On 12/7/2010 7:43 AM, Jim Thomson wrote:
> Date: Mon, 06 Dec 2010 14:29:39 -0500
> From: "Roger (K8RI)"<K8RI-on-TowerTalk@tm.net>
> Subject: Re: [TowerTalk] Never-Seez and noalox?
> I'd not use any lube on tower joints, or any material that would reduce
> the gripping action of the leg overlap as that would reduce the over all
> tower strength and put more load on the bolts, which could lead to the
> elongation of the bolt holes.
> Also when use on bolt threads the torque required for a specific linear
> pull on the bolt is reduced substantially. In compression on a tower
> leg never-seez on the threads can lead a greatly increased crushing
> force on the tower legs. That needs to be taken into account when used
> on tower bolts.
> Roger (K8RI)
I think we said the same thing Jim except with different words. I use
Never-Seez on tower bolts and take that into consideration when
tightening them OTOH I never use it or Noalox on the overlapping joints
where the tower depends on the gripping action of one section on the next.
> ## There is nothing wrong with using never seize on tower leg bolts, done
> all the time.
> Portland bolt engs tell me that when bolts are lubricated, you need no where
> near the
> torque to get the same amount of tightness. Tightness and torque are 2 x
> different things!
> EG: a 3/8" g-5 bolt requires 38 ft lbs of torque when 'dry'..... but only
> 23 ft lbs when
> lubricated. Now if Joe ham lubricates the bolts [and mating nuts]... and
> uses 38 ft lbs of
> torque, you will have over tightened the bolt ! The engs also told me that
> to use those
> max torque figures they provide for the bigger bolts with caution..esp when
> UN lubricated.
> They tell me they break bolts all day long in the lab, when those UN
> lubricated max torque
> numbers are used. I lube all bolts [ and nuts] with lockite brand never
> seize. The marine grade
> brand offered by most 'never seize' makers is the best you can get. Made
> for fresh and salt water
> environments. [IE: rain for typ ham use].
> ## On both tower legs bolts like rohn 45-55 legs..and also typ al booms
> used for ants, there is no need
> to crank bolts super tight. You get em so tight, and after that, the
> tightness drops off... since you are then
> just crushing the tubing. On F-12 al booms, they use a combo of 3/16"
> solid AL rivets and 1/4" SS bolts
> [with SS nylocks]. I supplement the 1/4" SS bolts with another 8 x 3/16"
> solid AL rivets.
> ## I use never seize on all SS bolts and screws, when used outside..esp
> when SS nylocks used, other wise
> SS will gaul the threads.
> later... Jim VE7RF
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