> This was our first opportunity to compare the results to existing white
> antennas. Look at Picture #140 and find the 3 antennas. Then look at the
> zoomed picture #139.
And the link to the photos is where?
I spend a lot of time working with fiberglass, epoxy, and vinly ester
resins.
I don't know where you are located, but the reason most fiberglass is
painted white is to keep the temperature down. That's why most fiberglass
airplanes are white. Darker colors will raise the temperature to the point
of the resin softening and sometimes losing structural integrity which does
not bode well for airplanes or antennas. Some resins and epoxies will stand
temperatures between 100 and 200 degrees higher than others. It all depends
on what was used in the antennas, but in general you don't want them to get
too hot to touch. Many are also very sensitive to UV exposure. I think the
softening point for regular epoxies is around 200F (give or take a tad) so
if you are in an area that gets lots of sun and partucularly the South and
South West the darker colors may not be a good idea. Up here in the frozen
north they'd probably be safe with the exception of a few summer days.
Still, all fiberglass needs to be protected by a good UV blocking
paint/coating.
BTW, I've not found a fiberglass element yet, that does not deteoriate over
time. Even the big motorola comercial repeater antennas eventually age. The
Diamond and Comet antennas (I have several of both) age much faster. Handle
one that's been out in the elements for four or five years and your hands
end up covered with a white powder.
Roger (K8RI)
>
> Tom
>
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