Spring Barrel Repair

Discussion in 'Clock Repair' started by matthiasi, Apr 16, 2014.

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  1. matthiasi

    matthiasi Registered User

    Dec 3, 2010
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    I've got an antique mantle clock in for repair that has definitely seen some better days.

    Signs of a previous mainspring failure are that around 5 teeth were taken out of the 2nd wheel on the chime side, which a previous repairman repaired by drilling a few holes radially and substituting 2 or 3 metal pins/missing tooth to act as gear teeth. These were hard soldered, with subsequent metal damage and discoloration of the wheel. I will leave this as-is, as it is functional and the client does not wish to have this repaired.

    So, my present dilemma:
    1. All three mainsprings have broken/torn ends. Two of them on the outer ends, one on the inner. I am replacing all three springs as the metal is getting brittle in other areas as well.

    2. One spring end has been torn & peeled back within 1/32 of the spring's end. By peeling back, it has also cracked the stamped tang-style spring hook to the point that it was also barely hanging on. As a matter of fact, it broke off whilst removing the spring!

    What would you use to make a new spring hook (tang style)? How?
    Or would you fabricate a steel hook (round, nail-head style) and rivet this into the barrel?

    Thanks for your input.
     
  2. dAz57

    dAz57 Registered User

    Dec 7, 2011
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    I would make a steel hook rather than cut the barrel for another tang hook, I did have a lovely barrel in last year where the orginal tang hook broke off, then someone attempted to bash another hook in the barrel (the dents in the barrel below the old tang hook) but only suceeded in denting the barrel, finally they just sawed the old tang hook longer, I just made a new rivetted hook on the other side after cleaning up the mess

    HAC Barrel mess.jpg
     
  3. Bruce Alexander

    Bruce Alexander Registered User
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    #3 Bruce Alexander, Apr 16, 2014
    Last edited: Apr 16, 2014
    I've found the need to replace Barrel Hooks is a pretty commonly occurring repair. I use a method outlined in the "Clockmakers Newsletter Workshop Series" as submitted by Gordon Ledford in July of '95.

    He recommends starting with size 12 miniature drill rod (0.### " diameter) to make a custom steel rivet.
    You turn the rivet so the measurements are (diameter x height):
    Head 0.### " x 0.025"
    Middle 0.145" x 0.035"
    Rivet 0.113" x 0.090"

    I'm not sure why the text editor keeps substituting "###" for "1 8 5" Above, but I hope this makes it clear. It should read one-hundred, eighty-five thousands of an inch. Geez!

    You then use a #33 drill bit to drill a new hole through the barrel wall; place and peen the rivet securely.

    The length measurements may need to be adjusted slightly to fit a thinner, or thicker barrel wall, but the measurements given usually work well.

    Ledford recommends that you always drill a new hole for the replacement hook. I'll usually turn a brass "rivet" to plug the old hole but it's not necessary.

    I've only been using this approach for a couple of years but these are strong, tight-fitting rivet/barrel hooks which have worked well for me so far.

    P.S. I definitely agree with dAz57 and would not try to "punch" a new hook in the barrel or modify the existing remnant of one.
     
  4. R. Croswell

    R. Croswell Registered User

    Apr 4, 2006
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    Yes, I would do as Bruce said for the hook. My concern is about the nail teeth. Unfortunately the next person to work on the clock is going to blame the last person to work on the clock (you) for every past incorrect repair. Nails don't usually work well as teeth and can cause early failure of the mating part. Can we possibly. See a picture? My policy is if I can't fix all that's wrong with a clock then I won't fix it at all.

    RC
     
  5. shutterbug

    shutterbug Moderator
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    I suspect that you aren't really talking about a barreled spring. The repair can be similar though. You can drill a hole through the arbor, and either thread it for a bolt reshaped at the head for a hook, then peened into place or you can use a shouldered rivet or even a shouldered nail peened like a rivet. Just fashion the head into a new hook. Somewhere in the archives is a very good tutorial on how to do that repair by David LaBounty.


    Going back to your title, maybe you ARE talking about a barrel. Anyway, here's the article I mentioned. It will help either way.
     
  6. bangster

    bangster Moderator
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    Here's a procedure recommended by John Hubby.

     
  7. matthiasi

    matthiasi Registered User

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    Thanks for the replies so far. I thought that I'll attach a couple of pics to clear things up a bit.
    I was also tending to go the route of the shouldered screw / drill rod method, but was interested to find out how you guys go about making the tang.

    I know it ain't easy... Little troublesome getting a jewellers saw in there, filing it out / using a cutting wheel (a la Dremel Diamond wheel) or a small burr is a mess. However, there must be a "proper way" short of setting up our own punch press...

    See pics for details. Yes, it is a barrel. The inner arbor is serviceable. I love the previous repair job...
    I am replacing all 3 springs for obvious reasons.

    One thing I always do is take plenty of pics, before & after. I also advise a client when I discover this type of mess or hidden problems. then I give them a copy of the pics before & after. Need to protect my rear end.

    However, if the client does not wish to do a proper repair and or restoration of an area, then I will still do the job with the caveat of not guaranteeing that portion. I know its' not the ideal way, however; in this day and age economy, clients are not always willing to pay for your time. So in this way, I look at it in a similar way as a garage would with a clients vehicle- do the agreed upon workscope and if its' safe, then let it go out the door.

    P1070169s.jpg P1060946s.jpg P1060938s.jpg P1070161s.jpg P1070167s.jpg P1070168s.jpg
     
  8. Bruce Alexander

    Bruce Alexander Registered User
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    The "tang" spring hook is one area where I wouldn't mind deviating from the original. It just seems like a manufacturing short-cut to me. They reduced steps and materials.

    I saw that leaf pinion repair in the "Hall of Shame" post. It looks like this clock's been "hacked" by one or more mechanically inclined amateur(s) along the way. Kept it running but the costs for proper repairs kept growing too. I can see where the current owner might have to prioritize your work.
     

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