fundamentals continued
Of all the domestic woods I know—and I know a lot—black locust resists the ravages of fungi and
moisture the best. It is the best choice for furniture parts that are in direct contact with the soil.
As it never has more than three years’ worth of sapwood, there is very little waste. The downside is
that it is tough to work. Although it grows just about everywhere, it can be difficult to find because
it is only just now appearing on the fringes of the commercial
radar. However, with a bit of leg work (try an Internet
search) you should be able to find it in
your area.Building durable outdoor furniture isn’t only
about picking the right wood. It’s just as
important to build smart. That’s because it
expands and contracts far more than indoor
furniture does.
Start by creating surfaces that naturally
shed water, such as angled seats. Keep parts
narrow and give them enough space to expand
and contract. On a seat, for example, six
narrow slats are better than four wider ones.
Leave end grain exposed where possible; that
allows the wood to dry more easily, making
it more difficult for mold and fungi to start
growing.
When it comes to joinery, simpler is better.
Mortise-and-tenon joinery, bridle joints, and lap
joints are good choices. Use a waterproof glue,
like Titebond III, to hold the joints together,
and reinforce them with a peg or two. Or you
can forgo traditional joinery altogether and use
mechanical fasteners such as bolts and screws
made from stainless-steel or brass. Ceramic-
coated decking screws work, too.
—Matt Kenney is a senior editor.Latin name:
Robinia pseudoacacia
Average price
per bd. ft.: $3–$
Specific gravity: 0.
Percent shrinkage:
Tangential: 7.
Radial: 4.
T/R ratio: 1.Average price
per bd. ft.: $3–$
Specific gravity: 0.
Percent shrinkage:
Tangential: 7.
Radial: 4.
T/R ratio: 1.moisture the best. It is the best choice for furniture parts that are in direct contact with the soil.
As it never has more than three years’ worth of sapwood, there is very little waste. The downside is
that it is tough to work. Although it grows just about everywhere, it can be difficult to find because
it is only just now appearing on the fringes of the commercial
radar. However, with a bit of leg work (try an Internet
search) you should be able to find it in
your area.
$3–$
0.Tangential: 7.
Radial: 4.
T/R ratio: 1.Legs built to last. Because the end grain of
its slab legs is in direct contact with the soil,
Jennifer Wickham made this bench from black
locust. No other domestic wood is better at
handling the stress of constant exposure to
dirt, moisture, and fungi.How to build furniture that survives outside
SHED WATER NATURALLY KEEP PARTS
NARROWKEEP JOINERY SIMPLE
Reinforce joints
with pegs.Water sheds off
the curvature of
the arms. Use more
smaller seat
slats vs.
larger ones.Keep end grain
off the ground
if possible.Bridle
joints and
lap jointsKeep end grain
exposed to dry
more easily.Mortise-
and-tenon
joineryBlack locust
12 FINE WOODWORKING Photo, top right: Jessica Wickham; drawings: John Hartman
FWSIP27OF-FU.indd 12 2/4/13 11:49 AM