Fine Furniture Finishing Newsletter, Issue 2
This issue's topic: mixing colors, and a few questions from viewers.
Let's start with a couple of questions that have shorter answers before going
into the more general inquiry into color mixing.
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"Alright, so I'm becoming a convert to sanding; how can you tell when it's time
to change the paper?"
It's time for a change when either one of two things happen: the sandpaper
is clogged with whatever you're sanding (wood dust, varnish, paint, etc.) or the
abrasive gets worn down. Oftentimes you can clear the paper of wood dust or
dried paint-type products with a stir stick or stiff brush (old toothbrush is good)
or even another piece of sandpaper, and keep going. When you're sanding
fresh finishes, especially water-based products, there is a tendency for them to
form slightly sticky "balls" on the surface of the sandpaper. These are a real
pain in the neck, because they often form quickly, after just a few swipes
across the surface, and just a couple of them hold the surface of the paper
away from the surface you are trying to sand so that nothing is happening.
You can pick at those first few miscreants with a fingernail and pop them right
off, but it will rub your nail down to nothing soon enough, so perhaps it's
better to keep a stir stick or old screwdriver handy to pick at them instead. The
newer, green sandpaper seems to be a little better with latex at staying free of
clogs. Otherwise, start with a new piece when these little clogs overwhelm the
current piece, or, whenever your patience wears thin, whichever comes first.
When you have the time, the problem can be minimized by letting the
finish dry longer before sanding.
The other situation is knowing when the sandpaper has just plain worn out from
use. When you are wet-sanding you will not normally get any clogging because
the water carries away the slurry before the paper gets loaded up. ( A small
sideline here: If you're still getting those little sticky balls of finish on your
sandpaper when you're wet-sanding a "fresh" finish, try adding a drop or two of
liquid dishwashing soap to the water you are using, this will usually keep them
from forming. If it's still happening, the coat is not dry (hard) enough and must
have more time to dry before sanding.)
The easiest way to tell when it's time to change the sandpaper is to run
your finger lightly over the part of the paper you've been using, and do the same
over a part that is still new. (The part that is wrapped around a sanding block,
for example.) When you can feel a difference between the rough, new part, and
the smooth old parts, it's time to change it. The abrasives on the more
expensive papers (silicon carbide, aluminum oxide) last longer than the lesser
papers (flint, garnet) and so are often less expensive in the long run. I find that
sandpaper never adds up to much of an expense on any given project and am
quick to change it rather than rub longer.
(Another sideline: I love sanding [by hand, not with a machine] because it's a
great time to listen to music; you can really get into both at the same time! It
can also be a great time to shoot the breeze with someone you like, as it's
easy to pause or stop or move around when necessary or for dramatic effect.)
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"Those were beautiful mahogany chests you used in the tapes. Where can I
get them?"
The chests, and the jewelry box that was on the first tape, are both from The
Bartley Collection (800-787-2800, http://www.bartleycollection.com/ ).
My dad had built several of their kits over the years (with me being a lucky
recipient of one of them) and in looking at their catalogue I thought that one of
those chests would make for a good demonstration of several materials and
techniques. Not to mention that I thought I'd like to own a pair of them for
myself. And as it turns out, I like it very much.
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"How can I tell what color to add to another to get the final color that I want?"
Color theory and color practice isn't nearly as difficult as many people think it
is, once you have a few basics. The easiest way to get the basics is to buy an
inexpensive color wheel from your paint store or artist's supply. Even if you
already know that blue mixed with yellow will make green, the wheels are quite
handy to have around, especially the ones that also have tints (white added)
and tones (gray, or black added). After awhile you'll get amazingly fast at
guessing. One of my many jobs as a young(er) person included working in a
paint store. When things got slow, we would sometimes have contests to see
who could match a color sample the fastest. This wasn't a total waste of our
employer's money as it enabled us to more quickly serve customers who were
always asking us to match something or another.
As far as practically mixing a color for a specific project, start small! That is,
start with a small quantity of paint that you mix to the right color before you
gallop off trying to mix a pint. I've watched people keep adding and adding to
try to get their mix lighter or darker until they ended up with a gallon of paint
when they only needed a few ounces (OK, sometimes those people was me).
As you'll discover, it only takes a few drops of some strong colors (pigments)
to tint a lot of white. And conversely, sometimes a little white added is all
that's needed to lighten up a deep color. So start with small quantities until you
get the color you want, then increase the amounts by the approximately same
ratio till you have the several ounces or pint or quart or whatever amount you
think you'll need for the project. Now by the time you've made the slight final
adjustments, you should have just a little more paint than you really need.
