It is a mistake by some amateurs to use a pigmented finish which hides the effect of the stain.
Clear coat front door.
Buy two quarts of marine varnish one gloss and the other the sheen of your choice.
Tack it down with a rag soaked with paint thinner and a little varnish to make a tack cloth.
Then we flipped the door over and i repeated the process.
The most common kind of finish used on fiberglass doors is a topcoat known as clear coat.
Depending upon exposure you are good for another two to twenty years.
Clean the door and coat it with sikkens and a foam brush and wait for it to dry.
The combination has worked amazingly well for me on a west facing exterior oak door that looks as good today as it did after refinishing 7 8 years ago.
Previous varnish only finishes only lasted 2 3 years.
Sand your door lightly with 220 sand paper.
Take a bristle or preferable an ox hair brush and brush the varnish on brushing in one direction going from dry to wet.
Once the primer has dried on the front of the door flip the door over to prime the back.
Applying the clear coat took about 45 mins and we waited 2 hours for it to dry.
My front door a fiberglass prefinished door red mahagony color has the clear coat peeling from it.
Client has a new hickory door and jamb.
Brush on a single coat of primer with a wide paint brush covering the front and all side edges of the door primer prevents the door from absorbing moisture and helps smooth out its texture.
Going to go paint on the jamb so i m off the hook there but the door itself is supposed to be finished with a clear finish.
Clear coat ext door extreme sun so i should have turned this job away from the get go but i m committed and need to get it behind me.
This is a translucent finish which means that the staining of the door and any wood grain effect this brings out can be seen through the layers of finish.
With the clear coat the wood became much richer and glossier.
The best clear finish for an exterior door is 3 coats of clear epoxy followed with 2 3 coats of spar varnish.
I plan to scrape as much off as i can and then probably sand synthetic wool pads the rest off.
The other option is wood boat bright work and use spar varnish but realize boat coatings are made to be removed and renewed periodically so the same will happen to your door.