Brushing Shellac

Brushing Shellac

Apply shellac like a pro.

By Mitch Kohanek

If you aren’t
brushing shellac
these days, it’s either
because you’ve never
tried it or you’ve had
a bad experience.
Let’s see if I can
change that.

The number one reason people abandon
shellac is they expect it to behave like
polyurethane. But shellac and poly are different
animals. For starters, shellac uses fast-drying
200-proof grain alcohol, or ethanol, as a
solvent. The non-toxic ethanol is “poisoned”
with small amounts of toxic solvent such as
methanol or acetone in order to render it
undrinkable and escape liquor taxes. Ethanol
evaporates quickly and requires a different
method of application and tools than slowdrying
polyurethane varnishes.

A skilled professional can make brushing
on any type of coating look easy. But,
like any skill, applying shellac takes practice.
Were your first hand-cut dovetails perfect?

Practice brushing on a two-foot square
panel before you touch anything of value. It’s
easy to sand the panel back down to the wood
and brush it again and again. After you get
comfortable with brushing the panel, go to a
garage sale and purchase a small table or
chair. Lightly sand it with some 320 grit sandpaper
and practice brushing on real furniture.

 

Shellac’s advantages

There are two reasons for using any finish:
The first is to enhance or change the original
appearance of the wood; the second is to protect
it.

Shellac creates a warmth and depth that
makes inexpensive woods look expensive and
expensive woods look even more impressive. So you’re covered on the good looks front. As a rule
of thumb, use light colored shellac on light woods
and a dark colored shellac on darker woods.

Let’s look at the protection issue. Many people
refrain from using shellac because they’ve heard it
offers little protection. But how much protection
does the project really need, and from what? A
kitchen table needs a whole lot more protection than
a jewelry box or a grandfather clock. Shellac may not
be the best choice for a kitchen table but for many
other projects shellac offers plenty of protection.
Besides beauty and protection, shellac has other distinct
advantages: Unlike polyurethane, shellac is
repairable and can be fixed without stripping off the
old finish. Also, shellac’s rapid cure leaves little time
for dust to settle into the wet finish and you can
recoat in less than an hour. Finally, shellac does not
require sanding between coats saving you time and
elbow grease.

In recent years, protecting the environment has
become another criteria for choosing a finish.
Shellac stands out as one of the greenest and least
toxic coatings available. Shellac is a pure, natural finish
that’s often used to coat fruits, vegetables and
candy. As always, good ventilation and an organic
vapor mask are recommended.

 

Two keys to success

#1: Thin your shellac to a water-like consistency
(Photo 1). A 1 to 1-1/2 lb. cut is ideal for beginners.
Pre-mixed shellac is usually a three-pound
cut (the exception is Zinnser Bulls Eye Seal
Coat, which is a 2 lb. cut). This means three
pounds of shellac has been mixed into one gallon
of alcohol.

#2: Use a high quality brush. A good brush will hold
a lot of shellac and apply an even coat without
leaving ridges or pronounced brush marks.

One good starter brush is the Winsor & Newton
Regency Gold 580 series (Photo 2) made with Taklon
synthetic nylon. Another one is the Loew Cornell
7550.

 

Brushing techniques

There are two ways to brush shellac: Lay down a
thick layer using a slow gravity-feed method or
paint it on thin and work fast. I use both of these
brushing techniques on a small tabletop: the gravity-
feed method on a molded edge and the rapidbrushing
method on a top. I prefer the gravity
method on the edges because the brush can cover
the whole edge and leave a relatively thick, even
coat without worrying about ridges. I use the fast
and thin method on the top of the table because
it’s less prone to leaving ridges and brush marks.
For this table I will use a 1-1/2 lb. cut of shellac and
a 2 in. Taklon bristle brush.

Set up a raking light so it washes across the area
you are brushing (Photo 3). Shellac sets up fast and
is pretty unforgiving if a brushing defect goes undetected
even for a minute.
The light will illuminate
any runs and “holidays”
(missed spots) before
the shellac has time to
set. If you notice a brush
mark or a holiday, and it’s been longer than 10 seconds, leave it alone.
Going back will only make it worse. A minor amount
of sanding with 320-grit sandpaper will get rid of the
brush mark. A holiday will disappear when you apply
the next coat.

Charge the brush with some denatured alcohol
(Photo 4). Then brush some clean paper to draw
out the excess alcohol. Dip your brush into the shellac
3/4 of the way up to the ferrule. Hold the brush
with your fingers firmly on the ferrule.

When brushing a tabletop, I do the edges first
using the gravity feed technique (Photo 5). Don’t lay
down the shellac so heavy that it forms a run, but do
maintain a consistent wet look. End the stroke by
exiting off the edge of the table like an airplane taking
off. Return to the corner where you began and
land your brush in the opposite direction like an airplane
touching down (Photo 6). Aim for a few inches
inside the wet shellac and run the brush past the
corner, taking off as you did in the first stroke.

Work your way around all four edges, taking off
and landing as you go. If you should accidentally hit
the top, immediately wipe it off with a clean rag.