Why a little extra?
Because running out of paint with a six by six inch square of un-painted area
still to go is one of the definitions of a bad thing. You end up madly dashing
around trying to brush out the mixture a little thinner, or trying to remember the
proportions again as you attempt to quickly mix just a little before the other
starts to set...and that's if it's in oil, -forget it if it's in latex or acrylic!
Here are my suggestions for the materials themselves that I would try to keep
around if you think you'll do much with anything except applying single-color
opaque paint projects. For a single color over the whole surface of a project,
particularly if it's very large, it's easiest to select a color from a dealers color
swatches and have them make up a quart. Otherwise, here's my general list:
A quart of pure white, the same of pure black, in regular house paints.
Tubes of artist's colors in the earth tones such as
Yellow ochre
Burnt sienna
Indian red
Raw umber
Burnt umber
At least one tube of each of the three primary colors, red, yellow, blue
It will be easier to mix colors if you have a wider array to choose from; for
example, a warm red and a cool red, etc.
All of these would be your choice of water or oil-based, depending on which
medium you prefer. If you use both, you'll want to have a more or less complete
set of each. (And remember, don't mix 'em, or you'll have a mess!)
If you will be working with larger areas of intense hues, you will also need to
buy some cans of colors that are very close to what you want; it's difficult to
modify quantities of stronger colors without using up a whole tube or more of
your artist's colors.
Other stuff to have around would include stir sticks, (I upend them in an empty
gallon can after I use them, when dry you can use them again) some smaller
sticks for smaller quantities (like popsicle sticks or tongue depressors), an
artist's palette knife, some foil or paper plates, and last, but never least, the
usual assortment of empty jars and cans; somehow it always seems the more
the better.
Here's a hint to make mixing easier: avoid adding small quantities of tube color
into large quantities of house paint, it's hard to get that little bit of stiff color to
disperse fully into that large amount of relatively thin color. The little lump will
sit there, just out of range of that stir stick that you're trying to poke it with,
like trying to grab a piece of eggshell out of the bowl.
Instead, pour or dribble a little solvent (water or mineral spirits) over some of
tube color that has been squeezed out onto a palette of some sort, -I usually
use a piece of foil, and mash/stir the solvent/paint until you have a pour-able
color. This is where I use either a palette knife or an old stiff brush to mix with,
a stir stick doesn't work too well.
Now you can use this looser paint to modify the color of some housepaint, or
add some housepaint to this tube color to decrease its intensity, or whatever
combination of several tube colors with one or more housepaints. The point is
that you will be able to get a thorough blending to get an accurate color
through the whole mix. An incomplete mixing will find you hitting "pockets" of
tube colors as you're brushing out your project, creating an effect that you
probably hadn't intended.
Obviously all of this applies equally to mixing up color/glaze mixtures for any
of the processes that use glazing such as antiquing, marbling, etc.
And finally, I recommend for everyone, but particularly for anyone who feels a
little "color-challenged" to spend an hour playing with paint on some paper or
a piece of melamine. Take each of your tube colors and see what happens
when you add increasing amounts of white paint to them. Do the same with
black. Try mixing some of your black and white together to see what kind of
grays you get. Add a little dab of your tube colors to the grays. This is where
you will get a range of wonderful colors for subtle basecoat/antique coat types
of projects.
Mix varying amounts of two tube colors together to see what you get. Take
blue and yellow, for example. Notice the range of greens from blue-green to
greenish-yellow that you get. Try adding a little white to see what kind of a
pastel you'll get. Or add a little earth color to tone down a bright green into a
softer, more subtle color.
This can end up going on for hours, if you enjoy it. And it will certainly be
handy in the future, increasing your awareness of the possibilities available to
you. Don't forget, all of the above applies equally well to mixing up wood stains
or dyes as well.
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My featured product of Issue Two: artist's colors. Oil colors are available pretty
much just in tubes, acrylics are often found in jars or tubs, as well. Unless you
plan to use a fair bit of one color, I would stick to the tubes with the acrylics,
they last longer without drying out. And buy the lesser priced or student lines,
rather than the more expensive "artist" grades. You'll often be using larger
quantities, and the student grades are plenty high quality.
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Please forward this newsletter to interested friends.
Best wishes,
David Sorg
