Are Galvanized Fence Posts Sealed?

Galvanization Process

• Galvanization is the process of coating metal in a thin layer of zinc. The zinc is applied electrostaticly or by submerging a metal fence post in molten zinc. Besides providing a physical barrier, galvanization also offers chemical protection since zinc resists and neutralizes corrosion. Iron and steel fence posts benefit most from galvanization, which is not an appropriate sealing method for wood or other type fence posts.

Protection

• Because the zinc used to galvanize fence posts resists rust, it forms a protective barrier even if it doesn't completely seal the metal beneath it. If you purchase galvanized fence posts but drill holes into them to insert a latch or hinge, drilling through the zinc layer exposes raw steel or iron, but doesn’t remove the protection that the zinc provides. This is different from painted fence posts or those sealed with an acrylic sealant, which only provides surface protection but does nothing to protect nearby exposed metal.

Benefits

• Besides providing physical and chemical protection, galvanized fence posts offer additional benefits. Galvanization creates a durable protection layer since zinc bonds to the metal fence post better than paint or other sealants do. This means it lasts longer and requires less maintenance. Galvanized fence posts eliminate the risk of a weakened fence due to rust. They also preserve a fence's appearance.

Sealing Options

• Even if you have galvanized fence posts, you may still choose applying another type sealant for additional protection or decoration. A layer of outdoor latex paint lets you color fence posts to match your home or a color in your landscaping. Do not to sand the galvanized posts before applying the paint, since this removes the zinc and makes the posts more susceptible to rust once the paint wears off. Clear sealants are useful for areas where the galvanization wears off after extended exposure to the elements.