[TowerTalk] anti-seize

[K8RI on TowerTalk]

>I use anti-seize on all my tower/antenna stainless hardware when 
>assembling.
> I will be using grade 8 bolts in the mast clamp on my Prosistel. Should I
> use anti-seize on all bolts as a general procedure and not just stainless?

Anti seize compounds have good and bad points. They do what's advertized and 
you can get SS apart a year or two after putting them together, BUT when 
used on tower bolts that are torqued the normal values are given for *dry* 
threads.  An anti seize compound that also lubricates and I know of none 
that don't, will put considerably more clamping force on tower legs and mast 
clamps for a given torque reading than for the same bolts dry. This can 
easily be enough pressure to deform tower legs.   Depending on the size of 
the bolt and the thread pitch the pressure can be multiples of the design 
pressure.  Due to the nature of the mast clamps I'd not be very concerned 
about the clamping pressure of those and would put anti-seize compound on 
them.

What's needed is a measure of the crush, or clamping pressure for the bolt 
dry and again with the anti-seize compound. Then the torque could be 
adjusted to give the design clamping pressure.

I don't know of anything in the tower assembly that requires grade 8 and 
grade 5 should be fine. OTOH Grade 8 shouldn't hurt any thing except they 
cost a little more.

OTOH if you really want some good bolts I just received two boxes of 
aviation bolts with rolled threads.  They are a tad more than the grade 8, 
but I think I might have a few of the right sizes <:-))   The larger sizes 
are engine mount attach bolts.

73

Roger Halstead (K8RI and ARRL 40 year Life Member)
N833R - World's oldest Debonair CD-2
www.rogerhalstead.com
> Tnx
> N2TK, Tony
>
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