Replacement Main Spring Quality

bchaps

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Not attempting to open a can-o-worms, but I would like to hear from you about "Replacement Mainsprings". In an earlier post Shutterbug said something like 'If it isn't broken, I don't replace it' (loose paraphrase). I agree with that idea but more due to quality and price of the current replacement springs I'm seeing. But, let's start with a broken spring.... Do you use the ~$7.00 Asian spring (Merritts) or hit your client for the ~ $18 spring which I'm assuming is of German origin? Have you experienced any cheap spring failure? In the past, I downsized to 0.165" because our newer steel was supposedly stronger than the old early 1900's quality. Is that still necessary if using the Asian spring? Years ago, I found a client on my doorstep with a bag of clock pieces. I apparently didn't get the spring center hole adequately formed to the arbor and in the middle of the client winding the spring, it let loose... fortunately disassembling the kitchen clock case cleanly along joint lines. I really don't want to repeat that experience again for any reason. So please, share what you are doing with clock mainsprings! Thanks, Bill
 

R. Croswell

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For a busted spring, try to avoid anything from India or Asia. If the supplier offers the same size spring on sale or at a bargin price as well as at a higher price, take the higher priced option and hope for the best. As for using a different thickness spring, if the spring being replaced is brass or what we commonly call wrought iron, a thinner modern spring will produce the same power. There are no absolutes as the property of the spring depends on the steel and how it is tempered. I recently replaced a broken 0.018” thick spring with a new 0.016” thick spring. It was coiled and tied with wire in a ’normal’ size package. When I untied it it rolled out almost as a long flat strip. it installed ok and the clock runs ok, but that spring is as stiff as any 0.018” thick spring. It seems that three springs from three sources may not all have the same properties or quality. It’s something of a crap shoot.

RC
 

shutterbug

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I agree with RC. I have had new springs from India break on the first wind. I just won't buy any more of them.
 
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Swanicyouth

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I just bought 2 new ones - odd sizes. They were $18 each. The came in a plastic bag, no idea coo. One of them the brass rivet holding the loop broke off as I took it out of the bag. The other was ok.

I drilled out that little hole & put in a much bigger aluminum rivet, because that is what I had.
 

R. Croswell

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I just bought 2 new ones - odd sizes. They were $18 each. The came in a plastic bag, no idea coo. One of them the brass rivet holding the loop broke off as I took it out of the bag. The other was ok.

I drilled out that little hole & put in a much bigger aluminum rivet, because that is what I had.
I think this may be an indication of the overall quality of that spring. Is this the type of spring that has a separate "loop end" riveted to the end of the spring, or one that has the end of the spring formed into a loop and riveted to itself? I prefer a solid steel rivet. I hope you didn't use an aluminum pop rivet, that would look nasty. I'm not sure that I would trust an aluminum rivet even of it is solid for this application.

RC
 
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Swanicyouth

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The spring is folded over at the loop with a very tiny brass rivet. Sometimes it’s just easier to use what you have, then trying to source one special tiny brass rivet. Probably not what I do with a clock worth thousands of dollars, but not the case with this clock.

But yes, quality isn’t great. I only replace a spring if the old one is broken or damaged.
 

Bohemian Bill

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Not attempting to open a can-o-worms, but I would like to hear from you about "Replacement Mainsprings". In an earlier post Shutterbug said something like 'If it isn't broken, I don't replace it' (loose paraphrase). I agree with that idea but more due to quality and price of the current replacement springs I'm seeing. But, let's start with a broken spring.... Do you use the ~$7.00 Asian spring (Merritts) or hit your client for the ~ $18 spring which I'm assuming is of German origin? Have you experienced any cheap spring failure? In the past, I downsized to 0.165" because our newer steel was supposedly stronger than the old early 1900's quality. Is that still necessary if using the Asian spring? Years ago, I found a client on my doorstep with a bag of clock pieces. I apparently didn't get the spring center hole adequately formed to the arbor and in the middle of the client winding the spring, it let loose... fortunately disassembling the kitchen clock case cleanly along joint lines. I really don't want to repeat that experience again for any reason. So please, share what you are doing with clock mainsprings! Thanks, Bill
Hi Bill..When I started about 25 years ago, I took all the local chapter clock repair classes and worked on many clocks. The general rule back then was replace all set mainsprings. So I was replacing all .016 thick with cheaper Japanese .018 strong. Later, when .0165 thick replacement loop end springs were available from suppliers, I started purchasing them. Then I started seeing a few main wheel teeth was burring out, which I had to remove and reverse the main wheel and finally restake wheel and click and install new .0165 thick springs. The past ten years or so, I notice here on this forum that many to most members are re-using existing springs if the spring is in good shape mainly due to the current purchase springs are not the quality of the old springs. Since, I have been acquiring many junk American movements which I have been using them for spare parts and also a supply of old loop mainsprings... Bill
 

