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Woodworking
Times Archives
From March - April '97:
An Elegant Poster Bed "Made Simple"
Plough Plane Thread Repair
A Grand Day Out
Kitchen Basics 3
From January
- February '97:
Super
Smooth Oil Finish
Ron
Clarkson - Furniture Maker Extraordinaire
Old Time Whittling
Kitchen Basics 2
Woodworking Poetry
From
November
- December '96:
Making
Your Own Quality Oil Stain
Workbench
Story
Ryobi
BT3000 Table Saw Review
Kitchen
Basics 1
Woodworking Humor
From
September
- October '96:
Veneer
Basics
Restoration
of a XVIII Century French Secretaire
All
About Oil Based Varnish
Wintertime
Woodworking
From
July
- August '96:
Finishing
Oily Woods
Review
Of Woods Of The World CD ROM
Sharpening
Systems
Polyurethane
Adhesives
Scraper
Essay
Michael
O'Donnell
From
May
- June '96:
Finishing
Cherry
Makita 9820-2 Electric Sharpener
Reproduction
Hardware Styles
She
Is a Woodworker!
From
March
- April '96:
Woodworking
Vacation
The
Chestnut Story
Woodworking
Attitude
Useful
Articles On Other Web Sites
From
January
- February '96:
Table
Saw Maintenance
Evolution
of an Entryway
News
From Sweden
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By Sal Marino
Traditionally, some of the world’s most colorful woods like rosewood, teak,
ebony and cocobolo are often used to build musical instruments,
decorative boxes, jewelry, accents and trim on furniture.
Recently though, many of these woods are being used to build
whole pieces or sets of custom furniture. As more are being
used by not only professional but amateur woodworkers, many
people are running into difficulty when it comes to finishing
of these woods.
The main problem lies in the natural oils and resins that
are contained within woods like rosewood, teak cocobolo, etc.
The oils create two main problems.
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When oil based finishes like varnish, polyurethane, Danish
oil finishes, and others are applied over the wood, the
finish sometimes takes a very long time to dry. All of
these type of oil based finishes dry by absorbing oxygen.
The natural oils and resins contained in exotic woods
will slow down the drying time by retarding the absorption
of oxygen into the finish. Sometimes, if you happen to
get stuck with a very oil piece of wood, the finish may
stay tacky for weeks.
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Adhesion. While other finishes like nitrocellulose lacquers,
pre-catalyzed lacquers and water based finishes dry better
over oily woods, the oils may prevent these finishes from
adhering properly to the raw wood.
Below, I have included a few different types of finishes and finishing
techniques that I have had success with, but first, before
applying any finish, you must perform the following steps
to remove any oils that may be on the surface of the wood.
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After preparing the wood by usual methods of sanding,
clean all sawdust off the surface.
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Using a rag lightly dampened with a quick evaporating
solvent like acetone, lacquer thinner or denatured alcohol,
wipe the whole surface down. This gets all the natural
oils off the surface of the wood, but you must work quickly
to apply your first coat of finish, for if you don’t more
natural oils will bleed onto the surface.
While many exotic woods are rarely stained, because the natural
color of the wood is so appealing, all have to have some
type of finish applied to protect against abrasion, moisture,
dirt, dust and sunlight. Over the years, I have had the
opportunity to try many finishes and finishing techniques
over oily woods, and I have had the most success with the
following:
1. Shellac Sealer / Natural Resin Varnish Finish.
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If you are going to be finishing a piece of furniture
that is going to get a lot of use, (like a table) you
will want to use some type of topcoat finish that will
protect it against abrasion, as well as spills, dirt and
dust along with making it easy to maintain. This finish
has worked well for me.
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After wiping down the surface with quick evaporating solvent,
(acetone, lacquer thinner) apply two thin coats of shellac.
I use 3 lb. cut clear shellac and reduce it 50/50 with
denatured alcohol. