The quickest way to strip paint off of a door is to sand it. Chemical strippers are an effective way to strip paint, but paint stripper makes a mess, and you must allow the door to dry before you can stain or paint it again. There are several types of sanders available that you can use to remove the paint without ever using a chemical stripper. One of the most common sanders for this purpose is an orbital sander.
Use a variable speed drill to remove the screws in the door hinges on the door frame. Ask a helper to hold the door while you are removing the screws to keep it from falling.
Set up saw horses, preferably outside, to lay the door on. Remove the hinges, and doorknob. Place the screws, hinges and doorknob in a small bucket to keep all of the hardware together.
Attach a piece of hook and loop sandpaper to the orbital sander. Use the sander to strip the paint from all of the flat surfaces. Change sandpaper often. You should not have to struggle with a sander to strip the paint off of the door.
Sand recessed areas, on a raised panel door with 100-grit hand sandpaper. The head of an orbital sander will not fit into these areas. Sand a second time with 220-grit sandpaper. Repeat this step, and Step 3 on the opposite side of the door.
Sand the hinge and latch side of the door with the orbital sander. Use the 100-grit hook and loop sandpaper first, and sand a second time with 220-grit hook and loop sandpaper.
Look closely at the surface of the door for swirl marks. Paint can build up on orbital sandpaper and cause swirl marks. Use 220-grit hand sandpaper to remove swirl marks.
Sand only in the direction of the wood grain when using hand sandpaper.