Often there is some confusion about painting a steel door. Many homeowners have heard about the problems associated with painting pre-primed steel doors. Some of these problems are excessive peeling of the paint on the door or frame and difficulty to hide brush strokes on a smooth surface.

Most problems with painting a metal door are preventable and stem from lack of knowledge about the factory primer and the proper steps involved when painting a steel door. Another factor that will affect the life of the paint is the color and the use of a storm door, follow the manufactures recommendations.

Insulated steel entry doors are a great life long purchase and if painted correctly can be virtually maintenance free for many years.

General Procedures for Painting a Steel Door

Most of the work involved when painting steel doors is with the preparation. This is true even for a new, unpainted, steel door. The beauty and longevity of your steel door is dependent on the following procedures. These apply to the frame and trim as well.

1) Remove Hardware and Weather Stripping

No matter which painting method you use, remove all the locking hardware from the door and frame, including strike plates. Brushing around these items is difficult and time consuming. Other items to be removed can be kick plates and doorknockers. Remove the hinges if you are painting a steel door detached from the frame.

Now remove the weather stripping. Many door manufactures have removable weather stripping. It simply pulls out of a grove in the frame. Remember how it came out for re-installation and store in a safe place.

If the weather stripping cannot be removed, stapled or secured in place, you can use a drywall knife to act as a shield while brushing the frame and trim. Otherwise apply masking tape for protection while painting.

2) Remove Excess Window Glazing

Doors with windows or sidelights need to have the excess glazing removed prior to painting. This caulking material will have emerged from under the window frame; can be a sticky compound or silicone caulk.

Use a new single edge razor blade and score the glazing next to the frame. Be careful not to cut the frame. Now remove the excess glazing by holding the blade perpendicular and close to the frame. Carefully scrape the glazing loose.

After the glazing is removed wipe the area clean with a solvent to remove any remaining film. Use denatured alcohol for silicone and mineral spirits if the glazing is sticky.

3) Clean and Mask

A clean surface is important while painting a steel door. Pay special attention to greasy fingerprints and general grime. Any mild cleaner can be used, rinse well after cleaning. Another cleaning method is to wipe the steel door and sidelights with a clean rag saturated with denatured alcohol. This will remove most types of surface contamination.

After the door is cleaned and dry, mask the glass and any other items not to be painted. The amount of masking depends on the painting method you use.

4) Fix Dents, Sand and Prime

Fixing any dents, sanding the entire steel door and priming are all vital steps. The amount of work at this stage depends on the doors condition and if the door is new or previously painted. Painting a steel door is similar to painting a car. Although the doors finish doesn’t need to be as good as a car, every dent and deep scratch will be highlighted after painting.

Repairing a Steel Door and Frame
Use auto body filler, such as Bondo, for dents and deep scratches. Before applying any filler, sand the damaged area with 80-100 grit sandpaper to help with adhesion. Mix the auto body filler according to the manufactures directions and try to slightly overfill the damaged area.

Allow the filler to dry completely then begin sanding to level and smooth it with the surrounding area. A vibrating orbital sander or a palm sander can be used for large areas. Small repairs can be hand sanded using a rigid sanding block and sandpaper.

Start with 100 grit sandpaper to remove most of the excess filler. Be careful not to sand too much. Continue sanding with 150 grit sandpaper, then finish with 220 grit or finer. Feel the repaired area with your fingers to check for ruff edges or deep scratches.

Spray on a small amount of primer to highlight any defects in the repair, an aerosol primer works great. Continue filling and sanding until the repair is flush with the surface and not visible after priming.

The same auto body filler can be used to repair the wood frame.

Repairing wood is basically the same as with the steel door. Remove all loose material, including peeling paint or rotten wood. Sand the area around the repair with 80 grit sandpaper to roughen the surface. Build the repair in layers if over 1/2 inch deep. Finish sand in the same manner as the steel door.

Finish Sanding
Sanding is a very important step while painting a steel door. After all repairs are finished, the entire door will need to be lightly sanded. This needs to be done on new and previously painted steel doors. Use 120—150 grit sandpaper or a medium-fine sanding sponge.

New steel doors need to be sanded to roughen the surface without causing deep scratches. Previously painted doors can be sanded to remove or lessen brush marks or paint drips. After sanding wipe the entire door with a tack cloth.

