The 5’s staple bolt nut, still rusted in place

Tapping a face of the nut with a hammer and flat punch, to set up vibrations and help the oil penetrate

The 5’s staple bolt nut continues to be rusted in place, despite a week of patient measures.

The nut is periodically heated using a propane torch, so that its slight expansion opens further gaps for the oil

The upper or lock nut was also rusted but was loosened much more easily, and after a thorough brushing and clearing of the threads it turns freely on the staple bolt.  The lower nut that supports the weight of the bolt and clapper is proving a problem.

Wrench on lower nut

The recommended approach for a rusted nut is:

  1. Apply penetrating oil periodically (in this case, daily since Feb 1 and twice daily most days).
  2. Tap the nut to set up vibrations that may help the oil penetrate the boundary between the bolt and the nut.
  3. Apply heat to the nut to expand it, to help the oil penetrate.
  4. Try to rotate the nut, either looser or tighter, using a pulsing force on the wrench.
  5. Patience:  penetrating oil works slowly.  Don’t make things worse by breaking or damaging the bolt!

Clapper tied up, and secured against counter-clockwise rotation with a jig clamped to the soundbow

All this is particularly important for a nut stuck on an expensive bolt like a bell’s staple bolt.

The jig, viewed from below; strips of tape are to show whether the jig slips and the clapper moves

In order to prevent damage to the twiddle bolts when trying to turn the stuck nut, the clapper has been tied up and blocked in place with a jig clamped to the soundbow, once the clapper bolt has been turned to an angle at which it is has enough free play.  One jig has been used so far.  A second one is planned so torque can be applied to the stuck nut first one way, then the other.

After ten days of this process we are wondering if the nut can be freed at all, or whether it is so firmly rusted on that it will never turn.

The jig to block the clapper from rotating

The next step, if the current measures don’t succeed fairly soon, is to support the clapper and staple bolt from below and cut the nut with a hacksaw, being careful not to damage the bolt’s threads, then free the pieces of the weakened nut with a wrench or a punch.  The cut(s) will go across a corner of the nut.

We’ve located at least one domestic source for replacement nuts of this size (20mm diameter, 2.50mm thread pitch).

All this only emphasizes the need to stop water from leaking into the bell chamber.


1 thought on “The 5’s staple bolt nut, still rusted in place

  1. Pingback: The 5′s staple bolt nut: work continues | miamibells

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