When damage occurs to one or more of your metal garage door's panels, you may not need to replace the door panels. With the right tools and some auto body repair products, you can repair the damage done to your garage door. Here are instructions to help you complete these repair projects.

Remove Rust

Under the right conditions, rust can begin to form on the surface of your metal garage door. If you don't remove and repair the rust spots, the rust will continue to erode the metal of your garage door and lead to further and more extreme damage. It is best to remove the rust as soon as it begins to show to avoid any further damage necessitating the replacement of an entire panel of your garage door.

First, sand off any surface spots of rust, using a coarse sanding block or an electric hand sander. Be sure to remove any loose rust and flaking paint from around the rusted areas down to the bare metal of your garage door so you can complete the repair properly. Leaving any rust on the metal will allow the metal to continue to erode, even after you have repainted your garage door.

To remove any rust in hard-to-reach areas, such as holes or dents, you can use a rust removal product to help you remove the rust. Apply the liquid and allow it to sit on the rust for the product's recommended time, then dislodge the rust with a wire brush. Use a damp cloth to remove any rust residue, and allow the cleaned and rust-free areas to dry completely before applying any filler, primer, or paint.

Repair Holes

Holes in your garage door can happen due to many reasons. Rust forming on your metal door can etch into the metal layers, creating slight holes that need to be filled. A vehicle or other heavy object can impact your garage door, leaving a hole.

Holes From Rust

To fill holes caused by rust damage, follow the above instructions to remove the rust, then clean the surface of the door with acetone or rubbing alcohol. Apply an amount of liquid metal epoxy filler into the hole. Make sure you overfill the hole, then use a putty knife to remove the excess filler and smooth the surface of the door.

If your garage door has a wood grain texture, use the smooth end of a pencil's eraser to create the wood grain grooves in the garage door. Allow the filler to dry, following the package directions. If your garage door has a smooth finish, smooth the epoxy-filled area with a fine-grit sandpaper. 

Holes From Objects

To repair larger holes in a garage door caused by a vehicle or other object, first, sand off the paint from the damaged area to expose bare metal and wipe down the surface with acetone or rubbing alcohol. If there is a large void in the garage door, you can fill it with spray foam insulation. Direct the spray insulation into the hole within the door's paneling until it fills in the hole. Scrape off any excess spray foam insulation with a wide spackle or putty knife. Allow the spray foam to harden according to its package directions.

Now you can patch the hole with auto body filler. Keep in mind, once you mix up your auto body filler for use, you only have about four minutes before it will harden. So, it can be helpful to mix up the auto body filler in smaller batches as you need it for repairs.

Combine the auto body filler with its accompanying hardener and apply it onto the hole in the door, overfilling it around the hole at least one inch on all sides. Then, use a putty knife to scrape off any excess. Check the filler after 30 minutes to see if you can scratch it with your fingernail. If it has fully hardened, your fingernail will not affect it. When it is fully hard, sand it with a medium-grit, followed by fine-grit sandpaper. 

Now you can finish your garage door repair by applying a rust-inhibiting primer and paint. Contact a garage door repair service for assistance.