Here's how to make your steel door look like wood!
Clean & Apply Base Coat
First, use 0000 steel wool to make sure the surface is suitable for paint adhesion. Use mineral spirits or paint thinner to wipe the door clean (or wash with a brush). Then wait for the door to dry. Tape paper over any glass in the door.
If you're using a lighter stain, apply a top coat of latex paint with a yellow or brown tone with an airbrush. This will make the stain appear more natural.
Apply Grain Stain
If your door has grained impressions, just apply the stain with a brush. If it doesn't have impressions, use a woodgrain tool to apply the first stain, making impressions as you go. Start with the inside panels, then work your way out. If any paint piles up in corners, use a brush to feather it out.
Add Tone Stain
Once your grain stain is finished and dry, use a brush to apply the second coat. The more stain you use, the less the grain will show and vice versa. Use a brush to feather out any stain build-up. Then lightly wipe down the stain with a terrycloth to have the stain level more uniform with the rest of the door. Wait 24 hours between additional coats.
Seal it up
When the stain is completely dry (24-48 hours after final coat), apply a finishing coat of outdoor water-based polyurethane. When it dries, violia! Your brand new wood-looking door awaits you, adding desirable curb appeal.
Project completion: About 2-3 days.