Does anyone have a recommended clear finishing system for custom built exterior oak doors to be installed in the Midwest? The doors are to replace existing doors on a historic building, and they have very little protection from weathering (water and ultravoilet) other than the fact that they are somewhat recessed in a thick masonry exterior wall.
spar varnish and remind the owner that it has to be redone every couple of years
Sounds like my front door in Utah. I asked the painter who stripped and redid the door last year to buy the varnish from West Marine (or equivalent) and not his local paint store. The next varnish coat is September’s project.
Amen, spar varnish. Very traditional material and look, and it holds up fairly well on the back door(custom built cypress)of our house. We’re due to reapply again this year or next, meaning we’ve redone it twice in fifteen plus years.
Anne didn’t mention, but make sure you specify multiple coats for the first application. I don’t exactly remember, but the first coat may have been thinned. Whatever, follow the recommendations, and you’ll be quite happy with it.
On topic: I have had several jobs that used Sikkens products - no complaints yet but I have not used them myself.
Off topic:
Remember that “spar varnish” is for the most part the manufacturer’s most weather resistant (clear wood finsh) product preferably made with a lots of Tung oil, UV resisters and a commercial (probably) polyurethane resin. One source on the web said they could’nt find reference to the term mush earlier that 1900.
look at the local paint store and you’ll see waterborne types (certainly not traditional) that might be fine.
Back in the OLD days the recipe varied and was mostly tung oil and other gums, resins, and rosins with oils, turpentine and dryers mixed up by the local craftsman doing the work
Any painters out there to fill in more gaps
Polyurethanes with UV inhibitors are not the same type of product as spar varnish, though some manufacturer’s will claim they last as long. (Note that in California, especially SCAQMD, you cannot use spar varnish in a field-applied application due to VOC content. There is no low-VOC product that will work as well, so you have to apply in a shop with the proper air-treatment equipment.)
Sun is the main killer of varnish and the underlying wood, so if the door is in direct sun it may need recoating as often as every other year. In shade, you will likely get longer life.
Ooops… I was (U.G.), above.
I agree John, I mis-spoke, I would not call them spar varnish either…but I have seen 2 differnt cans of “spar varnish” that were essentially polyurethane finishes. A rose by any other name… (but look under the leaves for product information)
I second Marc’s recommendation for Sikkens “Cetol.” I used it locally on a waterfornt home with south and west exposure. Used on windows and doors. Very good product with low sheen. Follow the recommended surface preparation and application to the letter. I will confirm I have quoted the correct Sikkens product.
Confirmed. Sikkens Cetol was the product used.
Marc:
I’ve heard the term “spar varnish” used for specific Marine varnishes as long as I can remember – and you do get the stuff at a marine supply store, not a paint store. I was specifying it by that name back in the late 1970’s. (maybe Idaho doesn’t have much use for spar varnish… but Ballard definitely does)
I agree with the Sikkens suggestion too – they make great products.
RE: John Bunzick’s comments
That’s funny - I recently purchased “Spar Varnish” at my local lumber yard (not Home Depot!)here in CA and "field applied it - I didn’t see any warnings anywhere.
For a university project I had a similar problem, and found no consistent definition for “spar varnish.” The following system worked well and was repairable. A significant consideration was that the University’s maintenance staff would do future refinishing. Urethanes can be difficult to partially refinish at damage. If possible, I would avoid wood where fully exposed to weather.
Finish System (This used to be TR-5): AWI catalyzed vinyl, premium; transparent, non-yellowing with UV inhibitors:
- System:
a. Stain.
b. Catalyzed vinyl sealer.
c. Sand (220 grit).
d Top Coats (2). - Apply catalyzed vinyl washcoat and filler as needed for uniform appearance.
- Gloss on 60-Degree Gloss Meter (ASTM D523): Satin, 30 50 gloss units.