[TowerTalk] fiberglass insulators for yagis

[Jim Thomson]

Date: Fri, 20 Jan 2017 11:33:06 -0500
From: "Joe K2UF" <joe at k2uf.com>
To: "'Jim Thomson'" <jim.thom at telus.net>, <towertalk at contesting.com>
Subject: Re: [TowerTalk] fiberglass insulators for yagis

Hi Jim,

I Have used Max Gain for several years for fiberglass supplies.  Their web
site is 'mgs4u.com'.  They have a good selection of fiberglass etc.

Good luck,

73 Joe K2UF

##  max gain systems  has solid fiberglass insulators....all the way up to a 
max of  1.5 inchs  in diam.  Mcmaster carr only has em up to a max of 1.25 inchs. 

##  max gain systems  offers them in 2-4-8 ft lengths and also 6 inch lengths.   They
will also cut them to any length you want.   Depending on diameter, they also come
in off white... or black.   Its the 1.5 inch diam solid rod that I require. 

##  as far as the solid fiberglass vs  solid Aluminum... 6061-T6,  I have decided to use
solid 6061-T6.   Since the oem insulators are no longer required, the oem 3 inchs of 
exposed  insulator is also not required.    So the new, solid one inch AL  rods will be used as
an inner linear / splice joint.   IE: the oem al tubing on either side of the oem 1 inch
solid fiberglass rod  was  1.25 inch OD  x .083 wall  aluminum tubing...which  was swedged
to fit the 1”  solid fiberglass.   I will simply butt the 2 x pieces  of 1.25 inch OD material together, 
with the new  1 inch solid Al rod inside as the splice joint.  Losing  3 inches on either side is a non issue,
since the overall length in the re-design is going to be reduced anyway.   Then no need to install a 
jumper across any insulator.   Just a single  1/4 – 20 SS bolt  on either side.  

##  BTW, tensile strength is stretching material.  EHS steel cable is good for tensile  strength, but obviously 
lousy for compressive strength.   Yield strength is when   you bend it... till the point where it almost breaks. 
But yield and flex are 2 x different things.   Fiberglas fishing rods wont break, but they will flex like crazy, but they
are also very long vs an insulator, and designed differently.  Wood has loads of compressive strength, but lousy
tensile strength.    

Jim   VE7RF