[TowerTalk] Inspecting tower sections

[Mark L.]

Hi David;

I'll try to address each or your questions below...

<< If the end of a top section is bent a little where many of us have 
allowed one leg to stay in the tube below as we tilt the section during 
removal is that bend likely to be significant to structural integrity? >>

I would say that the structural integrity is compromised only if the leg 
section has become kinked or distorted out-of-round. The steel in the legs 
is ductile enough to let you correct minor bends without damaging the 
tubular shape.
The biggest problem I can see here is that you'll have a heckuva time 
assembling sections involving a leg that is bent more than about a half an 
inch or so out of alignment.
Steve at Champion Radio sells a good gadget for this called a Leg Aligner, 
which allows you to hook on to both ends of the mating leg sections and 
lever them into alignment.


<< What is a best way to straighten a bent leg and maintain structural
integrity? >>

Although I have never had to do this, I would insert a close-fitting pipe 
over the bent leg end and gently bend it back into alignment. Align the end 
of the pipe with the bent area to apply the corrective bend to the area that 
needs it. If it returns to its original shape and alignment with no trace of 
buckling, kinking, or other noticeable distortion (usually the case with 
small bends), I would have every confidence in it's original integrity. 
However, once a piece of metal has been bent many times, it can become 
weakened. If you see a leg that looks like it has been bent back to shape, 
but still has some residual curves (roller coaster shape), pass it over for 
purchase.

<< Is it wise to spray some cold galvanize on any section that has been bent 
and straightened in case there are unseen hairline cracks in the galvanize? 
 >>

The tin is very ductile and should flow with minor bend correction. I would 
guess that if a bend is severe enough to crack or flake the galvanizing, the 
leg is a goner per above distortion criteria. I don't have enough experience 
here since I have never seen this. Perhaps other, more experienced hams 
could pitch in here with a comment. The cold galv. definitely won't hurt.

<< 5) Cracks or multiple pinholes in the welds (inspect every weld).

Is a magnifying glass recommended or should these be obvious without
magnification? >>

Good question. Poor welds that I have seen have many pinholes like a sponge 
that are easily visible to the naked eye, about the size of a ball-point pen 
tip.


<< Thanks again! & 73, DavidC  K1YP >>

Glad to help! Long Live TowerTalk!

--...MARK_N1LO...--


______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

--
FAQ on WWW:               http://www.contesting.com/towertalkfaq.html
Submissions:              towertalk@contesting.com
Administrative requests:  towertalk-REQUEST@contesting.com
Problems:                 owner-towertalk@contesting.com
Search:                   http://www.contesting.com/km9p/search.htm