My Fault?

[dagwra]

I was cleaning a Sessions 8-Day mantle clock mainspring and when I wound it to replace the mainspring clamp, it broke. I wound it fully until it wouldn't wind any more and thats when it snapped. I like to wind them all the way to the end to be sure the arbor is seated in the spring. Maybe I shouldn't do that? The spring snapped about 2 coils from the end.
Is this my fault that the spring broke or could it be that it eventually would have snapped anyway? I was using a mainspring winder but I don't feel I put undo pressure on the spring.
As always, thanks for your thoughts...

 

[bcaclock]

Hi, If this is a customers clock be glad it happened to you not them. It is common for a spring to snap when it is wound if it is ready to break, it was not your fault, it would have snapped soon anyway.
Bob

 

[shutterbug]

Unless you were applying unreasonable pressure, the spring was bad - probably had a crack that you didn't notice. This is definitely the place you want the spring to break if it's going too, because it won't do the damage it would in the clock (and it helps understand why gloves are recommended when working with springs). This is also why many just replace the mainsprings instead of cleaning them. The practice of winding them all the way is good. Remember that the spring winder does have the potential to apply more force than springs are designed for.

 

[Kevin W.]

Dagwra if you have a mainspring winder you can wind it up and release tension a number of times.At least if it breaks then it is on the winder.I dont have a winder but would do this if i had one.I had a mainspring break after just one month.

 

[harold bain]

Dag, you were lucky to have it break on the winder, saving the movement from possible damage. Veritas, if your spring broke in a month, it was likely a cheap India made one, which is why spending a few extra bucks on a spring is better than being cheap.
Harold

 

[Kevin W.]

Harold my spring was German made from a Canadian outlet.I asked for a refund and they told me no, as they have no idea if it will happen or not.I have bought springs before from the same place and it did not happen before.Mine broke a few turns away from the arbour.

 

[harold bain]

Veritas, it's attitude like that from our local "Canadian Supplier" that has sent all my business south of the border
Harold

 

[Paul Faf]

To me it seems all spings can fail. I have also had german and american and India spings brake. I think it all depends on the Tech who anneals the inner few inches before coiling.

I no longer Guarentee mainsprings.

The size of the wind key and the strength of the turning hand plays a part in failures.

Springs can be trained. That set spring you just pulled is proof of that. As others mentioned I use the mainspring winder and coil loose then back up then wind a little tighter an on and soforth

Lets not even get into talk about press notched arbor hooks. I'm guessing the guy that came up with that brain storm is long passed away. And looking down on us laughing.

Happy Thanksgiving Clock lovers

 

[Kevin W.]

I see where you are coming from Harold.Maybe if more people do it , it will hurt this supplier more.
A Happy Thanksgiving to our friends south of the border.

 

[Len Lataille]

You guys have pretty much covered any ideas that I could suggest. New springs, old, they can break at any time. And do be careful with a winder. One time I wanted to be sure that a spring was well hooked and put extra pressure with the winder. I dont have any muscle to speak of, but when the spring still would not hook, I took a close look and I had already cracked it in the inner coil.
I almost always replace springs, unless they look very new and open wide. In all cases, I open the spring and run a terry cloth rag along the edge, as far a possible. If there is a crack, the cloth will catch. Running a finger nail works also.
Also, examine any new springs carefully. Dont assume that because they are new, that they are flawless. And I've had this problem with springs from every country and every supplier, with pits and full length scratches.
Like food, "when in doubt, throw it out". The cost of that wasted spring (suppliers seldom refund as you and I have learned) is a lot less than the damage it can do to the clock and your reputation, including having a customer with a sore hand.