- Thread the cap onto the pipe.
- Tighten the cap. Fit one pipe wrench just below the threaded end of the pipe on the left-hand side, and fit the second pipe wrench on the right-hand side of the cap. To get the best leverage on the wrenches, there should be no more than a 15-degree arc between the two handles. Pull the handles of the wrenches together. Repeat until the cap is tight.
- Turn the capped pipe upside down, and apply a mild corrosive to the seam between the cap and the pipe. For this application, a commercial thread adhesive or a carbonated cola drink poured over the exposed threads will work.
Things You Will Need
- 3-foot section of 3-inch I.D. steel pipe, threaded on one end
- Threaded cap for pipe
- Two large pipe wrenches
- Mild corrosive
- Applying a thread adhesive to your post driver will prevent the cap from working itself loose while driving posts.
- Use heavy-gauge steel only. Driving posts will put a great deal of stress on the driver. Many low-cost post drivers will fail after only a few posts.
- Welding handles made of rebar above the center of gravity on your driver can make driving large numbers of posts easier.
- A short section of an old drive shaft, if you can find one, will work well as a post driver.