In my opinion spar varnish will give you the best clear coat protection against water.
Best exterior door finish.
From the original questioner.
Pettit marine paint s captain s varnish and epifanes wood finish matte.
An epoxy sealer with an exterior varnish topcoat is the most durable outdoor finish and can last for many many years.
For a natural look penetrating oil finishes might be your best bet.
Exterior paints are sold in flat matte eggshell satin semi gloss and gloss sheens in order of the lowest to the highest.
Water repellent preservatives wrps are a great choice on wood decks.
Whether it s a marine grade spar varnish or otherwise a film forming finish such as varnish only truly seals the wood when the film is intact.
Their popularity and effectiveness for finishing the bright work on boats makes them the best choice for protecting exterior wooden doors that are exposed to harsh weather elements year round.
A storm door would also be a big help in protecting the door form the elements.
An exterior oil finish is definitely the simplest quickest way to treat an outdoor project.
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.
Water repellents and water repellent preservatives.
Pettit marine paint s captain s varnish and epifanes wood finish matte.
Teak oil tung oil and tung oil finishes.
The same goes for exterior trim.
High quality formulations have finely ground pigments that block uv rays while allowing the grain to show.
My go to finish system for exterior doors is a combination of two products.
Prior to applying new finish scrub the surface with a cleaner containing an oxidizing agent such as bleach.
When it comes to painting your front door there are a million colors to choose from but only one real option for the finish.
Previous varnish only finishes only lasted 2 3 years.
They shed water for a year or so before requiring reapplication.
The best protection for an exterior door is opaque paint all clear finishes will need constant maintenance.
It s got to be semigloss.
Go for a semi gloss finish which is as durable as it is attractive.
Their popularity and effectiveness for finishing the bright work on boats makes them the best choice for protecting exterior wooden doors that are exposed to harsh weather elements year round.
The best clear finish for an exterior door is 3 coats of clear epoxy followed with 2 3 coats of spar varnish.
As soon as it begins to crack or peel it s only going to get worse.