A good flagpole will last for decades; most are made of metal so after many years it need its finish repaired. Flagpole hardware will also eventually need tightening, or replacing. The flagpole may need to have the rope tightened or replaced, or the flagpole may need to be reset and straightened. Regardless of what repair needs to be made the flagpole should be taken down and set on saw horses before repairs are made. Set it up outside as flagpoles are long and will not fit in most workshops.
Set up the saw horses by placing them as far apart as the pole is long. Place two saw horses, one in front of the other on each end if you have a very long pole. Place the flagpole on the saw horses so that each end on the pole rests on the saw horses, and extends beyond the horses by about 4 feet. Nail a small piece of wood to the saw horse on each side of each end of the flagpole. Do this to prevent the pole from rolling off of the saw horses while you are repairing it. Do not squeeze the pole too tightly with the blocks as you will need to be able to rotate it. Remove the rope and hardware if they will be replaced, use newspaper and tape to cover them if they will not be replaced.
Plug in a 100 foot long heavy duty extension cord then plug your electric handheld sander into it. Sand the entire top half of the pole using the electric handheld sander and a medium grit sandpaper. Turn the pole so the bottom half can be sanded. Switch the sandpaper to a fine grit and sand the bottom half of the pole again using the fine grit. Rotate the pole when you are finished then sand that side using the fine grit. Remove dust and residue by wiping the entire pole down thoroughly with soft cloths.
Hold a can of primer 10 to 12 inches away from the surface of the sanded pole, beginning at an end of the pole and apply one coat of primer to the top half of the pole, from end to end. Allow the top half to dry 15 minutes then rotate the pole so you can spray the bottom half. Allow the bottom half 30 minutes to dry.
Apply a coat of exterior enamel spray paint to the top half of the pole, holding the can 8 to 10 inches away from the pole, spraying in a left to right motion. Begin at an end of the pole and work your way to the other end. Allow the first coat of paint 30 minutes to dry. Rotate the pole and apply the paint to the bottom half. Allow it to dry 30 minutes then rotate the pole and do both sides again. Allow the final coat 12 hours to dry.
Remove all painters tape and newspaper if you used it. Use a screwdriver or wrench that fits the hardware for your flagpole to install new hardware. Line up the holes in the hardware to the holes on the pole, then insert and tighten the screws or bolts. Tighten existing, not replaced, screws or bolts one-and-a-half turns, as they loosen slightly over the years.
Unwrap your new rope and find the end of it. Take the end of the rope to the hardware at the top of the pole. Start the rope and let the rope unravel as you put it on the pole. Use a thick water- and weather-resistant nylon rope so you will not have to replace it again in a couple of years. Attach the rope to the hardware on each end of the pole, then tie it tightly so there is as much tension as possible. Do this so the rope will not be sloppy on the pulleys.
Dig the flagpoles hole to be at least 2 feet deep, 1 1/2 to 2 feet wide. Use a post hole digger, commonly used for installing fence posts, or a small pointed shovel. Set the flagpole's bottom piece, the ground set, into the hole. Set the bottom of the flagpole directly into the hole if you do not have a ground set piece, making sure you have a friend or two to help hold it as you put the braces up. Use a 3-foot level on the side of the pole. Adjust the pole until it reads level and then put one 2-by-6 brace on each side of the pole. Think North, South, East and West. Insert 6-inch screws, one on each side of the board, through the board and into the board on the other side of it. Have someone holding the pole, keeping it straight and level then inset the other two screws through the other two boards to hold the together. Fill the hole with concrete and allow the braces to remain until the concrete is set. Allow the concrete to set at least 16 to 24 hours before raising a flag or putting the pole into the ground set.
Smooth the dirt loosened from digging over the set concrete. Sprinkle as packet of flower seeds around the pole, in the fresh dirt to avoid a weed problem at the bottom of your pole in the future.
Have friends to help you with this project as a flagpole is quite large and difficult to work with.
Wear eye protection and a face mask while sanding and painting. Use caution when moving any long, large object.