[TowerTalk] Expanding Foam

Roger L. Elowitz K2JAS@worldnet.att.net
Wed, 19 Nov 1997 12:07:08 -0500


Hi Gang,

I am reading all the posts about expanding foam that fills all the air
gaps in the hole you make in the side of your home to bring in coax and
control lines. The expanding foam spray has one serious drawback... the
next time you go to add or remove a cable... you have a mess of
crumbling foam on your hands.

I believe I've solved the problem with my 3-inch hole for cabling... by
stuffing the hole with newspapers.  This lasted quite a while.  After
all, we only want to limit the ingress of air and insects. The next
time I added a cable I got an even better idea. I had several pieces of
foam rubber packing material laying around... the stuff that lines
camera cases or is used for shipping computer hard drives. I stuffed
the hole with this stuff and it is simply "wonderful."  It's easily
removed, no mess, and easily replaced.  No big deal. You can also buy
foam weatherstripping to do the same job.

All the cables that enter this hole have a semi-circular "drip loop"
whereby they must rise since they approach the hole from below. This
keeps water from running down the cables into the foam. Little "drip
strings" can be added to the bottom of each cable to drain water...
although I haven't found this necessary.

Lastly, to keep water out of the hole I place a sheet of white aluminum
siding in the bottom lip of the siding just above the hole and let it
hang there covering the hole and the coax coming in from the sides. You
can easily substitute aluminum roofing flashing obtained in Home Depot.

With this method... I don't worry about messy caulking the hole,
crumbling hardened expandable foam, insects and water or air ingress.
The hole, which is made large enough to remove cables with 8-pin Cinch
Jones connectors on my rotor control box wiring... can easily be
accessed for any new cabling.  So simple.  Now all I have to start
thinking about is a lightning bulkhead. There's always something to do!

Hope I've been helpful. Your on-line coments and suggestions are always
appreciated...off-line too.

73,
Roger, K2JAS
Morganville, NJ
Just about half-way between NYC and Philly!

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