[TowerTalk] Masts
J. Kincade
w5kp@swbell.net
Fri, 08 Jun 2001 12:15:58 -0500
Mark, I cc'd your reply to the list for info. Local supplier here (they have
the special tubing market cornered in the Oklahoma City area) says they are
willing to have their supplier divert my tubing to a galvanizer in Tulsa and
have it hot dipped enroute to them, for a fee. No galvanizers here with a
tank long enough. Don't know what that fee is yet, but I'm pretty sure it
would total up to less than $528! I have asked them to track down and quote
3/16" and 1/4" 4130, and also 1026 or 1027. They have already quoted 4130
1/4" at $6.75 per foot + shipping and galvanizing, which is fine with me
(depending on the galvanizing cost), but they are still trying to find out
if they can get a specified length (24') rather than taking whatever they
get sent between 17' and 24'.
I agree with you that I should probably go with the 1/4" wall, but
unfortunately that limits me to 17' if I use the Texas Tower stock stuff,
and I'd sure like to have that extra 7 feet, not to stick anything higher in
the air (I'd just add a tower section for that), but to give me 12' inside
the tower and 12' outside, instead of 5' and 12', which I'd guess would be a
bit more stressful on the rotator (Yaesu 1000).
73, Jerry W5KP
----- Original Message -----
From: <KI7WX@aol.com>
To: <w5kp@swbell.net>
Sent: Friday, June 08, 2001 11:23 AM
Subject: Re: [TowerTalk] Masts
> Steel tube really can be tough to find. Here's what I did:
>
> TW Metals is a large metals yard that stocks virtually every type of tube
and plate that one could want (titanium, steel, aluminum, etc). I may have
the number wrong, but a single stick of 1025/1026 steel tube 2" OD x 0.25"
wall would be about $7 a foot shipped. This is a wholesale yard so as you
buy more the price drops considerably. They also have 4130 material but I
didn't ask for a price as I didn't need the extra yield strength. I also
went to 3/8" wall from 0.25" wall because the price difference was minimal
and I figured it couldn't hurt to be thicker. It was heavy though.
>
> I purchased 3 pieces of steel tube - 24' x 2" x 3/8" wall and the cost was
right around $120 each (about $2 per foot cheaper than buying one piece at a
time). I later sold the remaining two lenghts to other club members at my
cost. They were happy to get them.
>
> The only problem with this approach is that the tube comes without any
rust protection. I cold galvanized mine, but have not been particularly
happy with the results. Any nick on the tube and rust will form rapidly
once it is in the air. At 100 feet up and 15 feet sticking out of the tower
it's not easy to recoat the tube!! If I had to do this again I would start
with a stronger, epoxy type finish like POR 15 http://www.por15.com/ or
even better, find some way to get the tube galvanized from the start.
>
> I'm sure you know that K5RC sells steel tubing as mast material. Tom's
masts are 4130 material in 3/8" wall and he can get the tube galvanized for
you. http://www.consultpr.com/2inchmast.htm Price according to his web page
is $22 a foot galvanized. That's $528 for a 24 foot length which is steep,
but it's a fine mast and you won't have to worry about it.
>
> Depending on where you live I would consider the following: If you can
find a local galvanizer then order up several lengths of 24 foot tube in
whatever wall thickness you want from a place like TW Metals and then have
them galvanized. If there are other hams in the area get some folks to go
in with you and the costs will go down for everyone. If this is a one time
event I would just spend the extra cash and just get the long galvanized
tube from Tom and know that you have a very strong tube in the air, or go
with the shorter tube from TexasTowers. I would think you'd want at least 10
feet between your 40M beam and the C3XLD. The C3XLD is a pretty big antenna
as I recall, so using the .120 or .180 wall stuff probably isn't going to
work. You'd have to do the calculations. If you ever end up with a bent
mast it'll cost you a lot more than the difference between the TT mast and
the K5RC mast to get the bent one out and replace it. Bent masts are a
serious pain in the butt !
> to deal with.
>
> If someone has a better idea / source of masting material please pass it
along.
>
> Final thought: don't underestimate the difficulty of moving around a 24
foot long piece of steel tubing. It's long and heavy. If you have to
transport it around you'll need a truck with a good rack, or some sort of
trailer.
>
> Cheers,
>
> Mark
> KI7WX
>
>
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