Braking grease - a myth?

[Kalanag]

For me, a braking grease is essential for the proper lubrication of the highly loaded contact area between the mainspring bridle (steel) and the barrel wall (brass or aluminum). Both in combination serve as a slipping clutch or „brake“ in an automatic watch.

I always doubted the idea that braking grease can be used to prevent the bridle from premature slipping. After searching this forum and the net for some side-by-side testing of bridle/wall lubricants with no success, I decided to do the following test:

1.) take a brand new barrel with mainspring of an automatic watch and find the power reserve

2.) remove all lubricants inside the barrel and test the dry (unlubed) barrel again

3.) oil the inside with D5 and test again

What would you expect?

Here is the barrel of a brand new (Chinese) skeleton watch I used. The opening allows cleaning and lubricating the inside without removing the mainspring and risking a bent spring or bridle.

I counted the turns of the barrel arbor before slipping. To be able to wind the spring I glued a nut on top of the ratchet wheel. The nut was turned with a socket. A mark on the socket helped counting.

Here are the results of my simple testing after 10 repetitions with each setup.

- barrel factory lubed => 7 turns +/- 10°

- barrel dry w/o lubrication => 7 turns +/- 60°

- barrel oiled with Moebius D5 => 7 turns +/- 10°

My expectation before testing was a slightly lower power reserve of the oiled barrel and a significantly higher reserve of the dry barrel. So the result surprised me a lot!

On the other hand the result supports my assumption that a braking grease should not increase the power reserve.

Knowing that my testing does not comply with scientific standards, I am sure we will get at least some interesting discussions.

Edited July 24, 2024 by tomh207
Requested by original poster for title change

[Marc]

12 minutes ago, Kalanag said:

For me, a breaking grease is essential for the proper lubrication of the highly loaded contact area between the mainspring bridle (steel) and the barrel wall (brass or aluminum). Both in combination serve as a slipping clutch or „brake“ in an automatic watch.

I always doubted the idea that breaking grease can be used to prevent the bridle from premature slipping. After searching this forum and the net for some side-by-side testing of bridle/wall lubricants with no success, I decided to do the following test:

1.) take a brand new barrel with mainspring of an automatic watch and find the power reserve

2.) remove all lubricants inside the barrel and test the dry (unlubed) barrel again

3.) oil the inside with D5 and test again

What would you expect?

Here is the barrel of a brand new (Chinese) skeleton watch I used. The opening allows cleaning and lubricating the inside without removing the mainspring and risking a bent spring or bridle.

I counted the turns of the barrel arbor before slipping. To be able to wind the spring I glued a nut on top of the ratchet wheel. The nut was turned with a socket. A mark on the socket helped counting.

Here are the results of my simple testing after 10 repetitions with each setup.

- barrel factory lubed => 7 turns +/- 10°

- barrel dry w/o lubrication => 7 turns +/- 60°

- barrel oiled with Moebius D5 => 7 turns +/- 10°

My expectation before testing was a slightly lower power reserve of the oiled barrel and a significantly higher reserve of the dry barrel. So the result surprised me a lot!

On the other hand the result supports my assumption that a breaking grease should not increase the power reserve.

Knowing that my testing does not comply with scientific standards, I am sure we will get at least some interesting discussions.

An interesting test indeed. However with at least one dangerous assumption, and one omission.

The assumption being that "fresh from the factory" equates to appropriately lubricated with a braking grease. Had this been of Swiss or Japanese origin then the assumption may not have been as problematic, however my understanding (and I will confess this is from reading not direct experience) is that one of the problems with the Chinese movements is the lack of appropriate, or even any, lubrication.

The omission being to repeat the test with a known braking grease applied, which would have negated the assumption and given a known and verifiable result for braking grease.

10 out of 10 though for experimenting.

[RichardHarris123]

Definitely full marks for experimentation.  Another factor is is wear on the barrel wall without lubrication. Steel constantly rubbing on brass/ aluminium, I  can't see it surviving for long. 

[Kalanag]

24 minutes ago, Marc said:

An interesting test indeed. However with at least one dangerous assumption, and one omission.

