Posted by: AAPGAI | November 26, 2015

Do carbon rods slow down with use and age?

Reproduced with kind permission of Ron Holloway

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Do carbon rods slow down with use and age? If so, is it significant?

The Long Answer from my friends at SAGE –

Historically this was not an uncommon phenomenon experienced in well-used fiberglass blanks. The initial stiffness eroded due to lower fatigue strengths of the composite materials due to 2 primary factors:

1. The woven fiberglass fabrics inherently have multi-directional fiber orientations which are not aligned straight. In a weave yarns are bent as they cross over and under alternating yarns at various angles. When loaded non-linear fibers tend to straighten and have to move an extra distance compared to a fiber that is positioned straight from the onset. This puts an extra load on the fiber-resin bond.

2. Early pre-finishes (the chemical link between the glass fiber and the pre-preg resin) and resin systems had lower bond strengths compared to the resins used today.

Materials and designs used in Sage blanks have extremely high fatigue strengths and will not “soften” or loose their properties with extended use. This is due to:

1. Selection and use of high performance-high strength quality graphite fibers that have excellent mechanical and resin bonding properties (not all graphite fibers are equal in this area).

2. Sage’s exclusive resin system was developed to optimize the resin-fiber bond with high mechanical strengths. Our resin performance far exceeds typical sport grade resin systems.

3. Blank designs and material lay-up techniques that optimize fiber positioning. The fibers are oriented as straight as possible in the direction of the load. This maximizes strength and reduces strain on the resin-fiber bond.

The Short Answer

Today’s modern carbon epoxy rods have outstanding mechanical and fatigue strengths that far surpass the loads they will experience in a lifetime of use. Because of this their stiffness (action) should be maintained and will not soften over time.

The Shortest Answer

No.

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