I want to re-stain my front door. The top half looks fine because it doesn’t get the sun like the bottom half. Do I need to strip the stain off my outside door completely even though the bottom half is the only part that needs to be stained due to sun exposure?
You happen to have touched on one of our company's specialties. Short answer is Yes, you need to strip the entire door to be assured to achieve a single coloring and finish to the door.
Several manufactures make strippers, what we use is a water rinseable stripper. We are able to strip in place as we have the proper equipment. I would not suggest the homeowner try this. Therefore you will probably need to strip both sides of the door. However you choose to strip, talk to a local paint dealer for the best products.
After you have stripped the door, allow to dry over night. Sand and stain the door. This may be done with the door in place and is actually easier that way.
Allow to dry over night and varnish. There are several schools of thought on this and I tend to go against the grain. (pun intended) We will finish with 3 coats of Minwax Semigloss of Pittsburg Paints semigloss polyurethane varnish. The label and the dealer will tell you this is an interior varnish. It is and the reason I use it is because the exterior varnishes do not service any better or longer in my experience. Down side to the exterior varnish is they darken CONSIDERABLY over a short amount of time.
The reason we are able to use the aforementioned products, is we will only strip a door if the homeowner agrees to a yearly deal where we apply at least one coat of varnish. We will usually apply two each year sanding lightly before each coat.