junghans barrel repair

Discussion in 'Clock Repair' started by itbme1987, Mar 16, 2011.

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  1. itbme1987

    itbme1987 Registered User

    May 18, 2008
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    Well of course it would have to happen after everything else was going so well, the tab that the mainspring hooks onto broke when i was putting the spring back into the barrel. What would be a good repair for this short of a replacement? I have read on placing the new hooks on the opposite side of the old one so thats all marked, my idea is to drill a hole in the barrel, then make a brass screw and screw it in, then file and pean the outside of the screw and then file the screw head into more of a hook on the inside, would this be an acceptable repair for this since the other one was more of a tab then a brass rivet like in some. Thank you 87106.jpg
     
  2. Willie X

    Willie X Registered User

    Feb 9, 2008
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    Sounds like a pretty good plan but best to use a steel rivet with a flat top, a slightly stepped rivet is easiest to work with. Any shaping of the hook has to be done before you peen it into place; the round head alone is fine, as long as it is not to big. Be sure to make the hole a tight fit and chambfer the outside edge so the peening will have something to hold on to.

    Studying some higher quality barrels will show you what needs to be done and a good clock repair book like
    DeCarlo covers this job in great detail.

    Good luck, Willie X
     
  3. harold bain

    harold bain Registered User
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    Never thought of using a rivet, Willie, but it sounds like a good repair. I've always used a small countersunk machine screw, shaped the head, threaded the hole, screw it in, cut it off, and peen it. With this type of a hook, a new hole 180 degrees around the barrel is the way to go.
     
  4. Mike Phelan

    Mike Phelan Registered User

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    I do what Harold does, as it's easier than turning a rivet.

    The original hook is a cheap idea and always fails sooner or later.
     
  5. itbme1987

    itbme1987 Registered User

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    How big of a screw would you suggest?
     
  6. harold bain

    harold bain Registered User
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    I use about a 6 or 8/32. Do you have a set of taps? Drill the hole smaller enough to be able to thread it.
     
  7. itbme1987

    itbme1987 Registered User

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    I do have a set of taps but only metric sizes
    -> posts merged by system <-
    I should mention this is the chime barrel
     
  8. harold bain

    harold bain Registered User
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    Go with the larger size, Ryan. Maybe your local hardware store might have a tap of the right size, to match whatever screw you can find there.
     
  9. itbme1987

    itbme1987 Registered User

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    I do have an assortment of machine screws from harbor freight and i think i do have a tap that will work with them, ill try it tomorrow
     
  10. bangster

    bangster Moderator
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    After peening, you can use a Dremel cutoff wheel to trim the near and far sides of the head. Narrower hook, to better fit the hole in the spring.

    :Party:
     
  11. itbme1987

    itbme1987 Registered User

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    well i think i got the repair down, I took a machine screw and found a tap that matched the threads of the screw, marked and center punched the spot then drilled the hole and tapped it, put a chamfer on the outside of the hole, then using a grinding attachement on my dremel i shaped the head to how i thought would work good, put the screw back, i pounded some solder into very very thin flakes and put a piece near the head and melted it for a little extra holding power, then used a cut off wheel and cut the extra off and peaned it on the outside then filed a little down and i think thats about it for the repair, it seemed to hold for a couple of times when i wound it fully.
     
  12. harold bain

    harold bain Registered User
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    Sounds good, Ryan. When peening, I find a hammer head close to the ID of the barrel, clamp it in a vice, put the barrel over it, and hammer the screw end. Never had a failure yet.
    Solder isn't a bad idea.
     
  13. itbme1987

    itbme1987 Registered User

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    guess great minds think alike, i have the staking set from merritts and i used the round anvil that came with it in the bench vice sideways and hung the barrel off it while peening
     
  14. bangster

    bangster Moderator
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    Here's what I use to support the barrel while peening the screw end.

    87520.jpg

    :D

    bangster
     
  15. Dave B

    Dave B Banned

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    Nice anvil, Bang! 100 pounder?

    I imagine the step is handy for forming the cleats on the shoes. :D
     
  16. bangster

    bangster Moderator
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    #16 bangster, Mar 22, 2011
    Last edited: Mar 22, 2011
    No, it's a big 'ern. Probly 150-180 pounds. 22inches long. I normally only use it for sharpening trunk lids.
    87629.jpg
    bangster
     

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