help with wood selection

[Ted Daigle]

Okay, I'm a little confused here (like that's anything new). My wife came to me with plans for a bench that she would like to have on our balcony. One problem: the plans were for an indoor bench and called for birch plywood finished with paint. My wife wants the bench outside (although it is semi-protected from the elements on the balcony) and wants it stained. To make it with cedar or some other type of outside wood would take a million glue-us. Using plywood would be simpler.

Can I just use oak ply, stain it and use plenty of semi-gloss marine type poly? To me it seems like the same theory as having an exterior wood door. Anyone see any red flags with this plan?

[Bob Noles]

Ted,

Go with solid wood for outdoor use. I have never had much luck with ply of any kind holding up in the elements no matter how well I finished it.

Good luck with the decision and keep us posted on the progress with some pictures.

[Brian Hale]

I'd go with soild wood (cedar, WO, Ipe etc.) as a first choice. You can also get marine grade plywood which is very water resistant and would lst a long long time.

The problem with regular plywood is the layers seperating over time from moisture. If you can seal the edges well (solid wood edging) you'll add a lot of life to the project.

Brian

[scott spencer]

I'll echo the solid wood suggestion. You're likely to be more pleased in the end. ...white oak, teak, cedar, cypress would do well to a name a few.

[Doug Shepard]

The problem with the plywood is the glue used to hold the plies together. Plywood with glue rated for outdoor use will have an "X" after the facing veneer grades - Ex. CDX which is the cruddy looking ply used for exterior house sheathing. I'm sure somebody makes it, but I've never personally run across oak plywood with exterior rated glue. Your options for finding ply rated for exterior use is likely to be limited to construction grade stuff which isn't going to look real good for furniture.
I'd stick with the solid wood suggestions.

[Steve Cox]

Your best bet for exterior ply will be BS-1088 rated marine mahogany. If I remember correctly it is designed to be submerged for 20yrs without delamination. Boat building suppliers or specialty (commercial) wood suppliers should have it. It'll be easier to work with than solid and extremely durable.

[tod evans]

baltic birch is also available with an exterior grade glue......02 tod

[Chris Barton]

Cypress without a doubt. I would not finish it though. That is unless you want to be refinishing it every 1-2 years thereafter. Cypress has long been used in boat building and is nearly rot-proof.

[Jim Becker]

Use materials suited for outdoors and consider something different than poly to finish it. Even so-called "marine" grade will need to be stripped and redone with more frequency than you'll enjoy. One finish option is to get oil-based exterior tint-base paint...it's clear and has the necessary UV additives. And paint is more durable than any varnish for this application.

[John Callahan]

In your neck of the woods there might be some cypress around, old growth if you can find it ............. should work pretty good.

[Barry O'Mahony]

Plywood is used externally all the time (e.g., house siding), when it is built with exterior glue, and painted. Paint actually provides alot of weather protection.

A clear finish isn't gonna offer as much protection as paint. "marine" or "spar" exterior poly has UV protection, and is more flexible (softer) than interior poly.

The best protection for exterior stuff is epoxy, covered with spar varnish for UV protection. This is how wooden boats are done. There was a FWW article on doing this for outdoor furniture a little while back.

[Greg Heppeard]

You should be able to find some old "Sinker Cypress" I think it has a lot more character than new. "Sinker" is old logs that have been dragged up from the river bottom then taken to the sawmill. Some of the logs could be 150 years old or more. There is also "Sinker Pine" but I think it would make better flooring.