The format of this and several other reflectors is excellent for bringing
knowledge to the surface. I have gained valuable knowledge more times than
I can count, via this process. I think it works like this:
Someone asks a question (we have proven that there are no stupid
questions!) The question makes sombody else realize that they know (and
almost forgot about it, because they have retained the knowledge for so
long) things that can help the person making the query. The knowledge or
experience gets exposed and usually many other subscribers are helped.
I was within a few seconds of sending a bunch of e-mail to the dumper, when
I realized that I had some experience that some others didn't have, and
might offer something useful to someone.
I want to ask all of the towertalk subscribers to be careful when weeding
through the pile of stuff to be very careful with the delete button. At
least try to read and understand what has been said or asked. You probably
have a gem hiding in the back of your experience that will help us all. I'm
not ashamed to admit that this request is purely selfish!
To all that are interested in the anti-seize topic,
Read on, others should hit the delete button NOW!
Thanks to all who found the previous post of value. I am shocked at the
response! Thought I was going to bore everyone to tears.
Many of the responses request more information. Instead of singularly
answering each one, we'll try to address them all at once.
The bulk of the requests for more information involve the "How to, and What
to use, Where to get it" stuff.
I've never believed in giving anyone the quick and dirty "How to" answer,
without trying to inform them of the principles behind the simple answer.
The behind the scenes knowledge allows everyone to think and advance the
"state of the art" on their own!
The Principles,
behind seizing prevention are not very different from those of applying
"GOO" to your antenna electrical connections. The subject of a previous
post, 4/26/98.
Both types of "joint compound" have a liquid vehicle to carry some kind of
solid particles into the connection. Regardless of the application
(electrical or mechanical) the purpose of the liquid vehicle is to readily
allow the application to spread and deposit the suspended solid particles
to all mating surfaces. Once, this has been accomplished, the job is really
done by the solids.
The materials were designed this way, and our experience verifies it! Any
of us, who have applied some kind of "Goo" to a connection have observed
that after some amount of time, the compound dries up and all that is left
in the connection is the solid material.
This is caused by a natural leaching process, whereby the repeated
depositing and flushing activity of moisture in the connection washes the
liquid vehicle out of the connection. We also observe that some of the
solids are also washed out, but fortunately, some of them are left in the
connection to do their job.
In the anti-seizing application, the solids are almost always softer than
the parent materials (parent materials refers to the material on either
side of the connection, like 300 series stainless in the nut & bolt of a
connection, or forged steel on each side of a good turnbuckle.) They are
also trapped in between the mating thread interfaces mechanically by the
pressure created by tightening the fasteners. When we come along years
later to undo the connections, the trapped soft particles get chewed up and
destroyed, preventing the parent materials from comming into contact with
each other and gaulling. As stated in the previous post, identical parent
materials will want to gaul, or deform equally together to distort each
other, causing a mechanical lock. Sometimes, an effective anti-seizing
solid may be harder than the parent materials. In this case, the joint will
come apart, but damage will be done to the parent materials requiring
replacement. The key for the anti-seize solid to be effective is for it to
have a different hardness than the mating surfaces. The softer solid is
preferred as it allows the mating parts to be reused.
The galvanic corrosion problems with certain solids are addressed in the
previous post mentioned above.
Ok, enough about the boring, "Why" stuff. Let's get to the "What to use"
"Where to get it" stuff!
This should be the easy, direct, "idiot proof" answer, right?
Sorry, it is the most difficult one! The selection of an anti-seizing
compound is directly connected to the environment your hardware will be
exposed to. If the connection is going to be flooded with repeated moisture
on a daily basis, you need to use a compound that will not completely exit
the connection. If your environment is relatively dry (moisture condensing
on the hardware 1/3 of the year) you can use almost anything.
I have extensive, job related, experience with several compounds and
personal Ham related experience (got to remember the fun side of life!)
with others. These will be passed on as empirical knowledge (some may wish
to categorize them as anecdotal, No Comment Required, It will go
immediately to the dumper!).
There is a product called "LeadPlate" that I have used in a variety of
applications. Several of the applications have been high temperature
aerospace. The really neat aspect of this type of product is the extremely
soft nature of the lead solids. They seem to very easily deform and stick
to the mating surfaces. When the vehicle goes away, the lead particles are
still stuck to the mating surfaces, by virtue of soft maleable nature of
the lead, so that the connections always came apart.
I had a small tower, 7 miles from the ocean, in So. Calif. that I used
Permatex (Tm) anti-seize on all threaded connections. This compound is very
clearly silver in color. I do not know what the solids are. My guess is
that they are zinc. Nevertheless, this installation came apart easily after
10 years, when I moved to the new QTH in Nevada.
Then, my experience on the job, sending myself and a host of others to all
points of the planet, to un-fetch hardware on the sailing yachts.... says
that if one doesn't want to encounter significant grief, one selects the
really good stuff. The empirical history on this experience has proven that
all common anti-seize compounds behave well initially. When they are
exposed to daily washings of condensation, as is experienced by anything on
the ocean, All of the good stuff goes away, and the poor guy trying to take
the hardware apart ends up spending 80% of his time getting it apart, 10%
of his time getting the local machine shop to make new parts, and 10% of
his time putting it all back together.
So, what is the good stuff? Its name is Tef-Gel. This is the toughest
material I have ever seen. It is Teflon based and is not cheap. Both the
vehicle and the solid seem to stay in the connection! I have now gone to
service several yachts annually, that previously had any of the other
anti-seize compounds, and were an annual nightmare. Since, converting them
to a Tef-Gel lubricant, the annual service has become more of an
interesting holiday, than the previous nightmare. This product is still
there, to do its job, where all of the others were washed away. Reminder,
this discussion is aimed at preventing things that must move from getting
locked up!
This product is sold in the marine distribution chain. I would suggest that
you look for general marine retail outlets. In the U.S. there is a company
called "Port Supply" that has several retail outlets along both the western
and eastern coasts.
Time to get back to some of the simple stainless connections on amateur
antennas and towers that we don't need to move, but need to stay put. In
the marine industry, we evaluate which connections are likely to be
serviced regularly, and those that will require annual service. The
regularly servicable connections that have potential gaulling materials,
and are likely to vibrate loose to land on someones head, are simply
assembled with "Blue" Loctite (Tm). The fascinating thing about these
connections is that, the "threadlocking" Blue Loctite provides enough
lubrication to the connection to prevent gaulling. The compound cures
properly, when the parts are not contaminated with oils, it seals the
connection off from moisture, and its eventual corrosion, and is easily
disassembled later. The locking feature of the compound is essential, as
the anti-seizing compounds cannot provide a lock. They are designed to
prevent a lock. Gets confusing, Eh?
If you are putting semi-permanent stainless fasteners together, use the
"Blue" threadlocking Loctite. Critical connections, that make masts fall
down and kill people, get the "Red" or "Green" Loctite. Things that require
regular service and lubrication get the Tef-Gel (like noisy tubular
towers).
Hope I answered all of the questions! Probably didn't, so feel free to send
more!
73, Kurt
YagiStress - The Ultimate Mechanical Design Software for Yagi's
Visit - http://freeyellow.com/members3/yagistress
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