Is it time to replace the mainspring?

[Tmuir]

I've serviced several clocks before, but this is the first watch I've done.

The photo below shows the mainspring next to the barrel, the spring to my unskilled eyes looks to be slightly set and I'm wondering should I replace it?

Am I correct should the spring be replaced, or is this still ok? Appreciate some advice.

 

Thanks

Tony

[RyMoeller]

Honestly I can't tell by the "look" if it needs to be replaced.  I've tried and failed in the past.  The older blued steel springs will appear set simply because they don't have the S turn that new mainsprings have.

I usually decide on replacements based on the following:

1. Is the old one broken?
2. Is a replacement available?
3. How long will it take to remove the old one if I reuse it and discover it's got no life left?
4. How long will it take for my supplier to get the new one to me?
5. How much money do I have to spend?
6. Will I have to pay $10 shipping for a $15 mainspring?

(Obviously none of this is helpful but at least you know the internet still works)

Edited December 9, 2016 by RyMoeller
Grammar

[oldhippy]

That spring still carries its shape, so I think its alright and carry on with it. The coils have good distance between each other, they don't look tired its not out of shape so I think its fine.

[JohnR725]

Having seen people repair clocks before I'm always amazed that if this was a clock spring they would be extremely happy. Clock springs can look set at least from a watch point of view and still be very very acceptable.

Visually you can't tell by looking at the mainspring and you can't even go by the lack of the S-curve of the modern spring. I've seen blue springs original American factory springs have S-curve's and I've even seen some of the new White Springs look partially set visually you can't tell just by looking at it.

Then whose watch is this? In other words if you're doing this for a paying customer you would change the mainspring especially if it's blue. but if this is your personal watch I probably wouldn't worry about it.

There is a way to figure out if this is going to be a problem which is you put the watch back together with the spring. depending upon how badly set the spring is and whether it's even a functional spring at all will determine the running time of the watch and the amplitude. The amplitude will really be a problem at the end of 24 hours if you just don't have enough power to run the watch.

 

 

 

[vinn3]

that spring looks good.  kinks or rust are the things to watch for.  i came across a " lifetime main spring"  basically just twice as strong.  any one know about these ?  vinn

[jdm]

15 hours ago, vinn3 said:

that spring looks good.  kinks or rust are the things to watch for.  i came across a " lifetime main spring"  basically just twice as strong.  any one know about these ?  vinn

And did you installed it or just saw on a catalogue?

[vinn3]

not only installed,  took it out of the barrel.     merry Christmas

[JohnR725]

17 hours ago, vinn3 said:

that spring looks good.  kinks or rust are the things to watch for.  i came across a " lifetime main spring"  basically just twice as strong.  any one know about these ?  vinn

I'm curious about the twice as strong part? Was it actually printed on the package it's twice as strong where did that come from? the reason why I'm curious about twice as strong is increasing the strength of the mainspring it changes the amplitude of the watch. Quite a few watches if you put a double strength mainspring in you'd have too much amplitude which would be a problem. Then conceivably if this was a replacement spring for generic watch twice the strength would be thicker you would lose length which would cause a loss of running time so I assume this was a very specific watch?

There are watches that come with barrels that are sealed with the claim that there a lifetime or something equivalent. But I don't think watch companies ever grasped that lifetime for the watch could literally be hundreds of years.

So the early blued steel Springs they had a habit of breaking. Not necessarily the blued steel fault I suspect some of its from manufacturing. They break in a variety of locations the most interesting one is when the spring literally shatters into a whole bunch of pieces.

So right now I'm looking at the various labeling from a variety of mainspring envelopes common terms are unbreakable & non-setting  both quite common and one package even says guaranteed for the life of the watch.

[vinn3]

keep looking.   i bought  a  17 J elgin pocket watch for the mvt..  it was stiff to wind, but ran good.  after taking it out of the barrel,  my watchmaker friend ( bill)   said " its a lifetime spring "   put it back in.  vinn

[oldhippy]

If the spring isn't the old blue type and appears to be of the new type white metal it can be referred to as a lifetime spring also known as an unbreakable spring, depends on the manufactured label. But as you know all springs can and will break.  

[JohnR725]

The Elgin mainspring is a  Durapower Mainspring. to understand the Elgin mainspring I'm attaching a PDF.

So Elgin had their own special alloy other companies had other things the modern spring have similar characteristics to this. It's why they say their lifetime never do a whole variety of evil or bad things but they can still do those things. I've still seen modern white spring broken even set which of course from the literature is totally impossible.

So even though Elgin is specifically describing their modern nifty steel it still applies to the modern Springs. Basically the modern steel is stronger the same thickness.  This can be a problem though for older watches specifically designed to run with a blue spring the new white spring may have too much strength you will have over amplitude problems.

Elgin Durapower Mainspring.PDF

[Tmuir]

Thanks everyone.

I will reuse the spring.

[Jimbo]

16 hours ago, JohnR725 said:

They break in a variety of locations the most interesting one is when the spring literally shatters into a whole bunch of pieces.

 

I think watchmakers' lore says this happens during a powerful thunderstorm. Who knows.