We Just Dyed a Little

Some bells crack – particularly very old bells that have survived the worst harm that centuries, Civil War, and exposure to the elements may impart. Such is true for the bell at Georgetown Lutheran Church, which the National Bell Festival in collaboration with B.A. Sunderlin Bellfoundry is working to restore. 

No one is quite sure when the crack to the 1780 bell first appeared and, until today, nobody knew quite how large the crack truly was. After a thorough visual inspection of the bell by technical specialists at the foundry, it was decided that a liquid penetrant test was needed to discern the extent of the fissure.

Liquid or dye penetrant testing is a tool bellmakers use to detect surface-breaking discontinuities, or cracks, in bells. When compared with a visual inspection alone, this test illuminates in finer detail the hairline cracks and micro surface fissures that weaken the structural integrity of a bell. Bronze and iron bells are quite strong, but when hit with enough force, like a hearty swing or clapper strike, a small crack can quickly expand into a break or complete shatter.

To perform the test, the area around the inspection site is cleaned of debris and surface irregularities. After drying completely, a highly-visible red dye is sprayed or brushed onto the bell, which absorbs into the surface. Any excess dye is removed and a developer is then applied to draw the penetrant back to the surface. The high contrast between red dye and white foam clearly distinguishes cracks and defects.


 
Dye penetrant testing clearly distinguishes the extent of the crack traveling up the Georgetown Lutheran Church bell.

Now that we have a more complete picture of the bell’s current condition, work can continue on the repair and restoration of this piece of American history. Much more to come!

 

Georgetown Lutheran Church

This article is part of a curated series on our work to restore the bell at Georgetown Lutheran Church in Washington, D.C. Continue exploring:

The National Bell Festival would like to thank B.A. Sunderlin Bellfoundry for their exceptional work in preserving this bell of historic importance.