[TowerTalk] pultruded/polygon rod

[jimlux]

On 3/6/18 10:08 AM, Steve Baughn wrote:
> Wanted to pick some of the experts’ brains on the use of fiberglass rod for guys such as strength and durability/lifespan. I am considering using this for a tower project. Was originally looking at phillystran but for the heavy duty stuff it is price prohibitive here. Any thoughts, suggestions,  etc on what to look for or ask about appreciated.
> 

glass/polymer composites are well characterized structural materials - 
in the "along fiber" direction (which you'd be using for guys) they're 
fairly high modulus.  In the "cross fiber" direction (bending), they're 
about half the stiffness of aluminum and comparable strength to aluminum 
for a given size.  That is, if you have a aluminum I beam that sticks 
out 10 feet, and you load it so that it deflects 6", the pultruded 
fiberglass will deflect about 12".  The "failure load" is about the same.

I've not tried to buy lengths longer than 20 feet, but I would imagine 
it's available.

You can get epoxy to bond sections together that has a strength greater 
than the underlying material, so pretty much anything you could do with 
Aluminum and a TIG, you can duplicate with composites and glue<grin>

I've bonded some stuff, and just used bolts for others.

There's several kinds, depending on whether it's fire retardant or not.
They all have UV inhibitors in them, and I've had some stuff outside in 
SoCal for going on 20 years now and it doesn't seem to have degraded much.


The brand I used in the past was Extren:
http://www.strongwell.com/

http://www.sdplastics.com/Extren20Brochure200804.pdf

there are other brands.