[TowerTalk] F12 C19XR Rivets

[Patrick Greenlee]

As someone who has installed thousands of "pop" rivets both with manual 
and pneumatic guns I can attest to the efficacy of putting all or most 
rivets in their holes before popping them or distortion may interfere 
with putting them in later necessitating a little reaming to fit them in 
and that little reaming is a bad thing. Another approach that is useful 
when able and applicable is to not drill all the rivet holes before 
installing any rivets.  Install enough rivets to hold the parts in 
proper relationship and then drill the rest of the holes and put in the 
rest of the rivets.Do not oversize the drill bit.  For 1/8 inch rivets 
9/64 is the largest "good" sized hole.

Patrick         NJ5G


On 3/9/2016 10:59 PM, Roger (K8RI) on TT wrote:
> It would certainly seem like it, but I'm not so sure.  Most of the 
> better antennas work well once tuned up and may work great for some 
> years.  The C3i antennas were great performers for some years. Yet 
> when taken down, the coax match on all had the solder dissolved to the 
> point where the matching section was no longer connected. They would 
> have stayed up for 4 or 5 more years before they failed, but a flock 
> of Cormorants decided "THAT C3i 7L 6-meter antenna" was going to be 
> their roost.  So I think failures are often attributed to the weather 
> or age rather than design.
>
> I found a broken element tight at the first rivet on the C19XR. 
> Admittedly it was from rough handling.  My wife had some neighbors 
> move the antenna (on saw horses) when I wasn't available to help. 
> Holes in elements weaken them at that point, so I'd want that first 
> rivet a little farther back so the larger tube would support the 
> smaller at the weakest point.
>
> Loose rivets?  I wonder if that was an installation problem?  With pop 
> rivets even cleaning the hole out with even a 1/64th over size drill 
> would likely be a source for problems. Pop rivets should be snug.  If 
> installed one-at-a-time the following rivets may not want to go in, 
> resulting in a hole being redrilled
>
> 73
>
> Roger (K8RI)
>
>
>
> On 3/9/2016 Wednesday 8:21 PM, Kelly Taylor wrote:
>> Isn’t a lot of this talk a bit of picking the pepper?
>>
>> If joint conductivity of aluminum elements was a serious issue, 
>> wouldn’t we have heard something about it in the, what, 60 years 
>> we’ve been using aluminum tubing for antenna elements?
>>
>>
>> 73, kelly, ve4xt
>>
>>
>>> On Mar 9, 2016, at 6:36 PM, George Dubovsky <n4ua.va at gmail.com> wrote:
>>>
>>> If you weld the aluminum tubing, you destroy the heat treatment in 
>>> the Heat
>>> Affected Zone, resulting in a much weaker element.
>>>
>>> 73,
>>>
>>> geo - n4ua
>>>
>>> On Wed, Mar 9, 2016 at 6:43 PM, Tom_N2SR via TowerTalk <
>>> towertalk at contesting.com> wrote:
>>>
>>>> If you weld the tubing together, what is the wind rating then?  
>>>> Kind of
>>>> difficult to get apart, but very little risk of losing electrical 
>>>> contact,
>>>> rivets failing, rusted screws, etc.
>>>>
>>>> Someone should try it and report their results.
>>>>
>>>> Tom, N2SR
>>>> _______________________________________________
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>
>