Damaged mainspring

[PostwarO27]

I was rewinding an automatic mainspring with an old K&D126 winder and when removing the winding stem from the barrel, the spring turned into a jumbled mess.  I untangled it and this is what it now looks like.  Is this salvageable or should I just get a new one?

[Plato]

It's knackered.

[mikepilk]

6 minutes ago, PostwarO27 said:

I was rewinding an automatic mainspring with an old K&D126 winder and when removing the winding stem from the barrel, the spring turned into a jumbled mess.  I untangled it and this is what it now looks like.  Is this salvageable or should I just get a new one?

 

I assume that you're not posting that as a joke!  

It's total trash. There should be no kinks, it should be smooth continuous curves, and flat.

[PostwarO27]

Actually, its a serious question.  I'm fairly new to the hobby and curious to know if there are any methods used to flatten a spring such as running it thru a roller similar to a slip roller for sheet metal.  I've removed kinks from constant tension springs for old window assemblies using a slip roller.  Of course those are much heavier gauge steel than the watch spring is but....

Anyway, I'll consider it toast and order up a new one.

[mikepilk]

19 minutes ago, PostwarO27 said:

Actually, its a serious question.  I'm fairly new to the hobby and curious to know if there are any methods used to flatten a spring such as running it thru a roller similar to a slip roller for sheet metal.  I've removed kinks from constant tension springs for old window assemblies using a slip roller.  Of course those are much heavier gauge steel than the watch spring is but....

Anyway, I'll consider it toast and order up a new one.

Sorry, I was being facetious.  

I don't see why you couldn't smooth out the odd kink, I've done it. But near the arbor end, it looks totally out of shape, and coned upwards, which is not easy to fix. The other end looks OK though !

[watchweasol]

To quote Plato "Its Knackered"  so you will not do any damage trying to salvage it as an exercise . But re fitting it into a watch is a no no as there would be no smooth power delivery.

[JohnR725]

1 hour ago, watchweasol said:

But re fitting it into a watch is a no no as there would be no smooth power delivery.

In addition to the visual look if you run the mainspring through your fingers can you feel the bumps and imperfections? If it's your own personal watch you try to straighten it out but even if you get everything straight if you can still feel the imperfections that's not good.

Then there's the problem of if it's bent now and you straighten it out is it more likely to bend again when you put it back in the wider? When you're using a mainspring winder you have to be very careful that you don't have one that's too small and physical size and you put too much pressure on the mainspring otherwise you get imperfections like this.

In real life the best thing to do would be to replace it.

[PostwarO27]

John,

Ideally I want to learn to do the proper thing when doing a teardown and rebuild.  If there were a way to fix the mainspring similar to Mark's videos for fixing hairsprings, i'd give it a try if there was a method to it.  The feedback I'm getting here and not being able to find any videos or related articles on fixing mainsprings I've already placed an order with Cousins for a new spring.

Thanks all!

[JohnR725]

30 minutes ago, PostwarO27 said:

f there were a way to fix the mainspring similar to Mark's videos for fixing hairsprings, i'd give it a try

The hairspring comparison is interesting because I was thinking about that? The difference is on a hairspring there isn't a lot of force on the hairspring other than when the watchmakers doing something bad to it. The mainspring has a lot of force in itself and when you're inserting it. So getting it all straightened perfect isn't's entirely an option unfortunately. But you still have nothing to lose you could try might as well have fun with it see what happens.