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START TO
FINISH: THE ENDURANCE TEST
By Michael Dresdner
This is an excerpt from an article in the June, 2000 issue of Woodworker's
Journal.
 Picking the "right"
finish for your most recent woodworking triumph may seem like a daunting
task, given the confusing array of choices. To make the correct choice,
start out by answering three primary questions before you begin:
1. How durable does the finish need to be;
2. What kind of appearance do I want; and
3. What's the best application for me?
Durability
Durability is the first thing you should determine. Ask yourself,
"what must this finish endure." An art turning can get by with
nothing more than a coat of oil. A kitchen table or countertop, which
needs to endure hot coffeepots, scratches, stains, and even chemicals
and strong cleansers, will require something much more durable. Patio
and outdoor furniture will need a finish that can stand up to
temperature and humidity variances. Salad bowls and cutting boards need
a special "salad bowl" finish, which is specifically made for
objects which come into contact with food.
Durability is also affected by how thickly a finish is applied. A
very thin finish regardless of the type, will not protect as well as a
thicker application of the same finish.
Appearance
Staining, of course, changes the color of the wood, but clear finishes
will also alter the appearance of the wood. Most waterborne lacquers and
polyurethanes are completely clear to slightly blue-gray. They will add
almost no color to white woods such as maple, holly, and spruce. Shellac
and lacquer will add warmth and color to the wood. Oils (including
Danish Oil, Tung Oil, and oil-based poyurethanes) generally add the
greatest amount of amber tones to wood, especially when several coats
are applied.
With figured woods, such as curly or bird's eye maple, you can
actually use the finish to intensify the figure, or "pop the
grain," even without staining. One of the best "grain
poppers" around is boiled linseed oil but shellac, lacquer, and
most oil-based varnishes will also do the trick.
By adding one or two coats of shellac to a piece of figured wood, you
can achieve a stunning effect called "chatoyance," from the
French meaning "like a cat's eye." If you've ever seen the
semi-precious stone Tiger-Eye, you'll notice that as you change your
viewing angle, the light and dark bands of color change places; this is
chatoyance.
 Application
Most finishes can be applied in a variety of ways. Shellac, for
instance, can be wiped on, brushed on, or sprayed on. The same is true
of Danish Oil, varnish, and most waterbornes. Some finishes, however,
lend themselves more to one application style or another, and others are
formulated for a particular application method.
Waxes and gel finished are specifically designed for wipe-on
application. Though nearly every varnish or polyurethane can be wiped on
instead of brushed on, some are designed for easy wiping and thin
application. This will usually be stated on the can.
Certain lacquers and conversion varnishes are designed for spraying
and will dry too fast if applied with a brush or rag.
To help you choose the right finish using Dresdner's
"Appearance, Durability and Application" approach, we've made
a comparison guide of all our carefully selected finishing products. See
our Finishing Comparison Guide
for a complete chart of products.
Michael Dresdner is a nationally known finishing expert and
author. This article originally appeared in Woodworker's Journal
May/June 2000 issue. For a free trial issue, Click
Here.
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