Now is a good time to sand the frame. New primed frames need be hand sanded with a medium-fine sanding sponge. Previously painted frames can be hand sanded if in good shape or power sanded with a palm sander to remove loose paint and heavy paint edges.

Priming a Steel Door and Wood Frame
It has been my experience that new doors need to be primed with a universal quick drying oil base primer before painting, such as Zinnser Cover Stain. This is especially true for the wood frame.

Previously painted doors and frames need to be primed only if the type of finish paint is a different type or if the previous finish is in bad shape. Acrylic paints shouldn’t be applied over oil base paint without priming first. Prime all raw wood on the frame as well as any exposed metal.

Use a universal quick drying oil base primer for all your priming needs. An aerosol primer can be used on the door, otherwise use the same procedure as when painting. Choose a good primer as the foundation for the finish paint.

Now is the best time to take a good look at all the work you have done so far. It will be impossible to fix anything once you have started painting. Painting a steel door can be time consuming, but with the preparation as perfect as possible the end result will be much better than the alternative.

5) Painting a Steel Door and Side Lights

Applying the paint is the most satisfying part of painting a steel door, plan on a minimum of one coat of primer and two coats of finish. You have three methods of application to choose from, brushing, rolling or spraying.

• Brushing Steel Doors – Probably the most popular way to paint a steel door requiring the least investment of tools. Achieving a truly smooth finish is difficult with this method, easier if you use a good professional paint brush.
• Rolling a Steel Door – An easy method to master requiring a minimal investment of tools. Excellent control is possible with the right size of roller frame and short nap roller cover. The finish will have a fine even texture from the roller cover, better than brushing in most cases.
• Spraying a Steel Door – If you want a truly smooth finish, using a paint sprayer is the only way to go. This method requires the largest investment of tools and time. Plus, a little experience using this equipment is a must.

 
The best finish is from spraying; either with an airless paint sprayer or HVLP sprayer but a steel door can be rolled or brushed. Rolling is a great alternative to spraying, producing a very satisfying finish.

On the other hand, brushing can be problematic producing brush marks on the smooth surface. Painting steel doors with a brush is best suited for doors with raised panels; flat doors should be sprayed or rolled. Choose an application method that best suits your abilities and needs.

Painting the Door Frame and Sidelights

The frame can be painted while waiting for the door to dry between coats of paint. Typically two different colors and types of paint are used, one for the exterior part and one for the interior. Concentrate on one color at a time.

Begin with the interior color, if the door has been removed from the frame for painting. The interior portion is the most difficult with the door installed. Otherwise, begin with the exterior color so the door will appear finished sooner.

Start painting the upper part first, the header, and then work down one side at a time. If the weather stripping was left installed use a 6-inch drywall knife to act as a shield to protect the weather stripping. Simply insert the knife between the weather stripping and the frame. Moving it down as you brush. Wipe the knife clean several times while brushing to avoid any paint build-up.

The door hinges and striker plate(s) can be protected by carefully covering with masking tape or removed if the door was uninstalled for painting.

Sidelights are typically painted with a brush but can be sprayed with the appropriate masking. The method you choose depends on the final outcome you want and your skill with a paint sprayer.

Steel Door Painting Tips

Although painting a steel door is an easy project for most homeowners, there are a few considerations that can drastically affect the longevity of the finish and the need to refinish sooner. Painting a steel door shouldn’t need to be done for 8—10 years if completed properly.

• The color you choose will affect how long the paint lasts. Dark colors will fade sooner. The worst color is red. Although the front door is a great place for a dramatic statement, a dark or red color will need repainting much sooner.
• Sun exposure will also cause the finish to fade faster. Steel doors can become quite hot when exposed to direct sunlight. Lighter colors with a hint of brown will last longer when exposed to direct sunlight.
• Storm doors can act as a greenhouse. Trapping heat and causing premature paint failure. Try to leave the top storm door window cracked open to ventilate this heat.
• 100% Acrylic paints will out perform traditional oil base paints when used on a steel door. Top quality exterior acrylic house paint is more resistant to the effects of sunlight.
• Seal the kick plate with a small bead of caulk before installation. This will act as a gasket and keep moisture from collecting behind the kick plate. The moisture will cause the paint to fail and rusting of the steel.