In Service Product Failure

One of the most common problems that I have addressed over the years is in service product failure.  The problems range from buckling/cracking of wood flooring to failure of utility poles, chairs, decks, fences, bleachers, roofs, deer stands, ladders, etc.   The first question we must determine is a big one.  Is this a manufacturing problem or improper use/application problem.  I have seen instances when it is clearly one or the other and in some cases both.   As a consumer/user we can’t do much for products that are improperly designed and/or manufactured.  However, we can educate ourselves to try to buy the right product for the job.

The second question we must determine is also a biggie.  Was the product inspected and/or maintained over time?  If so, who did it?, What did they do?  What were their credentials?  Was a standard operating procedure being used to determine the nature and frequency of the inspection?  What documentation do we have? 

One example of improper design was a bar stool that was very tall with three small legs that were connected with glue.  An insufficient amount of glue was applied creating what is known as a starved glue joint.  It was inventible that the chair would eventually fail and it did. 

Photo of glue joint – courtesy USDA Forest Service

The interaction of wood and glue is important to develop a good bone and avoid product failure.

Poles that fail in service are carefully examined to determine if it was properly manufactured, type of preservative used, wood species, name of treater, year of last inspection, and pole class.  Then records are evaluated to determine the frequency and scope of inspections.  (Courtesy Dr. H.M. Barnes, Mississippi State University)

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