Fishing into existing nailed-on plastic box

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JoeNorm

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I have read every thread on fishing wires and have done my own fair share in the field.

Is there a consensus on the best way to fish into a plastic receptacle box from above or below? Is it alway best to just remove it entirely and replace with a remodel or is it easy enough to get the wire in there with it in place.

I have read some guys alter the box quite a bit, cutting it or drilling a hole, wouldn't this void the listing of the box?

Thanks
 
I can usually hit the box with the fish tape, cut a small slit in the wall just above or below the box, then use another small hook tool made from the fish tape to guide it into the ko
 
I cut a slot above or below the box in the drywall, just shy of the plate line, and beveled away from the box so the back of the slot is wider. If a KO isn't handy, I'll drill a new hole in the box near the front, to one side of the screw boss.

With the tip of the fish tape or rod hitting the box (a helper with a phone or walkie-talkie comes in handy here), I'll use the teeth of the drywall saw, needle-nose pliers, a hooked wire, or a combination to guide it to the KO or new hole.

As a side note, I also make sure to add the new EGC to the others in a way that it's short enough to keep the cable from ever being pulled back enough to allow the stripped sheath to leave the box and expose the individual wires.
 
roger said:
In the real world many listings have been altered.
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Technically the listing deals with how the product was manufactured, therefore it can not be changed in the field.
What we can do, however, is apply the product in a manner inconsistent with its listing. It is up to the AHJ to pass judgment on any installation.

Of course, I am like most people and do talk about a listing being violated.
 
ADI sells a product for fishing called a wet noodle. It consists of a length of solid #4 al conductors bendable, with a magnet at each end molded into the outer insulation of the tool. Also they give you a chain that is pretty weak for using to pull NM cables mostly it was designed for alarm wiring , so I use my own much stronger chain. Use a screwdriver to knock the opening in the back of the box , stick the fat side of the magnet stick up into the wall thru the hole, and then go up into attic and drill the drop hole thru the top plates and let the chain down. It will usually find the magnet since it is a rare earth magnet and pretty strong. Go back down and pull the magnet stick back out of the hole with the chain following you. Hook the NM to the chain and go back to attic to hoist up the cable into the attic. ( or down to the crawl space under the house) . I am really good at doing this procedure.
 
macmikeman said:
Also they give you a chain that is pretty weak for using to pull NM cables mostly it was designed for alarm wiring , so I use my own much stronger chain.
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I use the noodle to pull in a stronger pull string if there's too much friction for it.

I also added a 2" split key ring to one end of it so it can't fall through a hole.

Hook the NM to the chain and go back to attic to hoist up the cable into the attic. ( or down to the crawl space under the house) .
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Don't you find it to be easier to pull toward the box? 6 inches into it rather than 5 feet through it?

I am really good at doing this procedure.
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Same here, but a helper sure helps, especially with my OEM left hip; aftermarket replacement in 8 days!

"If you want to know the easiest way to do a difficult job, ask a lazy person." :giggle:
 
JoeNorm said:
I have read every thread on fishing wires and have done my own fair share in the field.

Is there a consensus on the best way to fish into a plastic receptacle box from above or below? Is it alway best to just remove it entirely and replace with a remodel or is it easy enough to get the wire in there with it in place.

I have read some guys alter the box quite a bit, cutting it or drilling a hole, wouldn't this void the listing of the box?

Thanks
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Technically you need a method of clamping that cable to the box after it is fished in, many don't do this with typical nail on non metallic boxes though. If you remove existing box and replace with a remodel type box, it will have clamps.
 
I think it's going to depend on the situation. Sometimes cutting the box nails with a sawzall and replacing the box with a smart box is easier than trying to go fishing 🎣.... If not removing the box is prudent for some reason, sometimes I will drill a large 2" hole in the top or bottom plate then you can see right into the box ko and drop a stick right into it (if there is no insulation of course).
 
electrofelon said:
I think it's going to depend on the situation. Sometimes cutting the box nails with a sawzall and replacing the box with a smart box is easier than trying to go fishing 🎣.... If not removing the box is prudent for some reason, sometimes I will drill a large 2" hole in the top or bottom plate then you can see right into the box ko and drop a stick right into it (if there is no insulation of course).
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my luck is most walls were insulated
 
Seems to me a 2" hole in the top plate is a bit of overkill for a cable that is typically 1/4" x 1/2" . I will sometimes drill two 3/4" ones side by side and shine a mag light thru one while sending a glow rod down to the box ko.
 
Just cut the old nail on out and put in an old work plastic problem solved or toe screw the one you took out


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I just fished romex into four 100-year old knob and tube boxes in my house without cutting into any drywall lathe and plaster (or wallpaper!) at all.

I was able to drill a hole from the unfinished floor below in all cases. Very carefully lined up.
Used a thinner more bendable fish-stick and managed to poke into into the box from below in all cases. Used a hook made of solid #14 copper in a couple cases to grap the fishstick into the KO in the box. Took between 2-5 tries on most of them. Solid copper wire could probably work just as well as the fishstick in a lot of situations.
Taped nylon string (you could use conduit measuring tape) to the fishstick, brought that down to the floor below, and then taped the romex to the string to pull it back up. Very flexible. Don't try to use a fishstick for actually pulling the cable.
Checked romex for damage, no issues.
This even worked on on a box that was on an outside wall of a bay window without the story underneath. Drilled hole below from outside, drilled through side joist of the story underneath, used mostly #14 copper to get the string through the right angle in the void under the bay window. Little stucco patch, no problem.

The hardest part was prying out the old 3/8" KOs on the metal boxes from the inside, when they were supposed to be knocked in from the outside. Shouldn't be a problem with plastic boxes.

(And yes, my romex that's all inside the walls does not have proper clamp connectors to the old-as-hell boxes. Oops.)
 
jaggedben said:
(And yes, my romex that's all inside the walls does not have proper clamp connectors to the old-as-hell boxes. Oops.)
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If it's a regular job you can use these or similar

1/2 in. THE INSIDER® Nonmetallic Sheathed Cable Connector | 4714 | Raco

1/2 in. THE INSIDER® Nonmetallic Sheathed Cable Connector
www.hubbell.com www.hubbell.com

If it's a smaller hole like would be typical for a knob and tube box, I usually drill and tap it for a cable clamp robbed from a modern box. (Probably going to have to drill and tap a ground screw in there too).
 
Hollow walls - Jack chain dropped from the top plate used with a piece of #12 THHN with a hook through the box to catch the chain.
Insulated walls - Glo-rods with a hook on the end catching it with same method as above.
Note: If you have a tape measure that the end broke off, don't throw it away. It cuts through insulation like butter!
 
Rick 0920 said:
....Note: If you have a tape measure that the end broke off, don't throw it away. It cuts through insulation like butter!
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Absolutely! You can't imagine how good this trick works till you try it. Put a little electrical tape on the end where the hook used to be so it doesn't get sucked up into the case.

Probably don't have to mention using the tape since electricians put tape on everything.
 
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