So I made a mini-rooter out of: (list of materials coming up...)
* Safety glasses and snug fitting gloves (you don't want them getting wrapped up in the spinning tape)
* piece of electrician's flat steel fish tape (I had one I'd found at a job site with the handle gone and the tape sprung out) (Incidentally, this material is useful for many purposes being tough but flexible. It will take a sharp edge and hold it for a while as long as you don't overheat it while sharpening)
* drill (in this case a cordless one...not crazy about standing in a pond with water up to my knees and having a live tool in my hands.)
* piece of flexible electrical conduit as a guide for the fish tape
* pair of pliers
This process should work in any small diameter pipe. Just be aware that metal WILL cut plastic and you don't want to compromise your piping any more than it already may be.
Step 1: Cutting Edge Technology
2. Sharpen one end carefully on both sides and the end. You do both sides so that you can reverse direction and still cut.
3. Carefully make a slight bend at the end. Not too much otherwise it may be hard to negotiate bends etc.
4. Feed the tape into the conduit or pipe as far as it will go, then slip the flexible conduit over the exposed section then chuck it up in the drill. The conduit itself will act as a guide for the section already in, and the flexible will support what you will be feeding in.
5. Very slowly start the drill (in either direction and make sure that the tape is actually spinning. If you need to back it out a little before the obstruction and get it going first, do so, then slowly advance it while it is turning.
6. When you have fed it in as far as the flexible conduit will allow, if you want to go further, you can either use a shorter piece of conduit for a support or try and just carefully (with gloves!) hold the tape loosely and feed it in some more.
7. Reverse the drill and spin it slowly while backing it out.
**A note of caution: the tape may be twisting along its length without actually spinning and if you go too far without it actually spinning, you could snap it off in the conduit then you'd be double screwed....
Step 2: Check for Success
In this case, I used a second fish tape from the niche, all the way to the junction box and pulled a rope back to use for the new light cord.
Step 3: Done!
In this case, I attached the rope to the end of the new light cord and pulled it back up to the junction box. I cut the cord to length and spliced it into the feed, put the cover back on the j-box and cleaned up.