end to push on the T end bit that sticks up. 

From the "Chicago School of Watchmaking", Lesson 5

Edited January 12 by mikepilk

[mbwatch]

1 hour ago, Neverenoughwatches said:

Hi Michael,  since John suggested it would have been a bad idea to fit the spring straight from the holder into the barrel....I am curious to know how you removed it from the holder to begin with ?

Hi Rich - Removed the spring from its washer? Same as I would from a mainspring barrel - lifted the inner coil free with tweezers while pinching the rest between thumb & finger, and gradually walked the spring out without drama.

48 minutes ago, mikepilk said:

If it is close to the hole, you can usually push the spring round far enough. I use some brass rod, filed flat on the end to push on the T end bit that sticks up. 

This is what I ended up doing on a few of my install attempts. I think only once did I get it in the hole directly from the winder, but had to remove it again to reshape the inner coil. Except I used the butt of my brass tweezers.

[Neverenoughwatches]

3 minutes ago, mbwatch said:

Hi Rich - Removed the spring from its washer? Same as I would from a mainspring barrel - lifted the inner coil free with tweezers while pinching the rest between thumb & finger, and gradually walked the spring out without drama.

Ah ok I haven't tried to do that before, I remember some folk saying it was a bad idea with both sides of the spring being open.   You've proved them wrong .

Out of curiosity what did you think to the lubrication once the spring was out ?

[mbwatch]

7 hours ago, JohnR725 said:

I was thinking a might've been a binding issue but if you have the smallest size pivots all the jewels are bigger so it should be fine worst-case if you had the biggest rule but I don't think that be a huge problem?

I don't detect any binding. The balance is so free in fact that it will oscillate a solid 2 minutes with a strong puff of air. The replacement hole jewels I bought from a guy who makes them to spec, and if I recall I actually ordered the wrong ones the first time too small, so maybe the staff is a replacement with larger pivots than the 21j original. In any case, the balance has excellent motion and freedom now.

 

7 hours ago, JohnR725 said:

You didn't mention the beat and I was like to see pictures of the timing machine just because??

Happy to show it off. It took me half a day to get it there but it is dead in beat. Pictured DD and PU at about 2/3 wind (its worst position right now)

[Neverenoughwatches]

On 1/8/2025 at 12:35 PM, mbwatch said:

And I regret unwinding it from the washer. I found it very difficult to install - as a T end, to get seated into the tiny hole in the barrel edge. The spring's strength meant it took several tries to transfer from my Marshall pocket watch winder, even if the hole was perfectly aligned.

I had this same problem with Soviet movements , Raketa in particular are all T- end springs. Once uncoiled in the barrel they are too tight to shift along into the hole. I ended up putting the springwinder into the inner coil and winding it up a little to release some of the tension the carefully tease the T around to where it's supposed to go. Then John posted his little trick which I now follow but still use a spring winder if I happen to miss the hole.

[mbwatch]

12 minutes ago, Neverenoughwatches said:

Ah ok I haven't tried to do that before, I remember some folk saying it was a bad idea with both sides of the spring being open.   You've proved them wrong .

Out of curiosity what did you think to the lubrication once the spring was out ?

I'm not saying it was a good idea, only that I did it successfully. Maybe it's easier on a strong pocket watch spring than on a finer alloy wristwatch spring. The lubrication seemed totally dry, I could not detect any really but I expect there was some kind of coating during manufacture. I scrubbed it with naphtha and ran a film of 8200 on it.

[RichardHarris123]

The barrel could be converted to a  hook but is that sacrilege?

[mbwatch]

1 minute ago, RichardHarris123 said:

The barrel could be converted to a  hook but is that sacrilege?

On some random old Raketa, no. But on a railroad watch like mine, yes.