I am fully aware of the mentioned assumption and omission. Nevertheless both do not undermine the finding that a dry wall does not „brake better“ than an oiled one. And why should braking grease brake better than a dry wall?

15 minutes ago, RichardHarris123 said:

Steel constantly rubbing on brass/ aluminium, I  can't see it surviving for long. 

That‘s exactly what I think braking grease is for!

Edited July 23, 2024 by Kalanag

[rjenkinsgb]

59 minutes ago, Kalanag said:

And why should braking grease brake better than a dry wall?

Not exactly the same thing, but - have you ever noticed that the volume controls on good quality audio equipment "ooze" round rather than turning freely?

That's purely due to the spindle being lubricated with a purpose made grease, "Kilopoise" or similar:

https://www.farnell.com/datasheets/494932.pdf

 

Purpose made braking greases could have equally strange properties, partly gelled or something like that?

 

[HectorLooi]

2 hours ago, Kalanag said:

For me, a braking grease is essential for the proper lubrication of the highly loaded contact area between the mainspring bridle (steel) and the barrel wall (brass or aluminum). Both in combination serve as a slipping clutch or „brake“ in an automatic watch.

I always doubted the idea that braking grease can be used to prevent the bridle from premature slipping. After searching this forum and the net for some side-by-side testing of bridle/wall lubricants with no success, I decided to do the following test:

1.) take a brand new barrel with mainspring of an automatic watch and find the power reserve

2.) remove all lubricants inside the barrel and test the dry (unlubed) barrel again

3.) oil the inside with D5 and test again

What would you expect?

Here is the barrel of a brand new (Chinese) skeleton watch I used. The opening allows cleaning and lubricating the inside without removing the mainspring and risking a bent spring or bridle.

I counted the turns of the barrel arbor before slipping. To be able to wind the spring I glued a nut on top of the ratchet wheel. The nut was turned with a socket. A mark on the socket helped counting.

Here are the results of my simple testing after 10 repetitions with each setup.

- barrel factory lubed => 7 turns +/- 10°

- barrel dry w/o lubrication => 7 turns +/- 60°

- barrel oiled with Moebius D5 => 7 turns +/- 10°

My expectation before testing was a slightly lower power reserve of the oiled barrel and a significantly higher reserve of the dry barrel. So the result surprised me a lot!

On the other hand the result supports my assumption that a braking grease should not increase the power reserve.

Knowing that my testing does not comply with scientific standards, I am sure we will get at least some interesting discussions.

Did you carry out the same test with braking grease applied to the barrel?

Another factor to consider is the amount of slippage that occurs, i.e. the number of turns left to power down to zero.

I have always wondered if "damping grease", the stuff used for audio potentiometer shafts and camera lenses, would work better as a braking grease. That stuff is so much cheaper than anything with the name Moebius on it.

Maybe I'll test it out, as I have a whole jar of it.

[Kalanag]

31 minutes ago, HectorLooi said:

Did you carry out the same test with braking grease applied to the barrel?…

My assumption was that braking grease was applied by the factory. There‘s no proof though.

[Geotex]

If you aren’t opening the barrel and removing the spring to clean and lubricate (or not lubricate), how do you access and experimentally control the space of interest which is between the outer coils and the walls? Even with skeleton fenestrations you can’t really clean without disassembly, can you? Or maybe I misunderstood your methods.

[Knebo]

This is an extremely interesting test! Thanks for doing this.

 

13 minutes ago, Geotex said:

If you aren’t opening the barrel and removing the spring to clean and lubricate (or not lubricate), how do you access and experimentally control the space of interest which is between the outer coils and the walls?

I was also wondering about this. My initial understanding was the you'd apply D5 as a [wrong] breaking grease (i.e. to the barrel wall) for the 3rd test. But now I'm wondering if you did or not.

Also, how did you clean the barrel's initial (presumptive..) lubrication? I understand that you left the barrel assembled. I see that the barrel lid is skeletonized, but I still wonder if lubrication can effectively be cleaned this way. How did you do that?

