[TowerTalk] Aluminum Tower Mast

[Jim Thomson]

Date: Wed, 5 May 2010 14:36:09 -0700
From: "knormoyle at surfnetusa.com" <knormoyle at surfnetusa.com>
Subject: Re: [TowerTalk] Aluminum Tower Mast




[Dennis] "From day one, we used an aluminum 2" OD THICK WALL ALUMINUM CONDUIT Mast."

I was curious about aluminum conduit. A quick search says that modern aluminum conduit is 6063 temper T-1
(our typical 6061 use is T6) 

Wikipedia says ( http://en.wikipedia.org/wiki/6063_aluminium_alloy )6063 T-1 has a yield strength of only 9kpsi

Regardless of the wall thickness, I would think the low yield strength would make many other options better for equivalent weight.

also, conduit is specified as I.D. was this 1.5" I.D. -> 1.9" O.D. conduit? or 2" I.D. -> 2.375" O.D. ?

??
-kevin

##  I just noticed the fellow mentioned he used al CONDUIT.   He didn't say what thickness.    We used  AL conduit
at work in yrs gone by, then it's all now steel, NO AL anywhere. [ think was mandated by building codes /electrical codes]
CONDUIT is SOFT material. It has to be, to bend the stuff.  Conduit would be 100%  useless  for a mast application.
  
T-1 /9 ksi is normal. I seriously doubt you could even  run either 6061-T6  or even 6063-T832  through any conduit bender,
even the hydraulic conduit benders.  It would snap off.    Somebody mentioned 7075 al alloy.   It's  good stuff
 too.. but VERY expensive... but it does have a higher yield strength than  6061-T6.     3003  is another flaky alloy...
ranging from K-1  to K-14  for hardness.  K-1 is only 6 ksi.   You can get 50'  rolls of AL tubing.   F-12 uses it for their
hair pin match's... it's like spaghetti. 

Jim   VE7RF