Epifanes for spar varnish. Be aware that several coats are required for optimum protection.

Another option is to paint the doors---with clear paint. Ultra deep tint base or #4 tint base(#5 for Olympic brand) will dry clear as long as no colorants are added.

Benjamin Moore has Urethane Alkyd Enamel exterior oil-base paint. The uncolored "neutral tint base" dries totally clear. This stuff is reasonably priced, and still available in California, where it is very hard to find oil based paints due to the VOC regulations.

Ben Moore also carries Fine Paints of Europe Hollandlac, which is just about the highest quality oil based paint in the world, definitely the most expensive paint in the store. The FPE Hollandlac Transparent Base is exactly what it says: transparent.

After cleaning, sanding, cleaning, and prepping the old wood, thin down the first coat with 25-35% mineral spirits. This will help it absorb into the pores of the wood. The next coat(s) may be applied straight out of the can. Be sure to allow proper dry time. Oil based coatings may not be recoated in the same day.

Thank you for the information. I talked to Benjamin Moore this morning and the only thing they suggested was SPAR Varnish which is what I've been using.

If I use this Hollandlac paint, can I stain the doors first? If so, do I still thin down the clear paint?

I would only add,the door's interior finish plays a role in exterior finish's performance. Your door is an extreme test of finish. Humidity is pulled through the doors from inside the home where it causes rapid deterioration of adheision. A good finish on inside of door will slow but not eleminate moisture migration. Most of the other exterior painted surfaces on your home have house wrap/moisture bariar plus ventilation between inside and outside.
I am an admirer of natural wood and detest fake wood floors,furniture and cabinets. Were I needing wood grain appearance on a new home enterance door, I would bite my tounge . and use fiberglass instead.

"I talked to Benjamin Moore this morning and the only thing they suggested was SPAR Varnish which is what I've been using."

That's because the people who sell paint and coatings are not the same ones who use them. Their goal is to sell a product as it is marketed, especially if the product carries an annual service contract. That's exactly what exterior wood coatings are selling you: an annual maintenance contract.

The point we're trying to make is that old school, experienced carpenters and painters are subject matter experts, not the people who sell the paint. We're telling you that, in our experience, the clear or neutral tint base of an exterior oil paint is the most durable clear wood finish you can find. To get the right stuff, you have to know what you're looking for, and walk up to the paint counter and tell them what to give you. You can't ask for advice, or you will get the same old scripted sales pitch that will inevitably steer you toward the products that carry an annual maintenance contract.

"If I use this Hollandlac paint, can I stain the doors first? If so, do I still thin down the clear paint?"

Yes. Stain the doors with an oil based stain and allow proper dry time. Still thin down the first coat of paint, or even mix the stain and paint 50-50 for the first coat. You'll definitely want to experiment on some scraps of mahogany with the staining. Sometimes mixing the stain and topcoat 50-50 for the first coat will give a more even color, with less blotching.

Please don't misunderstand. I called early this morning and asked for #4 or #5 Ultra Deep Tint Base which was the only thing posted at the time. They didn't know what I was talking about and asked what I was trying to do.

I plan on going over there now and asking for Hollandlac paint. I don't mind paying for the best I can get. I'm tired of wasting $60 a gallon and a lot of time and work every year redoing the doors.

Thank you so much for your help. It is very much appreciated.

Sandy

The manager of the Sherwin Williams store I have used for 20 years had no idea Ultra Deep tint base dried clear. He called two other folks and they also did not know.

Shoulda taken a picture of the expression on his face when he painted a test strip and it dried clear.

And the fella at a home improvement store said there was no way paint tint base could dry clear.

Yep, the paint store employee's job is to sell paint,not tell you things for free that will reduce demand. If you ask about applying interior latex on exterior surfaces,they will tell you the result is disaster. High quility interior latex will out perform low quility exterior which makes it a viable option in many cases. Not that that information relates to your doors but rather to the information gleaned from retail counter help.

Funny.
I've since used this stuff on my own exterior mahogany doors and so far, so good. But they're just going into the 2nd season.

I've also just used this base on some antique doors I've stripped (Yeah! Citristrip!) to gorgeous bare wood. I wanted the raw wood look and this paint base gives a completely flat finish. Goes on white like the others dries nonexistent. Anyway, these will get a lot of southern sun, so we'll see on these, too.

Good luck with your doors!

CEFreeman, which paint did you use? I was planning on the Hollandlac.

Hey! I'm sorry I didn't get back to you.. Didn't see the follow-up.

I walked into Home Depot and bought Behr, Flat exterior, Latex Dark Base. The only input I allowed from the sales child was to ask what base she'd use if she were tinting me a black or navy blue paint.

I've now put this on 4 interior doors I've stripped, in addition to my front mahogany doors and sidelites. Love the stuff!

I chose flat because it dries so flat and clear the wood doesn't look like it has finish on it. I have been going for a raw food effect. I'm sure if you chose some type of gloss or satin thing, you'd have some shine even with the base.

I picked up a can of Olympic exterior, flat dark base at the reuse center. I think this is great. Given the fact it's exterior, my interior stuff should be protected for .. generations! Yes! Generations, I say! :)

How's it coming for you?

One product I've done some testing on is Le Tonkinois. It's not your usual varnish but it's highly regarded in the wooden boat world.

I haven't tried it on outdoor work yet but I did experiment by putting some on a pair of wooden sunglasses then having someone wear it for daily jogging. Last I heard, it was holding up fine after a couple months.

Sun and sweat are hard on wood finishes so that's a good test. I've also had a sample survive car storage for over a month.