Found a trick for pulling wire through tight conduit in an old building

I was working in a 1920s building downtown last month, trying to pull 3 new circuits through a 3/4 inch conduit that had two 90s and a 45. I tried lube and a fishtape but kept getting stuck at the second bend. Finally I taped a strong magnet to the end of my fishtape and used another magnet on the outside of the conduit to guide it past the tight spots. It worked on the first try after that. Has anyone else used magnets for tricky pulls like this?

3 comments

3 Comments

mary_west1mo ago

The 1920s buildings around here can have that old rigid conduit where the inside gets all gummy from decades of heat cycling. One thing I noticed you didn't mention is checking if the conduit is actually continuous all the way. I had a job in a 1930s school where we found a coupling had come loose inside the wall and the ends were just butted together with a gap. That magnet trick is clever though, I bet it also helps if there's any metal shavings or old wire fragments stuck in there from previous pulls. Just be careful with strong neodymium magnets near electronics, they can mess up meter readings if you get too close.

betty_kelly91mo ago

@spencer_park26 must have been fun finding that wire noodle mess behind the joist.

spencer_park261mo ago

Man that's a good point about the coupling coming loose lol. I had something similar happen in an old warehouse where we pulled wire and it just stopped halfway through, turns out the conduit had separated behind a joist and the wire was just piling up in the gap. The magnet trick would've saved us a lot of cussing that day.