As I recall, it was emphasized to us that the product is quite strong, to the
rated strength, in the axial direction, and was designed only for an axial
load. It was emphasized that load in other axes was expressly not recommended.
Clearly, in the 8' coil, the non-axial stresses were significant. This is a
relatively rigid material and coiling it, even in an 8' coil, can't be good for
it. -- KE3Q
----- Original Message -----
From: k3mm@comcast.net<mailto:k3mm@comcast.net>
To: towertalk@contesting.com<mailto:towertalk@contesting.com>
Sent: Monday, May 02, 2005 8:22 PM
Subject: Re: [TowerTalk] polyrod
We got NO official analysis back from the factory. They simply replaced the
coils we claimed as defective and we promised to uncoil them all as soon as
received to avoid a repeat.. It took a several months to receive our entire
order from start to finish the first time and it took a lot longer time and a
lot of phone calls,etc., to get it replaced. I got the impression they were
having production problems with our order at the time. Our rod was black 3/8",
mostly coiled in 8' diameters and covered in a split black corrigated drain
tube and cardboard. There was no sign of shipping damage on any of it. I
believe our total order ended up being over 15,000 feet or so.
I've already explained what I observed from our coiled rod...with the rod
fibers buckling on the inner radius from the tension imposed by the ones on the
outer radius exceeding the ability of the "glue" to hold the fibers together.
It was a gradual process, which allowed me to observe it happen in various
stages at different points in the coil. As the failure progressed, the radius
got tighter at the failure point, which accelerated the failure until the
entire rod had snapped, usually looking rather frayed at least part-way through.
Whether the "glue" from our batch was improper for one reason or another I
have no idea.
It's quite possible they have changed the resin used or had a bad mix in our
batch which made it softer or more susceptable high temperatures.
Tyler K3MM
-------------- Original message --------------
> >
> > My point exactly. It certainly DOES matter why it failed,
> > and it isn't up to customers to guess why.
>
> Agreed
> >
> > It could have been heat (they did warn me about heat, but
> > said it had to be a lot hotter than I ever would worry
> > about), it could have been over-bent (also cautioned me
>
> The summer sun on an unventelated, metal shed may create temperatures
beyong
> the those necessary for softening the resin (Vinyl Ester, or epoxy). A
> fiberglass airplane with a colored paint job, left outdoors in the summer
> sun even in Michigan will get far hotter than necessary to soften the
resin.
> When this happens to Vinyl Ester Resin it gets really strong and hard after
> cooling and it raises the critical temperature by quite a bit.
>
> > about that), but they keep saying storage while coiled isn't
> > an issue.
>
> I'd like to see someone run some tests on the stuff. Acellerated againg,
> using heat and UV as well as the appearance of some that has been exposed
to
> the elements for a few years.
>
> Do they have a site where you can look at the figures for the stuff?
> I have not been able to find anything on the web pertaining to polyrod, or
> Polygon as far as a guy line.
>
> >
> > I can't do a thing more than ask because the stuff laying
> > around here has been in coils laying outside for years and
> > is still in perfect shape. It would be a shame to have the
> > problem caused by something other than being in a coil and
> > not know what the real problem was.
> >
> If the stuff is light colored and laying outdoors *probably* the only
things
> to worry about are UV and moisture. If the outside is still smooth it
> sounds like it's doing well.
>
> > But then I've run into this in other areas (bad electrical
> > components like vacuum tubes and capacitors) and seen the
> > backlash so maybe I'm more sensitive to requiring accurate
> > answers....
>
> Having been a project manager for a large corporation when I retired, I'm
> also very sensitive about why something may have failed and the engineering
> specs for a product.
>
> It may be the best thing since sliced bread, but I still want to see the
> specs and any information on aging and failures.
> >
>
> 73
>
> Roger Halstead (K8RI and ARRL 40 year Life Member)
> N833R - World's oldest Debonair CD-2
> www.rogerhalstead.com<http://www.rogerhalstead.com/>
> > 73 Tom
> >
> > _______________________________________________
> >
> > See: http://www.mscomputer.com<http://www.mscomputer.com/> for "Self
Supporting Towers", "Wireless
> > Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with
> > any questions and ask for Sherman, W2FLA.
> >
> > _______________________________________________
> > TowerTalk mailing list
> > TowerTalk@contesting.com<mailto:TowerTalk@contesting.com>
> >
http://lists.contesting.com/mailman/listinfo/towertalk<http://lists.contesting.com/mailman/listinfo/towertalk>
> >
>
>
> _______________________________________________
>
> See: http://www.mscomputer.com<http://www.mscomputer.com/> for "Self
Supporting Towers", "Wireless Weather
> Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any
questions
> and ask for Sherman, W2FLA.
>
> _______________________________________________
> TowerTalk mailing list
> TowerTalk@contesting.com<mailto:TowerTalk@contesting.com>
>
http://lists.contesting.com/mailman/listinfo/towertalk<http://lists.contesting.com/mailman/listinfo/towertalk>
_______________________________________________
See: http://www.mscomputer.com<http://www.mscomputer.com/> for "Self
Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll
Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA.
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com<mailto:TowerTalk@contesting.com>
http://lists.contesting.com/mailman/listinfo/towertalk<http://lists.contesting.com/mailman/listinfo/towertalk>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
_______________________________________________
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