Roger,
I have one of those towers to put up one day too. I was thinking rather than
weld the ears to the large rod as the factory shows, using threaded rods
coming out of the concrete and using a 1/2 inch plate to bolt the rods to.
Then welding the ears on the plate that then bolt to the tower.
That way I could easily use the foundation for a different tower if I wanted
to change to something else.
The threaded rods also make for easy leveling of the tower.
What is your opinion of that?
Thanks
Gary K4FMX
> -----Original Message-----
> From: TowerTalk [mailto:towertalk-bounces@contesting.com] On Behalf Of
> Roger (K8RI) on TT
> Sent: Sunday, April 13, 2014 2:46 AM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] Welding Rebar
>
> On 4/13/2014 1:47 AM, Brian Amos wrote:
> > If you weld it the rod may rust which will cause the concrete to
> burst.
>
> Rusting requires an oxidation source. Rod protruding from the concrete,
> or flux. I'm using Metal, Inert Gas or MIG for short. I'd not want to
> use stick welding. These are "tack welds, not true welds. They are just
> enough with what wiring I can do with one hand, that I'm not worried
> about the cage changing shape before we pour the concrete. The "twist"
> is much like we use on aircraft nuts and bolts, except we are using soft
> iron and not #20 or 24 SS.
> I'm used to sticking the two ends into a tool, pulling a handle that
> reminds me of a Ty-Wrap tool. Just about instant twist.
>
> The Iron wire is large enough , #14 I think, that it can be twisted with
> regular pliers.
>
> Tack welds are small enough that I'm not worried about changes in
> strength.
>
> There are 3 major welds. Those are ones holding the 1/2" X 3" X 25" ears
> to the #10 rerod The tower and raising fixture bolted directly to
> these.
>
> If we could get the rerod to stay in place we wouldn't need to fasten
> it. The rod just serves as a reinforcement for the concrete, although
> with the LM470 the big stuff that holds the tower is part of the cage.
>
> I like the idea of everything connected as it serves as a very good UFER
> ground. Course that connects to a network of over 600 feet of bare #2
> that is cad welded to 32 or 33 8' ground rods.
>
> Speaking of grounds. I've lost 2 of the big Diamond dual band (144/440)
> antennas. I think I've lost a system ground in the shop and it went to
> ground through the antenna.
>
> 73
>
> Roger (K8RI)
>
>
> > Not
> > a fun situation as usually the recommended repair is completely remove
> the
> > foundation and replace it. As a foundation engineer I only hear the
> > failures and what the standard of practice and code say, so maybe it
> has
> > worked under the right circumstances. If it has an issue and it was
> not
> > built to code the insurance company will not cover you.
> >
> > Tying rebar is not fun and can be hard work but stout teenage boys
> will
> > learn quickly and work for a small portion of what a concrete company
> would
> > charge. I usually offer a favorite meal ajdand tgat is ebough. You
> may
> > even find some free and experienced help from your ham club. I know
> > whenever someone in my club needs help with something that falls
> within my
> > line of work I am more than willing to lend a hand.
> >
> > Brian
> > KF7OVD
> > On Apr 12, 2014 10:42 PM, "Edwin Karl" <edk0kl@centurytel.net> wrote:
> >
> >> Roger,
> >>
> >> As part of my mis-spent youth I was an iron worker, worked at it for
> about
> >> 6 years.
> >> We were referred to as "rod busters" by some. In any event installed
> lots
> >> of iron
> >> in the new York area.
> >>
> >> Now that I'm retired, I built my own home, not with my hands, but was
> the
> >> general
> >> contractor. You can do that in the country ... I did do the
> reinforcing
> >> myself; so my
> >> driveway, sidewalks, patio, basement walls and floor all have steel
> >> internally. The
> >> also barn has a reinforced concrete floor.
> >>
> >> The tower is an AN Wireless 90 footer with a big foundation, rear 3
> >> layers, top bottom
> >> and middle is about 12 feet deep, took 21 yards of concrete to fill
> the
> >> hole. There is a
> >> section of tower made to go in the foundation which splices to the
> rear.
> >>
> >> Now I'm saying all this because of a decision I made years ago, if I
> had
> >> the chance, this is
> >> how I would choose to build my own home, etc. It might be nit picking
> but
> >> the issue with me
> >> probably pertains more to structural iron, like the tower etc. Don't
> do
> >> anything like welding
> >> which may change the characteristics of the iron negatively. Also
> affects
> >> galvanizing etc.
> >> Probably way over thinking the issue, which I usually do.
> >>
> >> I also will confess in my day, except where cad welding 1 1/4 rear
> for
> >> power houses etc,
> >> never saw rear welded. Generally a splice is 20 times the diameter
> side by
> >> side and double
> >> tied.Compared to structural, rear is soft, we would bend it on site
> for
> >> hooks and angles, so I
> >> suspect it's already not too stuff. But as I said initially the bar
> >> reinforces the concrete, which
> >> holds the bar in place.
> >>
> >> Sorry for being so lengthy ... but, if there are other issues as you
> >> mention than explain why welding
> >> might be acceptable. We would take columns and beams using wire to
> kind of
> >> guy it internally, if
> >> the item has a long way to go or was a difficult pick for the crane
> etc.
> >> If you are having the job
> >> fabricated off site it probably could be done either way, if you're
> alone
> >> tack welding could work.
> >>
> >> I wish you well, and would appreciate hearing from you as the project
> >> progresses.
> >>
> >> By the way, 8 or 9 inch lineman's pliers and end cutting nippers are
> tools
> >> of the trade, The nippers
> >> work real well when tightening the connection, After a few mistakes,
> you
> >> can get the hang of it.
> >>
> >> Very 73!
> >>
> >> ed K0KL
> >>
> >>
> >>
> >> On 4/12/2014 9:37 PM, Roger (K8RI) on TT wrote:
> >>
> >>> On 1/5/2014 12:58 AM, Roger (K8RI) on TT wrote:
> >>>
> >>>> On 1/4/2014 4:01 PM, Ed K0KL wrote:
> >>>>
> >>>>> I can't stand it any longer ...
> >>>>>
> >>> And the problem is?
> >>>
> >>> If wired in place or near the hole they work fine. If shipped, or
> handled
> >>> a lot they seem to come already welded.
> >>>
> >>> As I only have one useful hand, tack welding is faster, easier, and
> makes
> >>> for a far more secure joint than wiring one with just one hand.
> >>>
> >>> I noted when at my steel supplier, they had a cage, mostly done that
> was
> >>> all welded. The customer would put it on a trailer, haul it 10
> miles or so
> >>> and then stick it in the hole with the same dimensions as when he
> picked it
> >>> up.
> >>>
> >>> 73
> >>>
> >>> Roger (K8RI)
> >>>
> >>>
> >>>
> >>>>> Wire ties are fine to keep the rebar touching from bar to band
> (the
> >>>>> smaller rod surrounding the
> >>>>> verticals or horizontals as it were). It has been used for years
> on
> >>>>> buildings, roadways, etc. Generally
> >>>>> speaking the concrete holds the connection together, the
> connection and
> >>>>> rod make the concrete
> >>>>> strong ...
> >>>>>
> >>>>>
> >>>> Order towers with the rebar cage and they likely will come welded
> and
> >>>> not tied.
> >>>> That's been the local experience.
> >>>>
> >>>> 73
> >>>>
> >>>> Roger (K8RI)
> >>>>
> >>>
> >>> _______________________________________________
> >>>
> >>>
> >>>
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