[spectre6000]

I. LOVE. THIS. 

I'm trying to keep a baby from melting down though, so I have nothing to contribute at the moment.

[HectorLooi]

Another thing that has been bothering me recently is certain greases seem to separate after awhile. Especially the 9504, there seems to be a dark blue liquid and a lighter paste like substance. Should the grease be given a thorough mix to homogenize everything again?

Even my 9415 seems to be more liquid than when I first got it. Maybe it's the crazy hot weather that we've been having.

[mikepilk]

I use 8213 for braking grease. I notice on my jar that the expiry date was 2020  

Cousins only sell 20ml jars, and l have only used about 1ml !

Is there a synthetic equivalent ?

[Kalanag]

5 hours ago, Geotex said:

If you aren’t opening the barrel and removing the spring to clean and lubricate (or not lubricate), how do you access and experimentally control the space of interest which is between the outer coils and the walls? Even with skeleton fenestrations you can’t really clean without disassembly, can you? Or maybe I misunderstood your methods.

Your concern is valid. I heavily agitated the whole skeletonized barrel in IPA until the glued nut fell off. Then I wound the spring until slippage and repeated the cleaning process. 

4 hours ago, Knebo said:

I was also wondering about this. My initial understanding was the you'd apply D5 as a [wrong] breaking grease (i.e. to the barrel wall) for the 3rd test. But now I'm wondering if you did or not...

I filled the skeletonized barrel with D5 and let it soak for some minutes. Then I let the excessive oil drop out. So I was sure the oil reached the barrel wall.

Edited July 24, 2024 by Kalanag

[Knebo]

3 hours ago, Kalanag said:

I heavily agitated the whole skeletonized barrel in IPA until the glued nut fell off

I really don't know if IPA would remove heavy grease like that..

If it didn't, the following tests would basically be a repetition of the first.

 

Maybe lighter fluid/benzine in the ultrasonic cleaner would get closer to removing the original breaking grease. But even with that, I'd be sceptical without removing the spring. 

I guess (like me) you don't have a mainspring winder? Then you could do the test properly. 

Or at least gently remove the barrel lid without removing the spring. Then you could have a slightly better look at the residual breaking grease that may/not have come off. 

 

Anyway, I really congratulate you for taking on this testing. I think the results would be very useful. 

[Neverenoughwatches]

9 minutes ago, Knebo said:

Maybe lighter fluid/benzine in the ultrasonic cleaner would get closer to removing the original breaking grease. But even with that, I'd be sceptical without removing the spring. 

Some petroleum based solvent shifts it better than alcohol . Difficult to know how well the old lube is being removed and new lube distributed without taking the spring out. Over time things also change, testing in a working environment might show different results. We all love a good experiment, great idea like this help us all learn   

[RichardHarris123]

16 minutes ago, Knebo said:

really don't know if IPA would remove heavy grease like that..

If it didn't, the following tests would basically be a repetition of the first.

IPA won't remove the grease, at best it will dilute it, making it less viscous.  I really do commended you on your efforts but the experiment is flawed.  The only way to do it correctly would involve removing the spring and ensuring everything is perfectly clean before trying the next grease.  Once again, I  have nothing but respect for your efforts. 

[Kalanag]

On „multiple request“ I repeated the dry test after disassembling the barrel and cleaning with Naphta and rinsing with IPA.

The result was again 7 turns!

Edited July 25, 2024 by Kalanag

[Neverenoughwatches]

2 hours ago, Kalanag said:

On „multiple request“ I repeated the dry test after disassembling the barrel and cleaning with Naphta and rinsing with IPA.

The result was again 7 turns!

Just to confirm . 7 turns and the spring was completely wound or very nearly and then the bridle started to slip ?

[Kalanag]

8 minutes ago, Neverenoughwatches said:

Just to confirm . 7 turns and the spring was completely wound or very nearly and then the bridle started to slip ?

Right! See here:

Edited July 25, 2024 by Kalanag

[JohnR725]

On 7/23/2024 at 11:35 AM, Kalanag said:

The opening allows cleaning and lubricating the inside without removing the mainspring and risking a bent spring or bridle.

sometimes I hate the advertising on the message board as I read the original message and then saw the advertisement and didn't realize the conversation had continued with multiple people asking the exact same question that I had which is you can't properly clean the barrel without removing the mainspring.

