Natural Exterior Wood finish - initial performance

[william sympson]

I mentioned an exterior wood finish recipe I used in a post on the deck i built; google FPLRN 046 and you'll get the link (Forest Products Laboratory Research Note 046). I did not use the stain portion of the recipe or the fungicide. I used 3 heavy paint brush coats on my deck floor (80 year old oak barn siding) and then wiped any excess off, though only a couple spots needing wiping down...several square feet could have used another coat but i'll get that next year. I also mixed up 5 gallons of the recipe with a stain to use on our yard fence - looks great. The fence only got one coat, so it doesn't bead water as well as the deck.

We finally got rain today, so I thought I'd post a pic of the deck floor to illustrate how the finish is working so far. Note that it is not slippery when wet at this time - the finish is actually a tad bit tacky when wet...at least on this oak. This finish is/will be my go-to for all my exterior wood.

Disclaimer: I don't own stock in any of the recipe component suppliers, no performance or warranty claims are made, and your results may vary!

R/
William

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[Julie Moriarty]

After trying many exterior stain products and being disappointed in them all, I ran across a product called Defy Extreme. Application requires two coats, wet on wet. Two years ago I applied it to new cedar on a gazebo roof I rebuilt. It still looks the same today as it did then. Last year I applied it to cedar T&G boards on the front of our house. It gets a lot of direct sunlight. Today it looks just as good as when new. After trying Behr, Thompson's, Olympic and Penofin, I'm sold on Defy. This is not to say FPLRN 046 isn't as good or even better. I've never tried it. But I'll keep it in mind if Defy ever let's me down.

[David Weaver]

What's the fungicide, penta? It sounds like the penta soak is proven, even if it's just a cold soak in a barrel.

[Mel Fulks]

I think Penta is off the market. For years it was the active ingredient in pre paint treatment used to dip millwork at point
of manufacture. The product stayed on the market without it ,kinda like beer without alcohol. Copper naphthalate can still
be bough and is quite effective, but best under paint since it colors the wood.

[David Weaver]

I am not that old, but I remember when I was a kid that (after reading the penta study, and my relatives fit the target of that study, farmers setting posts) any fencing made of rough lumber that was to be put up included a creosote dip. Black fencing was easier than white, and the creosote was a cure-all. I was painting a fence for a relative who was a loyal creosote dipper, and creosote went off the market, and we mixed what little he had left with diesel fuel and used motor oil. It improved the look of the fence, but I doubt it had the same staying power.

I guess everything that we do to preserve wood is ultimately going to be found to be detrimental if it stops rot without being a moisture barrier/membrane. If it stops biological processes, it's probably not very good for our biological processes, either.

[Mel Fulks]

David, the copper naphthalate can be found in some of the BORGS in the oddball toward the back of paint periphery. In this town some stores have it and others don't even though part of same chain. It is weaker than the solution sold by permit in quantity to contractors and its full of fed law use rules. It works.