On 12/7/2011 8:29 AM, Jim Thomson wrote:
> Message: 5
> Date: Tue, 06 Dec 2011 21:44:17 -0500
> From: K8RI<K8RI-on-TowerTalk@tm.net>
> Subject: Re: [TowerTalk] Tower Leg Maintenance
>
> On 12/6/2011 4:39 PM, Frederick Vobbe wrote:
> ## U could also,[ if the tower is all in sections], stuff the TV
> camera into each leg, like the plumbers all do, and see the inside of
> the legs... in colour. Dunno how small an ID those things will fit
> into though.
Better yet is a "Bore Scope". It's a tiny TV camera on a flexible shaft.
They are used to look at the inside of aircraft engines, pipes, and
other inaccessible places.
> IF it's not that bad inside, you might be able to hit it with a pressure
> washer,
> or fabricate something that will fit inside each leg...and fit onto a
> pressure washer. IF you use
> the rotating brush, you may just tear off zinc left and right,
If the Zinc coating is that fragile I'd worry about rust underneath it.
Normally a wire brush just makes it shine.
> and make things worse in the process.
> Then pour in a ton of cold galvanizing from a 1 gal container. If you
> capped off the bottom legs
> 1st, then poured it in the top legs, then capped off the top legs, then
> balanced it on a single
> saw horse, you could pivot it like a teeter-totter..and get it fully coated
> really good. Then
> roll the tower onto another face, then repeat.
I've used that method to coat the inside of DOM masting.
>
> Then open off the 3 x caps on the bottom, one at a time, and let any excess
> drain into a container.
> Now I can see why solid legs are popular. Pi-rod uses em.
> Trylon also makes a 10' tower section,
> http://www.trylon.com/lightdutytowers/stgtowers.asp
> 18" wide, but 129 lbs per section, solid legs, and stronger than 65G. 7/8"
> solid legs..and 1/2"
> solid bracing. Not cheap though. I have never seen one. The way the
> connections bolt together
> looks slick though. A single 5/8" A-325 bolt [6" long] for each leg, via a
> welded spigot. Just
> 2 x hollow tubes welded to the tower legs, one at the bottom of the upper
> section....and the 2nd one
> is at the top of the lower section. 6" bolt just drops in. The solid legs
> butt against each other. I have seen
> that exact splicing technique years ago, at one of our telco sites, on a 26"
> wide tower. It makes
> for a fast assy.
ROHN 45G and up are listed as available with solid legs.
73
Roger (K8RI)
>
> I have also see towers, like rohm 65G, where square plates are welded to the
> bottom of each leg, and
> 4 x bolts join the 2 x plates. A drain hole is on each leg, facing the
> inside of the tower. Seen these things
> get plugged up, fill with water, then split wide open when it freezes, what a
> mess.... with a 16" rip right
> up the leg. The tower engs finally said screw it, and went to solid
> legs...or angle legs. Angle leg towers
> were either 60/90 deg..and of course either 3 or 4 sided. On 4 x sided
> towers, 8 x guy wires were used per level,
> 2 x per face. They don't budge, and no star [TQ] bracket required. Some of
> these installs are on mtn tops,
> or way out in the bush, or on small islands etc. They only get inspected 1-2
> per year, wx permitting. That
> orange/white paint only last so long too.
>
> later.... Jim VE7RF
>
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