[TowerTalk] Wire lubricant for cable pull thru conduit

Tue Feb 26 14:18:17 EST 2013

Dick-

On my 3" conduits, I used a spinning reel at one end, with the 6# test
fishing line tied onto a Safeway plastic shopping bag.  Duct taped the hose
from the shop vac to the other end of the conduit and turned it on.  The bag
arrived with the fishing line in about 3 seconds.  Then I tied some larger
rope onto the end of the fishing line and reeled it back to the other end.

73,
Steve
N6SJ

-----Original Message-----
From: TowerTalk [mailto:towertalk-bounces at contesting.com] On Behalf Of Dick
Green WC1M
Sent: Monday, February 25, 2013 11:32 PM
To: 'Dick Dievendorff'; towertalk at contesting.com
Subject: Re: [TowerTalk] Wire lubricant for cable pull thru conduit

Hi Dick,

I would second all of Jim's answers. A few extra points:

1. You can get a 3" foam mouse at your local electrical supply store (the
one local contractors use). Home Depot might have them, too. Tie some strong
but light nylon cord to it, and pull it through with a good high-horsepower
shop-vac sealed to one end of the conduit. Alternatively, you can make your
own mouse out of foam rubber and maybe some cardboard and a small eye bolt.
You should put the spool of cord on a dowel or something similar so it can
spin free while feeding the cord. You can slide the dowel between the legs
of a small step stool or ladder to support it. Once the mouse makes it to
the other end, remove the mouse, tie your pull rope to the cord, and pull
the cord back through. Of course, the spool of rope needs to be supported so
it can spin and feed the rope freely. This is how the pull rope was
installed in my three conduits -- 4", 2.5" and 1" -- which are 265' long
with 90-degree sweeps at both ends and a 90-degree turn about 2/3 of the way
to the tower. No problem at all. I was amazed by how fast that mouse made it
from one end to the other!

2. I've used a couple of different varieties of synthetic rope as pull rope.
What I like best is the plastic-like stuff that doesn't stretch much. I
think it's the rope rated for marine applications. You don't want the
cloth-like stuff that stretches a lot. If you use that for the rope you
leave in the conduit for future pulls, it'll absorb water and might rot (see
my last point below.)

3. The need for lubricant varies. Initially, my 4" conduit only had two runs
of 1/2" coax. No lube needed to pull those, even with the long length and
the 90-degree bend. The 2 1/2" conduit was more packed. As I recall, there
are five or six 8-conductor cables in it, ranging in size from heavy-duty
rotor cable to small Cat5-like cable for switching. No problem pulling that
bundle with no lube, either. The 1" conduit has three runs of #10 THHN
electrical wire for a crankup tower (no longer my main tower), and again no
lube was used to pull them. About a year ago, I removed the two 1/2" coax
runs and replaced them with two runs of 1/2" heliax (Andrew LDF4-50). I
bought something like 6 or 7 quarts of pull lube at home depot. I opened one
of the quarts at the house end and positioned myself at the tower end. A
friend fed the two cables at the house end (the cable was unrolled
completely and laid out in the yard because it wasn't on a spool. If your
sweeps are in place, you definitely need someone to feed the cable bundle
because it has to be lifted overhead and fed down into the conduit. Well, I
started hauling on the pull rope. There was a fair amount of resistance at
first, but then it started moving (I ran the rope through a pulley attached
to the utility box panel so I could pull horizontally instead of standing on
a ladder and pulling the rope straight up.) I kept pulling and pulling,
expecting that at some point my friend would call me on the HT to tell me to
stop pulling so he could open another bottle of lube. But pretty soon the
head of the heliax bundle appeared at my end of the conduit. I went back to
the other end and asked my friend how much lube he needed. He said I pulled
the cable through so quickly that he never got a chance to apply any lube at
all! I ended up returning all but that one open bottle of lube for a refund
at Home Depot. YMMV, of course. I would be prepared with enough lube to do
the job, but don't open all the containers. Home Depot carries several
different kinds, and I believe some are explicitly rated not to dry out or
harden. Check the label.

4. The subject of water in the conduit comes up a lot on TowerTalk. The
general consensus is that water is going to get into your conduit no matter
what you do. I thought that didn't apply to me because my conduit was
professionally installed and there's never been any sign of water at either
end in over 15 years. Well, when I pulled that 1/2" coax out a section of it
was wet. The wet section was about 1/3 of the way to the house, right where
the conduit makes the 90-degree turn. That must be where the leak is. 2/3 of
the conduit runs down a steep hill to that bend, and then the conduits
slopes up gently to the tower the final third of the way. So I think the
water just pools at the bend and hopefully, leaks back out into the
surrounding soil. Some people drill weep holes in the conduit to let the
water drain, and I believe some have actually used irrigation tubing instead
of conduit. You can search the TT archives for all the talk about that you'd
ever want to see.

Hope this helps.

73, Dick WC1M

> -----Original Message-----
> From: Dick Dievendorff [mailto:dieven at comcast.net]
> Sent: Monday, February 25, 2013 3:08 PM
> To: towertalk at contesting.com
> Subject: [TowerTalk] Wire lubricant for cable pull thru conduit
> 
> I’ve never run anything through conduit before.
> 
> 
> 
> I have a 100 foot long 3” conduit between house and tower, and in that 
> conduit I hope to run two ½” coax cables, three 3-wire ROMEX cables 
> carrying 24V for three different rotators, two 8-conductor (CAT-5 
> like) cables for an antenna switch, and three two-wire cables for the 
> rotator position indicators.  It’s a good-sized bundle.  There are no 
> 110 AC power lines in the bundle.
> 
> 
> I think I need to pull all this at once, with lubricant, and include a
> length of pulling rope or tape in the bundle for “next time”.   I
> believe
> that I want to pull these through all at once  in order to avoid risk 
> of damage to cables already installed.
> 
> 
> 
> What’s the right sort of lubricant for this?   What quantity should I
> buy?
> 
> 
> 
> I have some light nylon “fish” cord that I think I can pull through 
> with a small wadded up plastic bag and a shop-vac.  After I have that 
> pulled through, I assume I attach it to a hefty pull cord. What sort 
> of pull cord should I be shopping for?
> 
> 
> 
> Any tips on tying the “bundle” to the cord so that I have a smooth 
> thing to pull?  I have Kellums Grips suitable for ½” coax, but not for 
> anything else.
> Is this a “pulling eye”?
> 
> 
> 
> I presume I want one person on each end that can communicate, one to 
> feed a smoothed bundle in one end while the other pulls.
> 
> 
> 
> Should I tape the whole bundle together every few feet?
> 
> 
> 
> Thanks,
> 
> 
> 
> Dick, K6KR
> 
> 
> 

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