2 hours ago, Kalanag said:

The result was again 7 turns!

you should try some P1 25 see if that makes any difference.

The other problem with the test is what is the purpose of the breaking grease? the other purpose of the breaking grease is when you reach the point of time that the mainspring slips how much does it slip? I remember using the wrong grease when I was in school I just grabbed the bottle out of the drawer it looked right and found that when the spring slipped it basically lost all of its energy. so the other purpose of all of this would be when it loses its energy I guess you're getting seven turns every single time which means we can throw away one more lubricant or basically not by another lubricant that we don't actually need.

Edited July 25, 2024 by JohnR725

[Kalanag]

3 hours ago, JohnR725 said:

…you should try some P1 25 see if that makes any difference.

The other problem with the test is what is the purpose of the breaking grease? the other purpose of the breaking grease is when you reach the point of time that the mainspring slips how much does it slip?…

I never bought this insanely expensive Gluber stuff. I always use the much cheaper PTFE grease that Jaeger le Cultre wants to be used in the 889 automatic which I wear every day. Using this grease in my testing setup provides 7 turns before slipping.

My method of winding gives a perfect feel of the slipping process in my fingertips. In all setups I could feel some fine vibrations when I wound the spring beyond the slipping limit. There was no loss of tension.

In the past I once had a bad mainspring which suddenly released at least one wind when reaching the limit. I could not only feel but even hear this sudden slipping and loss of power.

With my testing I found no difference in power reserve with the mainspring barrel dry, oiled or greased.

My conclusion is (for now), that braking grease does not significantly alter the braking force between mainspring bridle and barrel wall. So the power reserve of an automatic watch seems not to be significantly related to the lubricant.

Nevertheless the contact area between bridle and barrel wall is most likely the haviest loaded surface in a watch and needs a special grease containing PTFE, graphite or MoS2 to prevent premature wear.

Edited July 25, 2024 by Kalanag

[spectre6000]

I might have missed something... 

On 7/23/2024 at 12:35 PM, Kalanag said:

- barrel factory lubed => 7 turns +/- 10°

- barrel dry w/o lubrication => 7 turns +/- 60°

- barrel oiled with Moebius D5 => 7 turns +/- 10°

The difference is that +/-50°, right? The grease makes the full wind turn count more predictable, which I guess matters if you're trying to meet advertising specs for run time off a full wind (and why bother when the marketing wanks don't bother trying to meet their specs to reality?). Seems the actual reason for the grease is to protect the barrel so that it KEEPS being 7 turns and prolongs service intervals and component life. (In the event I missed something up there over the last two days or so that the thread has been going, please see my previous post and excuse me. That whole baby mollifying situation repeated last night/today.)

The test I thought would have been interesting in this would be a NON-braking grease vs braking grease. Every time I see the words "braking grease" it makes me wonder what about it makes it good for braking... Kinda like the friction modifiers used in clutch-based LSD differentials? Or something else?

Edited July 25, 2024 by spectre6000

[Kalanag]

1 hour ago, spectre6000 said:

…The difference is that +/-50°, right?…

Right for the dry barrel wall only! Leaving the barrel without lubrication is a bad idea though.

A side note: On Youtube you can find a professional watchmaker who mainly services contemporary automatic wristwatches. Having watched a dozen of his videos I found that he never removes the mainspring from the barrel. He just cleans the barrel with the mainspring inside and then oils it. This practice obviously has been working good enough so far to stay in business. That‘s not a surprise for me anymore.

 

Edited July 25, 2024 by Kalanag

[RichardHarris123]

28 minutes ago, Kalanag said:

services temporary automatic wristwatches.

What's a temporary automatic watch? 

[Kalanag]

17 minutes ago, RichardHarris123 said:

What's a temporary automatic watch? 

Sorry, I ment contemporary 

I just corrected it. Thank you!

Edited July 25, 2024 by Kalanag