Doug, water pipe is ungraded steel and with usually poor seam welds, so
risky to use as a structural member. From the responses and IMO you
would be better off getting the scrap value for the pipe and building a
tower from 90 degree angles (square base) or easiest would be a tubular
tower with a derrick to hoist it.
Tube can be square and provides the restraint against the rotator torque
and usually comes in 20' lengths, sometimes longer. Square tube is A36
steel. Something like 3.5" square x 1/8 wall bottom with a 3" square
1/8" wall top would get you to 38' and probably needs a guy on the
bottom section, but that is my backyard engineering. A tribander and
VHF antenna would be the limit. A mast of the size above will weight
about 300# so a derrick is the best way to raise/lower it. Check out
the various catalogs for similar masts.
A BS in ME should be able to do the necessary calcs so why don't you
visit a nearby University and check with the ME department or give a
starving undergraduate Senior a few bucks. It's only a couple hours
worth of work or so for a mast design.
Grant KZ1W
From the
On 6/28/2015 8:39 AM, Patrick Greenlee wrote:
Galvanized water pipe is NOT very good as a strength member. If you
use it you will have to make allowances to get the overall tower
strength you need. Braces (lattice elements) will have to be closer
together than with other stronger material. This means you can not
safely copy a commercially made tower since your materials are not as
strong as theirs. You will need more and closer lattice elements.
It has been my experience when flattening the end of a galvanized
water pipe by hammering it on an anvil or using a 20 ton hydraulic
press that you can get it to crack or split. Heating it first and
flattening while hot works. There are DIY You Tube videos on making
your own forge out of a scrap car or truck brake drum
I wish you the best of luck with your project. I too have a very non
standard tower project in process. For a little info on that take a
look at QRZ.com NJ5G and scroll down to the pictures.
Again good luck with your project.
Patrick NJ5G
On 6/27/2015 11:45 AM, Douglas Ruz wrote:
Hello everybody !!!.
Thank you very much for all ideas !!!...it is amazing...i am learning
a lot.
Let me try give more information to all of you.
FIRST, Bryan, WA7PRC, you are absolutely RIGHT..."Reinvent the wheel"
is a trouble but i have not other choice...
Gerald, K5GW, yes i can get guy wires from electric power
company...so, guy wires are not a problem.
Jim Lux, sorry, i have not a lot of pipes and ground space, so, self
supporting is not possible. Guyed tower is my choice.
Rick, N6RK, yes, i am talking about 3/4 inch galvanized water pipe.
I am not the welder...I have been talking with the welder and he
knows it is dangerous welding galvanized parts but he work in OPEN
SPACE with a FAN to remove all gases.
He is also thinking use a CONTACT SOLDERING MACHINE and not a classic
ELECTRIC SOLDERING MACHINE...less gases.
To join sections i found that using a piece of 1 inch water pipe,
after "cleaning" the inside with a drill work perfect. Using bolts in
both sides to join each section.
I am WORRY about TWO THINGS:
TOWER STRENGHT: Is strong enought the 3/4 inch water pipe and 5/16
bars for braces to replicate a Rohn 25G ??
CORROSION: Heat during welding destroy galvanized protection...i can
not galvanized after welding...maybe some cold galvanizing is
possible...I am worry about corrosion...maybe painting inmediately
after soldering minimize corrosion.
I am listening (READING).
Thanks,
73...Doug, CO8DM
"No creo que haya alguna emoción más intensa para un inventor que ver
alguna de sus creaciones funcionando. Esa emoción hace que uno se
olvide de comer, de dormir, de todo." - Nikola Tesla
----- Original Message -----
From: Bryan Swadener
To: co8dm@frcuba.co.cu
Sent: Saturday, June 27, 2015 2:14 AM
Subject: Re: [TowerTalk] Homebrew tower...
Hi Douglas,
IMO, it's too much trouble to "reinvent the wheel". You need to be
not only the fabricator but also, structural engineer. Then, after
you've designed and fabricated the parts, you'll want to hot-dip
galvanize the parts so they'll last a long time. Just save your
money to buy what you want. I did exactly that.
vy 73 es gl,
Bryan WA7PRC
http://www.tinyurl.com/wa7prc-tower
Date: Fri, 26 Jun 2015 11:50:40 -0400
From: "Douglas Ruz" <co8dm@frcuba.co.cu>
To: <towertalk@contesting.com>
Subject: [TowerTalk] Homebrew tower...
Hello,
I would like a tower in my property but i can not buy a Rohn or
any other tower, so, I WILL BUILD ONE...or will try build one.
I have many galvanized tubes, 7 ft long, 1 1/32 inch diameter
and 1/8 inch wall.
I have been reading dimensions of Rohn 25G and 45G...i like 25G.
My goals are:
-Reach about 50 ft high.
-Install a rotator.
-Install a lightweight tribander yagi (maybe an spiderbeam), a
6m yagi (5 elem) and maybe 2 elem moxon for 40m...I know 50ft is not
OK for a 40m antenna but my anchor points are to close, so, i can not
install a higher tower.
I have another important questions...it is about GUY
LINES...what is the cheapest guy line solution ???
73....Douglas, CO8DM
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