Yet another "Help me finish my exterior door!" discussion

[Dan Mages]

I know there are other threads out there on finishing an exterior door. I want to verify that I have all of my ducks in a row before starting the project.

We installed a new Simpson fir Dutch door as part of our screen porch rebuild project. I want to give it a good coat of varnish. I have the following questions regarding the project.

1. Do I need to tape each of the nine lights?
2. I will give it a coat of sand sealer before the final coat. There seems to be carrying opinions on how long to let it dry before the next step
3. Even though it is a clear finish, should I give it a coat of oil or natural stain before the final coat?
4. Is spar varnish still the best way to go for a final coat? What is the current opinion on the best brand? Should I cut it before using?
5. How long should I let it dry before I can shut the door for the night? I will be doing this in the evening after the kids are in bed.
6. I will sand it with 220 and then 0000 steel woo after the first coat?
7. How many coats?
8. Any other steps that I have missed?

Thanks!

Dan

[Sam Layton]

Hi Dan,

I want to start out by saying that I am not a finishing expert by any means. That being said, I like and use General Finishes products.

I think you are over thinking the finishing of your door. I used General Finishes Exterior 450 on my front door. I used GF oil base stain to stain the door. Then I used GF Exterior 450 for the top coat, about 4 coats sprayed as I remember. If you use an oil base stain, you must allow it to dry completely before applying the water base top coat.

I just looked at GF's web page, and see that they have an exterior 450 primer. When I did mine they did not have a primer, and recommended just applying the stain, and top coat. My door has been finished for about a year and an half. It looks like I finished it yesterday.

Responding to your questions:

1. I think you must unless you want apply finish to the windows.
2. Depends on what type of finish you use. With GF's not necessary.
3. If you want to stain, you must stain the door prior to applying anything else. I don't like using water base stains, I like oil base stains, GF oil base stains.
4. I don't know anything about spar varnish. I like GF, and no, don't cut it.
5. I would not recommend finishing at night depending on how cold it is. There is a recommendation on the can regarding the lowest temp you should finish. I can't remember 60 deg I think
I recommend you start finishing in the morning. You can give it several coats in a day. The finish must be dry prior to closing. If you have to, put wax paper between the door and jamb.
Note: It is better to finish the door off the hinges. Make sure you finish both sides, and don't forget the top and bottom. Everything must be sealed.
6. Forget the steel wool. Don't use steel wool on water base finishes. Just sand between coats with 350 - 400 grit.
7. 4
8. Make sure you finish top and bottom.

I recommend that you call GF's and talk to them. They are very helpful.

Good luck on your door, Sam

[Scott Holmes]

I recommend finishing the door while it is laying flat. Cut a piece of plywood and fill the door frame for a couple of days.

I usually seal the top edge and bottom edge then attach a 1x6 to the top and bottom edges of the door; then you can span it on the edge of the 1x6 and access both sides of the door while it is laying flat supported by the 1x6's on sawhorses.

Easy to do, not so easy to explain without a picture... done properly the door could be laid on the floor and be about 2" off the floor; the 1x6 long edge will be touching the floor.

FYI - Polyurethane is highly susceptible to UV damage If you use a varnish don't use one with urethane resin in it. It will get chalky and fail very soon; 6 months or less in Houston.

[Steve Schoene]

Sanding sealer is a bad idea. If you are using a oil based finish there is very little to be gained from a first coat of oil. Between coats light sanding with 430 grit is a good idea. Steel Wool is not--steel shards can be trapped and rust down the road. Spar varnish is still a good choice. it will be pretty durable if not in direct sun on a porch. In sun, no clear finish will hold up very long, and paint in a light color would be the best choice. For spar varnish, follow label direction as to number of coats. DO NOT follow label instructions that say not to thin. All good marine spar varnishes require thinning. My top choice would be Epifanes Gloss. It will require thinning--start with 10%. Other good choices are Pettit Captain's and Interlux Schooner Plus. These too will need thinning, perhaps not as much as the Epifanes. Personally, I like to do doors laying flat, using a plywood substitute to keep out the critters.