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wrighthouse_gw

restoring finish on exterior ceiling

wrighthouse
16 years ago

I need some advice on how to restore the beams and planking that extends from an interior ceiling outside to cover a deck. (There are pictures on the link at the bottom of the page.)

The condition of the interior wood is fine, but the exterior has gotten weathered (25+ years of neglect by previous owners.) It is sheltered from sun and rain but there may be some moisture damage from before they replaced the roof.

How should we go about the restoration? We were planning to sand off the remains of the old polyurethane and then stain to match the interior. Can we use an interior oil-based stain and then cover it with something like "spar" polyurethane? Are there better products out there? What do you recommend?

Here is a link that might be useful: pictures

Comments (6)

  • randy427
    16 years ago

    I've found deck stain with Tung Oil to give good results (one-step), though I have not gone for a glossy finish. Superdeck is the brand name I've used.

  • kmealy
    16 years ago

    Something like a "spar" polyurethane, particularly one that you find a big box store, is probably not the best choice. You might get better results being sheltered, but the normal life of these in an exposed environment is measured in weeks. See the link below.

    But definitely clean and scrape off flaking finish before you start. If you wipe down with mineral spirits, you will get a good preview of what it will look like with a coat of finish on it.

    Here is a link that might be useful: some options

  • wrighthouse
    Original Author
    16 years ago

    Thanks for the suggestions. I'm not necessarily looking for a gloss finish. The interior has a nice matte finish. I've gone for oil based stains on the other exterior wood (decks, cedar siding) with good results and love the look tung oil gives to my exterior furniture. The reason I was looking to use a polyurethane on this project is because the carpenter bees have discovered the wood on this exterior ceiling.

  • kmealy
    16 years ago

    Be aware there is 100% Tung oil and there are myriad "Tung Oil Finishes" The latter are usually wiping varnishes (varnishes thinned with mineral spirits) or linseed oil - varnish blends. Neither of these contain any tung oil at all.

    If the can says anything about mineral spirits or petroleum distillates, the only thing tung oil about it is on the label. You may also see "oil-modified resins" of some sort. This is just double-speak for varnish.

  • wrighthouse
    Original Author
    16 years ago

    I'm very limited in where I can shop locally. Lowes sells something called Formby's "Traditional" Tung Oil Finish and only by the pint. The back of the can says it is a blend of Tung oil and other penetrating oils. That doesn't sound like 100% to me. Can you suggest any sources?

  • kmealy
    16 years ago

    Pure tung oil has more mystique than value. It requires many coats, with sufficient drying time in between and is prone to turning white. Nor is it a very effective finish.

    Formby's "Tung Oil Finish" is simply a varnish that is thinned about 50-50 with mineral spirits to make a wiping consistency. You could use any varnish you want, buy an equal amount of mineral spirits, stir them together and have something just as good or better.

    Here is a link that might be useful: Oil finishes