Interior or exterior?

The first coat of any finish seals the wood. It is not necessary to use a separate product. In fact, there are several disadvantages to using a "sanding sealer" -- it will both weaken the finish and reduce the water resistance.

Sorry, should have mentioned that - exterior door. Relatively well sheltered but exterior nevertheless. I'm not sure what a "sanding sealer" is - I went to the paint store tonight and they recommended Minwax stain with a spar varnish as a finish coat. Thoughts?

If the "spar varnish" is Helmsman,, run the other way. It's a terrible choice as it has little UV resistance. See the link for an article on how well it fared. A quality spar varnish will not be found at most paint stores, certainly not the big boxes, but at a nautical supply house. It will run about $50 a quart. Even then, expect to refresh it every couple of years.

Sanding sealers are typically have stearates (metallic soaps) that make them powder up easily. The problem is, if you hit them with anything (think something carried in the door), it can turn white and no good way to remove the white mark without stripping and refinishing. And like I said, it also makes the finish less water resistant. Further, not all finishes adhere well to all sanding sealers. The result is flaking and peeling. While they (might!) make sense in production environment for furniture, they are really an unneeded expense for the DIY.

I suggest using the finish in the link below. Go to a paint store (even Lowe's or Home Depot) and get some exterior, oil-based, trim paint in deep base (usually labeled #4 or #5) and do not allow the paint OAG to add any pigment. Ignore their statements that it will not work or they can't sell it that way. Sneak in the cage and head to to the cashier while they are mixing and shaking some paint if you have to. Lie to them and tell them you are going to add your own pigments (say UTC).

Here is a link that might be useful: Options and comments on

Kerry,

When Simpson said "stain and seal" I don't think they meant a sanding sealer. Those are designed to help even out stains on woods prone to blotching like pine but blotching is not generally a problem with oak. Instead they mean some kind of film finish like varnish.

I'm looking at a similar project myself and after quite a bit of research there seems to be as many opinions as to what is "best" as the people writing them. Some is a function of experience and personal preference and others seems to be what is just readily available. In the end, any finish is going to require maintenance and the more opaque the finish, the longer it is going to last. But you didn't spend the money on an oak door just to paint it.

Bobsmyuncle's suggestion of using a deep tint paint base is new to me (I was quite surprised to hear that it dries clear) and may be an excellent choice as a top coat. I've also read some good reviews of a varnish from Epifanes. It's marketing to the boating world and while it may be hard to find, West Marine does carry it. It is expensive, $36 per quart.

The current issue of Fine Woodworking #205 has a review of outdoor finishes. I haven't read it yet but you should be able to find a copy a woodworking stores, home centers, and possibly your public library.

Whatever you do, just remember to finish all six sides of your door.

Here is a source for marine varnishes.