Measure the outside dimensions of your wooden fence post with a measuring tape and purchase a finial or fence cap of the appropriate size. The fence cap is a sleeve that fits on or over the top of the post. Some finials are designed to fit right on top of a post and don't need a fence cap.
Drill a hole for the all-thread (screw threads at both ends) into the center of the bottom of the finial. Screw the all-thread half way into the finial. All-thread is a screw with threads on both ends so it will hold two pieces of wood together.
Drill a guide hole for the finial all-thread directly through the center of the fence cap and into the top of the fence post. Make sure the fence cap is exactly centered or perfectly flush with the post on all sides before you drill the hole. The drill diameter will be different depending on the size of the all-thread you use in the finial.
Screw the exposed all-thread on the finial through the fence cap and into the top of the post. Rotate the finial clockwise to screw it onto the fence cap. This will fix the fence cap and finial in place. You can also use a strong waterproof glue between the fence cap and the post top and between the finial and the fence cap.
Measure the outside dimensions of the post where you want to place a metal finial. Cast iron fences are made with specific post dimensions, according to Fence Supply Source, an online fencing retailer. Purchase a finial to fit the metal post.
Place the metal finial on the fence post and press it down onto the top of the fence post. Many metal finials have sleeves that slip over the top of the fence. More complicated finials have to be placed according to manufacturer's instructions .
Tack-weld around the base of the finial to join it to the fence post. Use the welder, welding rod and flux to permanently attach the finial to the post. Welding instructions are specific for different types of metals and only expert welders should attempt welding metal finials.
Joint a metal finial to a post with glue. You can also use a strong glue or epoxy to joint a cap-fitting finial to a metal fence post if you don't have access to a welder. Put a dollop on top of the post and press the finial down on top of the post.
Finish the joint. If you are an expert welder, you are done. If not, you might like to file or debride the welded seam between the finial and the post for a finer finish. If you glued-on the finial, wipe off any excess drips.
Things You Will Need
- Measuring tape
- Post cap
- All-thread screw
- Waterproof glue
- Drill and bit
- Welding torch
- Welding rod
- Find the center of a square finial by drawing lines between opposite corners. The center is where the lines intersect.