One trick that can be used for fishing stuff through long lengths of conduit is the suction and / or blow approach - it is often used by people needing to fish telecom cable through conduits, and can be used in all sorts of other applications...
Equipment -
1. Good shop vac (must have high volume as well as good suction), and / or high volume, moderate pressure compressed air source - really long runs or big bore tubes could use both.
2. Roll of poly or nylon "masons string", or similar. I like mason string because it's very strong for its size, and it dispenses very nicely of the spool. Must be at least as long as the pipe run.
3. A "puff" - some sort of soft, easily deformable item that will fit loosely inside the pipe, so that it will slide through easily, but block most air flow around it. On small pipes a wad of paper towels works well, I've also heard of people using chunks of soft foam (think something like a "Nerf" ball) The tighter the fit the better, but the puff MUST be free to slide, so don't get it overly tight...
4. Means of connecting the pressure / suction source in #1 to the pipe, and sealing around the end - could be as simple as your hand, or something like a bunch of rags, depends on the relative sizes.
Technique -
1. Attach puff to end of string
2. Stuff puff into one end of pipe
3. Hook vac to other end of pipe, and / or pressure to the same end, turn on...
4. Catch puff as it comes out other end... (Note, if using a vac that is bigger than the pipe, check often, as it is really easy to suck up the puff and a LOT of string before you know it... (Don't ask how I know... :red: )
5. Use string to pull the content, or if needed a heavier intermediate pull rope.
If I'm going to be making multiple pulls in the same conduit, I will often make my pull string twice the length of the run, plus a bit extra. I then tie each end to a solid anchor, and attach the pull in the center of the string - I can then just shuttle the middle of the string back and forth for each pull. When I'm done, I will just make a little bundle of the extra string and leave it in place in case I ever need it for future use.
This is MUCH cheaper and easier than dealing with long fish tapes...
Gooserider