[CQ-Contest] Aluminum fatigue cracks and scratches - treatment?

[Kristinn Andersen]

Hi:

 

I just noticed a mild scratch close to the base of my vertical aluminum pole
that serves as a vertical antenna and support for an inverted-V.  This has
developed during the last year as a result of a friction against a steel
bolt close to the aluminum pole surface.  It appears to be tolerable, as
long as it does not develop further - I have relocated that steel bolt and
the pole is guyed so bending/fatigue movements should be minimal at this
point.

 

 

Years back I had an aluminum vertical that initially had a relatively
"innocent" scratch at the base, which developed into a crack as the vertical
swayed with the wind, and the unit finally broke.  A friend of mine advised
me afterwards that I could have prevented this fatigue development of the
scratch/crack by sanding and polishing it down so that there would be no
crack to propagate through the aluminum cross section.  Now, I am thinking
about doing this, but would like to hear if any of you have a comment on
this.  Sanding down the crack sure makes it disappear, but at the same time
I would be thinning the wall of the tube a little in this place.  Any
comments?

 

73 de Kris, TF3KX