R. Croswell

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Hi Bill..When I started about 25 years ago, I took all the local chapter clock repair classes and worked on many clocks. The general rule back then was replace all set mainsprings. So I was replacing all .016 thick with cheaper Japanese .018 strong. Later, when .0165 thick replacement loop end springs were available from suppliers, I started purchasing them. Then I started seeing a few main wheel teeth was burring out, which I had to remove and reverse the main wheel and finally restake wheel and click and install new .0165 thick springs. The past ten years or so, I notice here on this forum that many to most members are re-using existing springs if the spring is in good shape mainly due to the current purchase springs are not the quality of the old springs. Since, I have been acquiring many junk American movements which I have been using them for spare parts and also a supply of old loop mainsprings... Bill
Bill, I think part of the confusion comes from just what are "set mainsprings", and just what constitutes "if the spring is in good shape". A number of people have tried to define set mainspring, or repeated something they have heard based on how much it expands when removed compared to its fully wound diameter. Ironically the "good" springs you salvage from old clocks probably qualify under some definitions as being set. When a clock fails to run a lot of people here, especially beginners, assume that if everything looks ok to them that the mainspring must be "weak" or "set", but unless the spring is actually broken, it is probably OK.

It is obvious that old springs do not uncoil to the same diameter as never used springs, but why would we not expect that? Being "set" is more than just having a spring conform to the space it has lived in for the past 100 years. A real "set" spring is a defective spring that can no longer power the clock. But if we acknowledge that mainsprings can become set, I afraid that a lot of good old original springs will be replaced and then in a few weeks the original problem resurfaces......guess it wasn't set spring after all. The advice I now give is unless it is broken the spring is probably OK if the clock runs for the period it is supposed to run when the rest of the clock is in good order.

As far as identifying a real set spring, I think it's like the judge who was asked to define pornography. He said he couldn't define it but he knows it when he sees it.

RC
 
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Bohemian Bill

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Bill, I think part of the confusion comes from just what are "set mainsprings", and just what constitutes "if the spring is in good shape". A number of people have tried to define set mainspring, or repeated something they have heard based on how much it expands when removed compared to its fully wound diameter. Ironically the "good" springs you salvage from old clocks probably qualify under some definitions as being set. When a clock fails to run a lot of people here, especially beginners, assume that if everything looks ok to them that the mainspring must be "weak" or "set", but unless the spring is actually broken, it is probably OK.

It is obvious that old springs do not uncoil to the same diameter as never used springs, but why would we not expect that? Being "set" is more than just having a spring conform to the space it has lived in for the past 100 years. A real "set" spring is a defective spring that can no longer power the clock. But if we acknowledge that mainsprings can become set, I afraid that a lot of good old original springs will be replaced and then in a few weeks the original problem resurfaces......guess it wasn't set spring after all. The advice I now give is unless it is broken the spring is probably OK if the clock runs for the period it is supposed to run when the rest of the clock is in good order.

As far as identifying a real set spring, I think it's like the judge who was asked to define pornography. He said he couldn't define it but he knows it when he sees it.

RC
Good explanation of a set mainspring RC..I wish I could have said that...
I would like to add that I would replace the mainspring if the spring have visible rust pits or visible cracks that the cracks would catch the steel wool strands while cleaning or if the mainspring is rough to the touch after cleaning. I had a few mainsprings in the past that was dull grey to black after cleaning and rubbing with steel wool and solvent and it was not slick and smooth like glass. I was afraid to use the mainspring that it would not provide constant smooth power without sticking or jumping while expanding even with lubricant. Most of the smooth good mainsprings that I experienced after cleaning would either be shiny silver, light brown or blue in color.
 

