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.
Clear coat for exterior wood door.
Protecting the finish and wood from uv light choose a high quality long lasting clear finish for your beautiful exterior hardwood doors.
At the surface of the wood uv breaks down the glue called lignin that holds the wood fibers together.
This can cause problems if you apply the wrong type of polyurethane.
Through a process called photo degradation ultra violet uv radiation damages the wood and the finish.
Polyurethane wood finishes are synthetic coatings that prove highly durable and water resistant making them the best clear coat for wood protection.
Homeowners often wish to show the beauty of quality wood on exterior doors and trim with a clear finish.
Clean the door and coat it with sikkens and a foam brush and wait for it to dry.
Of the three clear exterior finishes exterior oil is by far the simplest finish to apply.
The film forming products both classic varnishes and modern urethanes are unmatched in their ability to bring out the beauty and depth of a wood surface while guarding against wear and tear.
There are three basic clear finishes for outdoor furniture.
Polyurethane is the most durable of clear exterior finishes.
The finish will not hold up to the sun and weather requiring yet another refinish job.
Either by forming a hard film over wood or by penetrating it.
Clear finishes work in one of two ways.
Depending upon exposure you are good for another two to twenty years.