[TowerTalk] re: weatherproof boxes

[W0UN -- John Brosnahan]

>I've had my Omega Match capacitors for my shunt-fed tower in a Rubbermaid 
>container for about fifteen years now, at two different locations.  As far 
>as I can tell, the container is like new, except for the entry and exit 
>holes I punched in it when I first installed it.  Mine sits upright on the 
>ground, with a cinder block in it to keep it from walking around in a 
>breeze.  The lid quickly collects water in its depressions on top, but 
>nary a drop gets inside.


I am certainly a big fan of CHEAP.  Around 1980 I needed some
covers for phase shift networks and decided that outside-rated
plastic trash cans might be the answer.   And knowing that BLACK
was probably the best for UV I decided to call Rubbermaid and
find out how the rated their trash cans.  I think the guy I talked to
was surprised that someone would actually call about testing
methodology and ratings and he seemed very willing to chat.
It has been a long time so I don't recall the details but they used
a controlled environment with UV light sources and specified the
units with something like 10 years outdoor exposure.   So I bought
a number of them and used them on a project going to a French
customer.   He was a university professor and was pleased that
I was trying to keep costs low--AFTER his initial reaction of having
his phase shifters pre-installed in trash cans.

Well they only lasted a couple of years--so I was pretty disappointed
with the results and haven't used them since.  But maybe they
are built with a better plastic now and are more UV resistant.

But the real secret (I believe) is to protect whatever you use from
the worst of the UV radiation.  And paint does a pretty darn good
job.  It turns out that Krylon spray paint now has a line that is
designed to ALSO cover PLASTIC (in addition to the usual metal and
wood).  I actually prefer Krylon paints over Rust-oleum paint because
it is INCREDIBLY more resistant to runs and drips.  But I have not
had any plastic parts in the sunlight long enough to see just how well
the black Krylon really does.  In any case I think I would try to give
any plastic box as much help as I could with UV resistance by using
an appropriate paint.

Now here is a little reward for those who actually read this far
on this note.  It is about galvanizing paint.  I have normally used
the Rust-oleum galvanizing paint on a lot of things and it works
pretty well at protecting steel parts.  Recently at Lowes I noticed
a Rust-oleum PROFESSIONAL Galvanizing Compound and
decided to try that.  It seems to work well and it has a texture
and a finish that I really like.  Looks almost like an aluminum
casting.   Besides the Zinc dust it also has non-leaf aluminum
paste (whatever that is).

And the real kicker is that this comes in 20 oz cans (the regular
stuff is only 16 oz) and the 20 oz cans of the PROFESSIONAL
stuff (whatever that means) is 10 cents CHEAPER than the
16 oz cans.  The can is printed "Cold Galvanizing Compound"
but there is a stick-on paper label that says "Bright Galvanizing
Compound".   I guess if you want things to gray out and merge
with the haze then maybe the regular stuff may be better  -- but if
you want something that looks NICE then this stuff has a very nice
texture and finish.  I have not had any outside long enough to
be able to compare durability between the two Rust-oleum
products.  But if I want something that is protected by "Superior
Corrosion Resistance"  (their words) and that looks very nice
then this appears to be the stuff to use.

--John   W0UN

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