R. Croswell

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Good explanation of a set mainspring RC..I wish I could have said that...
I would like to add that I would replace the mainspring if the spring have visible rust pits or visible cracks that the cracks would catch the steel wool strands while cleaning or if the mainspring is rough to the touch after cleaning. I had a few mainsprings in the past that was dull grey to black after cleaning and rubbing with steel wool and solvent and it was not slick and smooth like glass. I was afraid to use the mainspring that it would not provide constant smooth power without sticking or jumping while expanding even with lubricant. Most of the smooth good mainsprings that I experienced after cleaning would either be shiny silver, light brown or blue in color.
In the mid 1800's a number of clock makers used what we generally refer to as wrought iron springs. The surface is rough and dark and the springs tend to be on the heavy side. They look "set" when there is nothing wrong with them. I tend to use grease on these and mostly the run just fine. I guess the clock maker took into account the limitations of the springs and specified ones that were adequate. When replacing these one generally uses a modern spring that's a little thinner.

Any cracking or serious rust pitting and I call it defective and replace it. The one thing I am not sure what to do about is when a clock comes in with two original mainsprings and one is busted. Should I preemptively replace both, or just replace the busted one? Time was when I recommended replacing both, but with spring quality the way it is now I'm not so sure.

RC
 

Bohemian Bill

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In the mid 1800's a number of clock makers used what we generally refer to as wrought iron springs. The surface is rough and dark and the springs tend to be on the heavy side. They look "set" when there is nothing wrong with them. I tend to use grease on these and mostly the run just fine. I guess the clock maker took into account the limitations of the springs and specified ones that were adequate. When replacing these one generally uses a modern spring that's a little thinner.

Any cracking or serious rust pitting and I call it defective and replace it. The one thing I am not sure what to do about is when a clock comes in with two original mainsprings and one is busted. Should I preemptively replace both, or just replace the busted one? Time was when I recommended replacing both, but with spring quality the way it is now I'm not so sure.

RC
RC...I have not figured out how to recognize if the mainsprings is original or replacement
? But I have seen that Seth Thomas stamped their original clock mainspring "ST" on the loop end bracket. I have not seen any other manufacturers mark theirs? Do you have any tips or experience in recognizing original mainsprings for the other?
I am assuming most mainsprings have been probably been replaced during repair probably during the 1940s to 1970s. My wife and I watch a lot of good movies in the late 1930 thru the 1950s. I notice a lot of working clocks on the mantles and wall hanging clocks in the old movies during this period. The newer movies most clocks are just wall hangers and not working. Bill
 

R. Croswell

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RC...I have not figured out how to recognize if the mainsprings is original or replacement
? But I have seen that Seth Thomas stamped their original clock mainspring "ST" on the loop end bracket. I have not seen any other manufacturers mark theirs? Do you have any tips or experience in recognizing original mainsprings for the other?
I am assuming most mainsprings have been probably been replaced during repair probably during the 1940s to 1970s. My wife and I watch a lot of good movies in the late 1930 thru the 1950s. I notice a lot of working clocks on the mantles and wall hanging clocks in the old movies during this period. The newer movies most clocks are just wall hangers and not working. Bill
I know this sounds odd but old springs look”old”. There will be wear marks especially noticeable if the springs were heat treated to blue. Mismatched springs let us know that at least one is not original. ST is the only brand. I recall being stamped

RC
 

Swanicyouth

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I had a New Haven spring that when uncoiled to clean it, just did not want to coil back up how it should, it want to twist itself all around, that I replaced. I’ve also had some that were very difficult to clean even with steel wool & mineral spirits. Black spots of old grease embedded in the metal. I found that Brake Kleen made the job significantly easier
 

R. Croswell

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I had a New Haven spring that when uncoiled to clean it, just did not want to coil back up how it should, it want to twist itself all around, that I replaced. I’ve also had some that were very difficult to clean even with steel wool & mineral spirits. Black spots of old grease embedded in the metal. I found that Brake Kleen made the job significantly easier
I put springs in something called “Super Clean” from Wal-Mart automotive department. It’s a strong purple stuff. The original contained lye, the current stuff not as much but still caustic. Use full strength. Lye won’t bother steel but will eat brass and grease. Just leave the spring soaking for 24 to 48 hours. Usually just wipe, rinse, dry immediately. May not need to do anything else.

RC
 
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demoman3955

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I had a New Haven spring that when uncoiled to clean it, just did not want to coil back up how it should, it want to twist itself all around, that I replaced. I’ve also had some that were very difficult to clean even with steel wool & mineral spirits. Black spots of old grease embedded in the metal. I found that Brake Kleen made the job significantly easier
2 days ago i had a new haven spring break, and it broke into many pieces and in the middle of the coil. I guess that was a good place to break, because the outer half kept it from tearing anything up.
 

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