Fish Tape

[Ben]

Is there a big difference between nylon and fiberglass (besides price)? I've never used it, but I need to buy some. I'm running about 40' of RG8 coax, including through about a 4" 180 deg bend that's pretty filled with some other wire and cable, then through a false ceiling.

[Scout26]

Lube, lots and lots of lube.

[AJ Dual]

Lube, lots and lots of lube.

This.

Friction on cables seems as if it were exponential based on the length of the run. 

The more rigid fiberglass fish tape is going to do that (is there a term for this?) flop and flick around better on it's end as you twist the thing to try and navigate the turn, and once the tip catches the turn, you'll have more rigidity to push it through.

[Ben]

What kind of lube?

Luckily (maybe) the 180 I have to deal with is on a roof and the first and only funky thing I think I have to go through. It should be just navigating a couple of easy turns in the false ceiling once I'm past that. Of course I guess the 180 will also be the last thing I have to deal with when I run the cable up. I think it might be around two feet long, shaped about like a candy cane.

[AJ Dual]

What kind of lube?

Luckily (maybe) the 180 I have to deal with is on a roof and the first and only funky thing I think I have to go through. It should be just navigating a couple of easy turns in the false ceiling once I'm past that. Of course I guess the 180 will also be the last thing I have to deal with when I run the cable up. I think it might be around two feet long, shaped about like a candy cane.

They sell big pump jars, small squirt bottles, and sometimes whole buckets of wire pulling lube in the electrical aisle of most big home centers. It's water based, or polymer/Teflon based stuff that's supposed to eventually dry out and leave very little residue. And not degrade common insulator or wire cladding materials. Or if it does leave a film behind, it's by design to make the wire a bit more slippery if you ever need to pull it out, or if another wire is someday pulled past that one...

Usually it's clear stuff that looks like hand sanitizer.

Wait... this 180 deg bend.. Is it conduit/pipe, or some other kind of void with lots of clearance?

Generally the lube we're talking about is for pulling wires through pre-laid conduits, or open voids and racks, if there's LOTS of wire already in there that might be on top of what you're trying to pull through...

If this is an otherwise clear structural duct or void of some sort, then no lube may be required. Just be aware that cable pulling lube exists, should it prove that you do need some to make the run you want. 

[Ben]

Thanks AJ! I'll look for the lube when I get the tape.

The 180 is pipe IIRC - it's at an island Navy installation I work at sometimes so I can't remember the material for sure. All the other wires running through are either coax of some sort or cat5. From what I remember from my last look was that there was still a bit of wiggle room left for more cabling. I'm pretty sure if I can navigate that, I'll be home free, but I think the lube could come in handy even for that relatively short part of the run.

[Boomhauer]

Ill never forget the day i walked into my local gun store to see the owner squirting a big bottle of lube into what looked all the world like a sex toy. He was filling his Thompson Machine suppressor with wire pulling lube...

[Tuco]

A 180 degree bend should be pretty easy.
One-eighty elbow, on the other hand, ought to have a pull box on it.

[Perd Hapley]

Huh. I didn't know there was any kind of fish tape, but steel.

[RoadKingLarry]

If it's a conduit you may have o work again when you pull the cable pull a pull cord with it.

About a dozen years ago I was pulling cat-5 for a rural school. The pull was through a mostly empty 4" conduit so it should have been easy.
If there hadn't been a dead rat in the conduit it would have been. I was feeding the cable and the guy pulling got a handful of squishy dead rat. He painted the floor. 

[never_retreat]

Fiberglass tapes tend to be stiffer than metal. So easier to get through a big stuffed pipe. They do not work well in small pipe and tend not to have the tensile strength metal tapes do.
Always use a fiber tape if working with pipes and equipment that are energized.

[RocketMan]

Hmmm....mixing CAT5 and coax for RF in the same conduit...could be asking for trouble.  That is assuming the RG8 is for RF in this application.

[Ben]

Hmmm....mixing CAT5 and coax for RF in the same conduit...could be asking for trouble.  That is assuming the RG8 is for RF in this application.

I'm using double shielded so I'm hoping not. :(

IIRC there are only two cat5s running through it coming from the same microwave dish, the rest are coax and should all also be double shielded, unless somebody slacked off. I'm basically installing a dupe system to something that's already there, and the first one has as of yet not had any interference issues that I could tell.

[AJ Dual]

Huh. I didn't know there was any kind of fish tape, but steel.

Spring steel is great for new construction, or if it's a very first run, and you're only pulling a bundle of pull-strings for later use.

But steel can be a major PITA at best if it cuts low voltage comm wires, or even breaks some fiber, and deadly at worst if it shorts something if you're working among existing wires.

[K Frame]

Yep, steel is for new pulls through empty conduit ONLY.

Years ago a friend of my Father was working on his old house and pulling through existing conduit.

The tape and wire shattered off the old tar and paper coating on the old wiring that had been put in the in the 1920s or 1930s.

When he flipped the breaker back on, it electrified the conduit throughout the house, caused multiple shorts, and two fires.

He ended up rewiring the entire house.