I just want to start an on purpose thread on this topic to see who else has ideas. John was helpful for sure - does marine finish go over paint?
To be clear - this is what my old library looks like after being in Kansas weather for ten years. I’d like my new one to last longer. Anyone else have suggestions? I appreciate it!
I watched a youtube yesterday on adirondack chair finishing. They suggest a penetrating epoxy mixed with acetone from Total Boat.
I’m definitely not an expert, but TBH I think that looks pretty good for as long as it’s been. If this is the roof as it appears to me, perhaps finishing it like a real miniature roof with all the layers and flashing etc might be best.
A good exterior paint is a great place to start. Spar varnish is great, but would be more appropriate if you were trying to preserve the wood grain. That said, proper surface preparation is essential. A slight round-over on corners will help keep paint from cracking along the edge and allowing water penetration, as will tight well glued joinery. Paint has a life expectancy generally under the ten year threshold, reapplication every five years or so would be a good idea and keep it looking fresher.
A wide roofline and drip-edge flashing will help. Fixing any missing roof tiles is essential. In this vein, joinery and construction can be thought out so as to shed water away from joints thus reducing the chances that these problematic areas take on water. Also, water get’s places. It is unrelenting, any system that attempts a hermetic barrier against water will have compounded problems in the event of failure, I suggest having some drainage options from the interior in case the unexpected happens.
Fasteners. Use appropriate fasteners for exterior applications. Hot dipped galvanized for flashing and nailed joints, stainless for the joints if you want to get fancy.
And, @Sherry is right, your old library honestly looks pretty good for ten years!
edit: I put a piece of plywood in the hall outside the assembly room for you with your name on it.
Also, the epoxy is NOT UV-RESISTANT and must be overcoated with something like spar varnish, and said varnish will likely have to be reapplied far more often over epoxy than over other surfaces like wood.
Full disclosure, except in very specific situations I am not a fan of epoxy.
Edit: many of their epoxies are not UV resistant, some are.
Watch the video at totalboat.com. search penetrating epoxy. They also have the varnish specifically made for wooden boats to resist salt water and uv. Ive never tried it but it looked promising. The chair video is on youtube under jackman works. The epoxy\varnish looked great on his cedar adirondack chair. Its expensive though so paint may be the way to go.
Yeah, I was looking at the most economical offering they had.
Think about the structure of a piece of wood. It has a bunch of small tubes going up and down the trunk or along the branch. They bring stuff from the roots to the leaves and stuff from the leaves to the roots. The what and how much is not important to this discussion.
Think of the piece of wood, as a bunch of straws. Open end of the straw is where you cut across the log, or where you cross cut the board. The sides of the straws are where you rip cut a board or long along the length.
We think of this when we use terms as with the grain or against the grain. Also when we think of a tree that is cut down and the wood needs to dry, before we use it. Moisture from the wood will leave faster through the end grain, then through the side grain. So wood can be coated on the endgrain with something to plug the holes and slow down the moisture loss rate.
Now, turn that last one around. Don’t think of moisture loss as in drying the wood, think of moisture gain when the finished product gains moisture.
Plywood is made of several layers of thinner wood. These layers are crossed. That means there is end grain on all cuts of the plywood.
To make the project last longer, you can change your construction method. You can increase your maintenance efforts.
Construction Alternatives:
Use plywood:
Found pieces or purchase new plywood rated for exterior use.
Consider adding an edge band of wood or veneer to cover the ends of the straws.
Use an engineered wood products
Look at deck material
Perhaps look at Corian Counter top material.
Use a natural rot resistact wood
Cypress, and a few others from the US
Foreign Wood:
Teak is used on many ships and boats. The main decks of US Navy ships are teak. (I just purchased a small piece of the track from the USS New Jersey. 80 years old and 2nd reducing.)
Ipe: A south american hardwood that is imported and widely available, for decks etc. It is hard to work with, so you will be drilling pilot holes for nails, and using special saw blades to cut it.
Other types
Use commonly available US woods and adapt construction techniques. Talk to Doug, Aaron or others that are more familiar with these.
Increase maintenance.
Reapply the marine varnish annually.
Every 3 -5 years, remove paint and varnish, to bare wood. Then paint and varnish again.
General + / - : Longer life means spending more $ and time on initial materials and build. More $ and time on maintaining the project. Somewhere between the extremes on both side is a happy medium for you.
Different approach. Build from metal. Powder coat pieces and then assemble.
John
Go Right Ahead! How would you redesign a Happiness Box, using standard lunber and traditional joinery?
I have polyurethane, I’m thinking about using that over paint over primer over plywood. And also maybe just not worrying so much about it - making sure it gets a nice new coat of paint every few years. Or maybe I’ll want to rebuild it AGAIN in ten years, who knows?
