Driving 3″-4″ pipe for corner posts is quite popular in our area. It used to be our choice before we began using Hedge for our corner posts. Pipe can be driven even in rocky ground and will last at least 20 years. For some reason when we were using pipe for corner posts we also switched from using bullnose corner insulators and began using wrap-around insulators. Turned out to be a mistake as we’ve found the wrap-around insulators on a pipe corner will often split and crack allowing for quite a short. They work fine on a larger wood posts but the smaller arc of the pipe corners seems to cause them to fail and when we do replace the wrap-arounds with a bullnose insulators we find the high tensile wire inside the wrap-around is often corroded.
You’ll see in the photo how I temporarily fixed a split wrap around–stuck a no kick [insulated handle] between the post and insulator to keep it from arcing to the corner. If you look closely you will see the cracks in the insulator. This is an old fence which we plan to replace soon so I used this very ugly but quick method to fix the short.
We have quit using wrap arounds. I’m not really sure why we began using them in the first place as a bullnose corner insulator is easy enough to attach and will last 20 years.