Replies

1. 
   DonCanDo | Sep 24, 2008 01:03pm | #1

   If it gets direct sun, plan on maintenance regardless which clear finish you choose.  If you can see through the finish, so can the sun's rays.

   Some products work better than others.  I used marine spar varnish on a door and 2 years later, it still looked pretty good.

   Take a look at this thread for some additional product recommendations:

   http://forums.taunton.com/tp-breaktime/messages?msg=95097.1

2. 
   jocobe | Sep 24, 2008 04:08pm | #2

   On the front and back doors of my home I've used this for 20 years:

   http://deksolje.com/

   There's a #1 and a #2 finish. I prefer the look and low maintenance of the #1 finish. I just put another few coats on my side lite panels last weekend. I take the door off the hinges and lay across sawhorses and continually coat until it has finished absorbing. Flip it over and do the other side.

   I really dislike the look and constant maintenance of urethane type finishes.

   My doors are mahogany, so I'm not sure how fir would do....call them up!

   .

   
   

   ---

   Edited 9/24/2008 9:10 am ET by jocobe

3. 
   frenchy | Sep 24, 2008 04:20pm | #3

   lowtech

     paint!

     Sorry but that's the longest lasting lowest maintinace finish there is..

      I used the premium grade of marine spar varnish on my exterior wood and it lastest less than 4 years..  that;'s with three coats of carefully applied Top grade marine spar varnish. (epiphanes) 

    Lower cost marine spar varnishes  won't last that long!

4. 
   Gene_Davis | Sep 24, 2008 04:46pm | #4

   I was with ThermaTru doors, and had responsibility for product development.  The testing laboratories were all under my charge.

   ThermaTru makes steel and fiberglass doors, and the fiberglass product lines can be stained to look like wood.  ThermaTru markets and sells a kit for staining and clearcoating their fiberglass doors, and the products used in those kits underwent a quite comprehensive testing program.

   ThermaTru tested every kind of exterior clearcoat finish in the marketplace, not only on their textured fiberglass substrates, but on all the commonly used exterior woods used for entry doors.  Those species were doug fir, cherry, white pine, white oak, red oak, mahogany, spanish cedar, and more.

   After testing all the name brand clearcoat coatings available to painting professionals and also to DIYers, and those finishes included spar varnishes, marine coatings, exterior polyurethanes, etc., ThermaTru finally rejected all of them as insufficient, and embarked on a huge R&D program to develop their own.  The end result is the highly specialized waterborne clearcoat available in the stain kits that they market today.

   That stain kit is available from any lumberyard or lumber dealer or bigbox store that sells ThermaTru doors.  I recommend you buy a kit, put the stain aside, and use the clearcoat on your door.

   If you don't want to do that, try this stuff, available from Woodworkers Supply (http://www.woodworker.com)  It is a moisture-curing urethane, and short of the ThermaTru coating, it is the most durable stuff I know for exterior use in a tough exposure like yours.

   View Image

    

   View Image

   "A stripe is just as real as a dadgummed flower."

   Gene Davis        1920-1985

5. 
   BryanSayer | Sep 24, 2008 04:46pm | #5

   There are two part epoxy finishes available. You will want to send the door out to a shop that does these, as they are not DIY friendly.

   The next best choice is a nitrocellulose lacquer, like the one from Sherwin-Williams.

6. 
   sungod | Sep 24, 2008 05:50pm | #6

   Provide as much shade as possible. Add eaves, roof, porch and/or trees.