Chime Rods: Tone Quality Improvement & Equalization

Discussion in 'Clock Repair' started by Betzel, Oct 7, 2019.

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  1. Betzel

    Betzel Registered User

    Dec 1, 2010
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    I apologize if this has been covered before, but I could not find anything on this when searching for a cure.

    This is about the musical/tonal quality resulting from restoring the surface finish on a chime rod that has become pitted via contact with something acidic (fingerprints, vinegar, solvents, etc.) or repaired after the leather fails and brass hits the chime metal-to-metal and the repairer has hammered, filed or sanded the rod and handled it (without cleaning afterwards) during the repair.

    So, I'm repairing a Junghans deco style wall clock (marked only 118 on the movement, and looking similar to a W202) with three chimes (High is A#4/466.16 Hz., Med is G4/415.30 Hz., and low is D#4/311.13 Hz.) The high is the "ding" and the two lows are struck together for the "dong." Maybe this is also called blim and blam? I'm new at this art, and not really sure.

    Anyway, the higher pitched, shorter rod or "ding" was off pitch and resonated with a dullish "thud" while the other two had a really nice (actually, awesome) harmonic sound. This had nothing to do with hammers, their positioning, the leather "heads," or the chime block, rod head screws or how it all connects to the wood of the case to resonate, though all these things are critical and were addressed as required. Fortunately, heat had not been used so the original hardening was still "rolled in" to these old chime rods.

    With the block out and clamped to the bench as a resonator, I struck each rod where the hammers usually hit with the butt of a wood brush I normally use to clear lathe chips, listening to the sound. After raising the pitch via filing maybe .25mm off the end so it rang at the correct frequency (half of the problem, and a lot like the sound of two engines running at very slightly different RPM's) it was still not as awesomely resonant-sounding as the other two.

    Looking at the two good rods (with original hammers), I noticed they were old, but still smooth and shiny along their entire length. The "thudding" rod had a non-OEM hammer, so was previously repaired and the rod had been mended to correct damage from hammer strikes (after the leather wore out). Then, his handling of the rod during the repair (but not wiping it clean) etched over time from acidic fingerprints, leading to the rest of the dull sound.

    So I finished off the otherwise fair previous repair with a fine file and some 2000 grit wet/dry while supporting the rod on the edge of a piece of wood, then burnished it all bright again with a steel rod and some oil using a light touch. Now, das ist wieder gut. Just like taking the rust off old guitar strings!

    I'll have to remember to wipe down all the chime rods in future repairs.

    Try this before replacing the block? Hope this helps someone, somewhere!
  2. shutterbug

    shutterbug Moderator
    NAWCC Member

    Oct 19, 2005
    Self employed interpreter/clock repairer
    North Carolina
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    :thumb: Thanks, Betzel! I've found that cleaning coiled gongs helps them sound better too.
  3. tracerjack

    tracerjack Registered User
    NAWCC Member

    Jun 6, 2016
    Lodi, CA
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    Did you use some type of agent to wipe down the rods or just a dry cloth? I have saved several broken chime rods for future attempts at repair. Seemed like a fun project to try regardless of success or failure. Naturally, they will not have their original sound since they must be shortened, but some of the rods are so superior in quality, seemed a shame to throw them away.

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