The wood we know as poplar has many common names, such as tulip poplar, yellow poplar, tulipwood, yellow tulipwood, tulip tree, whitewood and canoewood. The “tulip” part of these names comes from the tulip-like flower the tree produces in the spring. Where the “poplar” part of these names comes from is a mystery, because the tree is not even a true poplar—it’s a member of the magnolia family. In fact, poplar is known as the “king of the Magnolias.” It’s also the tallest hardwood tree in North America.
Regardless of what it’s called, Liriodendron tulipifera Magnoliaceae produces very useful and versatile lumber. The tree grows fast, with a straight trunk and no branches near the ground. That translates to knot-free boards that are available in expansive widths and thicknesses. Poplar is economical, costing considerably less than other hardwoods such as maple and oak, and its finely textured lumber works well with both hand and power tools. These qualities make poplar suitable for many furniture and construction applications.
An ugly duckling
So why isn’t poplar popular with furniture makers? The
answer is simple: The wood is just plain homely. Its color
ranges from pale yellowish white to an odd shade of green,
and boards are often discolored by dark gray or purplish
streaks. To top it off, poplar doesn’t stain well with traditional
wood stains. In fact, it can get ugly really fast because it
blotches so easily. About the only time furniture makers use
poplar as a primary wood is when the piece is going to be
Poplar has too many desirable furniture-making qualities
to be limited to “paint-grade” service. Fortunately, by using
a special approach, it’s possible to make this ugly duckling
glow beautifully. This process will transform poplar’s odd
green color to any brown wood tone you like. However, dark
streaks will still show—they’ll need to be avoided or placed
strategically in the design and called “character.”
The key to giving poplar a rich, even stain color is to
control its horrible blotching tendencies. This requires
starting with a very effective stain controller (also called
wood conditioner or pre-stain sealer). The commercial stain
controllers I tested didn’t provide enough blotch resistance,
so I developed a simple recipe to make a controller with the
necessary strength. This recipe and the finishing steps that
follow work well on any wood that’s prone to blotching.
After applying the stain controller, use a two-step
coloring process for better control and color intensity. This
coloring method combines the benefits of both dye and
pigment stain. The dye provides a ground color as strong
and rich as needed, and the pigment ensures that the
color doesn’t fade and become dull over time. The dye and
pigment colors shown here are both a medium-dark “warm”
brown. They combine to create a rich chocolaty tone on both
the green heartwood and pale sapwood. Your color choices
may be different.
1. Prepare the surfaces by sanding to 180 grit. Be sure to
sand by hand after you power sand, to eliminate swirl marks.
Pay extra attention to the end grain.
2. To make the stain controller, mix one part General
Finishes Clear Gel Varnish with three parts paint thinner.
Apply the stain controller with a rag and allow it to soak
in (Photo 1). Be sure to saturate the wood, especially the
end grain. After a couple of minutes, but before the stain
controller starts to set up (5-10 minutes), use clean, dry rags
to remove any that has not soaked in. Be sure not to leave
any wet spots or streaks—they’ll show up when you apply the stain. Let the wood dry overnight. This step is intended
to seal the wood approximately 60%-75%, which is usually
enough to control blotching and still allow the stain to
3. Wash the partially sealed surface with a mixture of dish
soap and water to “open” the top layer of wood cells so they’ll
absorb the dye easily (Photo 2). This step won’t cause any
significant grain-raising because the surface has been treated
with the stain controller.
4. Hidden blotches will reveal themselves as the water
dries (Photo 3). Areas that are extra-porous soak up more
water. This means they’ll stay wet longer, so they’re easy to
identify. The longer they stay wet, the worse the blotch will
be. Fortunately, even super-absorbent areas can be tamed if
they’re found and treated with extra stain controller before
color is applied.
5. Mix TransFast Medium Brown Water Based Dye
following the label instructions and apply it generously,
using a rag (Photo 4). Allow the dye to saturate the wood,
then remove the excess with clean rags. Allow the wood to
dry until the water has completely evaporated (2 hours).
6. Check the workpiece and selectively apply clear gel
to any blotches or end grain that are already dark enough
from the dye step (Photo 5). This is your last chance for
7. Apply a coat of General Finishes Medium Brown Gel
Stain (Photo 6). Then let the piece dry overnight.
8. Apply two coats of 2 lb. cut amber shellac (Photo 7).
Although shellac is a durable finish, I know that this table will
often be used as a place to rest a coffee cup, so I’ll add a coat
of oil-based satin polyurethane to prevent water rings.
This story originally appeared in American Woodworker October/November 2010, issue #150.
October/November 2010, issue #150
Purchase this back issue.
Click any image to view a larger version.
1. Start by wiping on a strong stain controller to keep the poplar
from blotching when you apply the dye and stain. Make a strong
stain controller by thinning gel varnish with mineral spirits.
2. Wash the sealed surface with soap and water so the dye will
soak in, rather than bead up on the surface.
3. Blotch-prone areas will stand out as the water dries, because
they’re super-absorbent. After the wood has thoroughly dried,
apply an additional coat of stain controller to these areas.
4. Apply a coat of medium-brown dye to create a uniform ground
5. Look again for blotching or dark end grain. Seal any areas that
have gone extra-dark with a coat of gel varnish just before you
apply the gel stain in the next step.
6. Apply a coat of medium-brown gel stain. Gel stain adds
richness to the overall color and helps to keep the dye from
7. Apply two coats of amber shellac to add depth and tone,
followed by a more protective topcoat, if necessary.
Turn green to gold
Oxalic acid works miracles on poplar’s green
heartwood. Simply mix a saturated solution of oxalic
crystals in hot water and brush the solution on the
wood. As the solution dries, the green heartwood will
turn to a golden brown and the white sapwood will
take on a warmer shade of pale. A second application
of the solution after the first has thoroughly dried
usually helps the results—and it can’t hurt. Oxalic acid
is poisonous, so let the surface dry completely and
then rinse it thoroughly with water to remove any acid
that remains. Note that this treatment does nothing to
reduce poplar’s tendency to blotch, so you’ll still need to
follow the recipe to end up with a great-looking finish.
Oxalic acid is primarily used to restore the natural
color of grayed, weathered, exterior wood—it’s the
active ingredient in deck-renewing products. Restorers
and woodworkers use oxalic acid to remove black water
stains from wood. It’s available at most hardware stores.