Suck a Pull String Through Conduit With a Vacuum, Then Pull Your Wire
The Problem
Getting wire through a run of conduit is the fight — a fish tape hangs up on bends and couplings, and pushing wire directly stalls after the second elbow. The wire was never the right thing to send through first.
The Technique
Let moving air do the routing.
- Feed a length of light string into one end of the conduit — a few inches is enough to start.
- Put a vacuum on the other end of the run and seal it to the conduit opening as best you can. Purpose-made suction nozzles exist for this, but a shop vac hose held tight to the opening works.
- The airflow snatches the string through the run — around bends, past couplings, out the far end in seconds.
- Tie your wire (or a proper pull rope, for heavier pulls) to the string and pull it back through the conduit.
The string weighs nothing and has no stiffness, which is exactly why it travels where a fish tape fights you: it doesn't push against the bends, it rides the air.
Pro tip: If the bare string won't catch enough air on a big-diameter conduit, tie a scrap of plastic bag or a bit of foam to the leading end as a sail — electricians call it a mouse. And for a long or heavy wire pull, use the string to pull in a rope first, then pull the wire with the rope: two easy pulls beat one hard one.