Switch techniques to brush the flat part of the
top and use small rapid strokes to lay down a thin
coat. Start the stroke by landing your brush near an
edge. Brush on the shellac with a rapid back and
forth motion. Shoot for three 10 in. strokes every
second. When the brush begins to empty, recharge
the brush and land it in the dry area just ahead of
where you left off (Photo 7). Do the airplane takeoff
stroke once you reach the table edge (Photo 8).
Don’t let the brush hit the edge of the table on a
return stroke or you will create a drip for sure.
Brush with the grain all the way across the table. On
a large surface it is necessary to overlap your strokes
(Photo 9). Unlike the gravity feed method that lays
down a heavy coat in one continuous motion, this
technique lays down a thin layer of shellac with multiple
brush strokes. A thin layer sets up fast and
does not leave brush marks.

By the time the first coat is done the shellac will be
dry enough to apply a second coat. You can take
advantage of shellac’s fast drying time to apply three
coats one after another with no time for dust to settle
in and ruin the finish. With a 1 or 1-1/2 lb. cut of
shellac it will take about three coats before you start
to develop a noticeable build. I generally try to give
the object three light coats for the first setting to seal
the wood. I like to lay down a minimum of 9 layers in
3 or more settings for a good build. The time frame
for additional coats is dependent on temperature
and humidity. If your bristles seem to be dragging
while applying another coat, then the previous coat
has not yet cured – give it more time to dry. The first setting will leave the surface of the wood rough. A
light scuff sanding with some 600-grit sandpaper will
remove the whiskers. After that, sanding is not necessary
until after the final coat has cured and it’s time
to rub out the finish.

Allow the shellac to fully cure for a few days. Then,
do a final rubout. Shellac can be rubbed out to any
sheen you want, high gloss or matte.

With enough practice, you will develop your own
preferred blend of shellac and alcohol, your own
speed for brushing and your own feel for how wet
and thick to lay down the shellac. Eventually, you’ll
get into the different types of brushes and shellacs
that are at your disposal. Trust me, it’s a lot of fun.

 

Brush cleaning

A few sloshes in some clean alcohol will get 95 percent
of the shellac out of the brush (Photo 10). Pad
the brush with a paper towel or clean rag (Photo 11).
Then form the bristles in their proper shape (Photo
12) and you’re done. The next time you need to use
the brush, place it in some clean alcohol for a few
minutes, wipe off the excess on a paper towel and
rock and roll.

Finishing with shellac is like any other aspect of
woodworking – it takes time and practice to develop
the skill. Ultimately, you will find yourself joining the
ranks of those who enjoy using a finish that is safe,
fully repairable and has a proven historical track
record for stability and beauty. That’s something really
nice to pass on to future generations.

Good luck, and have fun!

Source

(Note: Product availability and costs are subject to change since original publication date.)

Hofcraft, hofcraft.com, 800-828-0359, Winsor & Newton
Regency Gold 580 Stroke Brush, 1-1/2 in., #WN580-1-1/2”;
Loew-Cornell 7500 Flat Sky Wash Brush, 2 in., #LC7750-2.

This story originally appeared in American Woodworker September 2008, issue #137.

Purchase this back issue.

Click any image to view a larger version.

1. Thin your
shellac
before use.
Store bought
shellac is typically
a 3 lb. cut.
Mix it 1-to-1
with denatured
alcohol for a
user-friendly 1-
1/2 lb. cut.

2. A 1-1/2 or 2 in. square
flat brush
made with
golden nylon, or
“Taklon” bristles
is a great
starter brush
for applying
shellac. It’s
best on flat surfaces
but it can handle a
cabriole leg with a little practice
and it won’t break the bank.

3. Set up a light
source
at a low
angle so it rakes the
work area. A raking
light will show
defects like drips
and “holidays”
(places you missed)
before it’s too late
to correct them.

4. Charge the brush
by soaking it in
denatured alcohol for
a few minutes before
use. This helps the
shellac flow better
from the brush.

5. Shellac the edges
first.
Start the
brush stroke an inch or
two from the end.
Move the brush slowly
to lay down a long,
consistent wet layer of
shellac. Nestle the
edge of the brush in
the fillet to keep excess
shellac from accumulating
and running
when your back is
turned.

6. Come back to finish
the bare spot where
you started the stroke.
Think of your brush as
an airplane. Land the
brush near the unfinished
end and then lift
off right at the edge to
avoid snapping the
bristles over the edge.
Lifting off prevents
pools of shellac from
being left at the edge
and turning into drips.

7. A completely different brushing technique is used on
the top surface. Instead of a long and slow stroke, use
short fast strokes. Land the loaded brush in a dry area and
with rapid back and forth strokes work the shellac back
into the wet area. Aim for a thin, even layer of shellac.

8. Finish the stroke at the edge. Lift the brush as it
passes over the edge just like an airplane taking off.
This prevents the brush from pushing shellac over the
edge and dripping down the freshly finished edge.

9. Overlap your strokes on a large surface. Any time you
re-wet the brush, land the brush in a dry area. Use a
back and forth stroke to blend the new stroke into the
wet shellac ahead of it and beside it.

10. When the
brushing is
over
, cleaning your
brush is a breeze.
Just swish it around
in a container with
clean denatured alcohol.
This will clean
out most of the shellac
from the brush.
Unlike varnish or
water-based finishes,
it okay to leave some
residue in the brush.

11. Pull the brush
across a folded
paper towel or
rag to remove the
excess alcohol.

12. Form the bristles
so they
dry in their proper
shape. The brush
will dry stiff from the
shellac left in the
brush. To use again,
just soak the brush
in alcohol for a few
minutes.