Outdoor finishes/ deck finishes/ boat finishes

[Popeye]

I'm redoing some upholstered seats in Dad's boat, dumping all the padding and coverings. I'm replacing all that with white oak slats which I'll toss stadium cushions or boat cushions on for use.
Figured from the start that I'd finish them with spar varnish but a friend asked why not deck sealer? Something like Thompson's or the like. And now I don't know. Any ideas on this? What been your favorite outdoor finish? Thanks, Pat

[movnup]

Hey Pat,

Something I actually know a lot about for once ..... As for the boat it depends on if it hits salt water or not but the main "boater finish" for brightwork is spar varnish in an oil base. This will yellow a tad with time and you need minumim of three coats, preferably five or six as it will hold up better to actual use or if it is in salt water. I have a lot of teak on my ski boat and for that I use a product call "Teak-A" that is a two part sytem for cleaning / bleaching and then teak oil with three of four coats. Usually that lasts about half a season in the great northwest and then one or two quick coats with a rag mid-term and it looks great. Both will work great under any conditions but I just like the oil look better than the varnish ... they both dry very hard and is the right tool for the job.

Deck cleaner and sealers are a different game completely. Whatever you do stay as far away from Thompsons or Behr deck products as you can as THEY SUCK as to longevity, overall finished looks, and trying to get it off again after you realized they sucked so badly e.g belt sander and ROS !!!. I have three decks on my house and I use products from a paint store that is a true deck cleaner as well as an oil based clear coat that will last a full two years looking great. If interested I could get the brand names for you .....

[gsmittle]

I just finished a deck, so I'm real interested.....

g.

[cabinetman]

Harsh or extreme outdoor exposure I would stay away from a film finish like a spar varnish. I know the stuff you've heard, but I've been there and done that. I've done a lot of Teak work and general woodworking for outdoor use, and I stick to a pure oil finish. I like Tung oil. Some brands of Teak oil, without any varnishes are good too. General Finishes makes a good oil finish called "Outdoor Oil", basically linseed oil. Oil finishes that contain varnishes may be called a "Danish Oil", are not a pure oil, and contain some varnish resin. For a pure oil finish it must say "pure oil", or 100% oil.

Here's the thing about spar varnishes. After some time, spar's have to be sanded and redone. That is a PITA. With an oil finish, maybe some light clean up or sanding, then re oil, is the way to go. Besides, you get the real look and feel of the wood in its "natural" state, so-to-speak. You can achieve a nice sheen with just the oil finish or wax can be applied.

[Popeye]

Hmmm, each of these chairs will have 10 oak slats, the idea of sanding them down every couple of years has no appeal at all. Would be easier to just remake them Looks like oil may be the way to go. Any brand names Mike? Think teak oil would work on the oak Movnup? Thanks Pat

[cabinetman]

Any brand names Mike? Think teak oil would work on the oak Movnup? Thanks Pat

Pat - There are many oils for sale that claim to be specie specific. I'm including this site as an example of what marketing does to the products available to us. White Oak is a closed grain specie that works outside very well. I wouldn't sand it much smoother than 180x, to get the grain to open up some. After you get a few coats, dress it with 220x. As for oils, like I said I prefer just a plain pure oil, like tung or linseed. Linseed will darken. The application schedule could include thinning the first coat or two with MS and letting it soak in for a bit and then wipe off the excess, so there won't be a puddling of oil in any one place. The trick to getting good saturation is to let it do its thing. Then use full strength and let sit until it doesn't soak in and then wipe off. Repeat the process initially until you get some surface sheen when dry.

As for the UV inhibitors that are added to some brands, they may help or not. I can tell you that the oil finishes were used waaaay before the UV revolution.

[movnup]

I used teak oil becuase I have teak .... you would probably have to run a test but I like the way it applies / looks / wears and use Mike's idea of linseed as the alternative or vice-a-versa. As an FYI, it dries to a medium brown semi-gloss (looks better on my boat) which is why almost all yachter's use spar varnish instead as it has a very light tint, almost a pale yellow when dry (to match their boat and also it lasts two or three years v. a yearly job). Spar varnish hold's up to salt water much better than an oil too which we have a lot of out here..... I've used both but the sanding job between the slats on the swim deck was a PITA. You can't go wrong with oil and West Marine has a nice selection. Use Teak-A to clean and prep yearly and hand wipe on two or three coats of oil and it's good.

GS - I'll get the names off the cans tonight as to deck products that work well .....

EDIT: Wolmans 3 Year F & P (finish & preservative) for the deck boards, the cleaner was a mix that was boidegradable so it won't harm your landscaping ( i must of used it all up so I don't have a name)

[JR]

There have been some interesting comments re: oil v spar varnish.

I am currently sanding the UV Poly off a redwood bench, and putting a BLO finish on it. I built the bench three years ago and this is the second time I've refinished it.

Having said that, I have an article from FWW that defines a two-part outdoor finish that might be good for this application. First is an epoxy "primer", followed by spar varnish. They claim this techique makes refinishing less frequent and less difficult than otherwise.

YMMV

JR

[cabinetman]

I've done outdoor wood in both finishes (oil and film). What I've noticed is a failure of the film finish to maintain integrity with the changes in the wood. It's nearly impossible to seal the wood completely and air and moisture vapors will enter and exit the wood, in patterns of regularity. If the wood was completely sealed, like dipped, it would be even worse. This activity has its effects on a film finish. It won't react as the wood does, and becomes crystallized so-to-speak. It turns a hazy white and becomes brittle and begins to peel away from the wood.

[Popeye]

Well, started looking through the finishing cabinet and lo and behold I found a bottle of "teak oil" I bought when I had the Grady White and had real teak WW. Decided to give it a try. First coat soaked in pretty quick, put a second coat on and I'll let that set overnight and see how it goes. I figure a min. of three coats. Looks great on the white oak. Thanks folks.... Pat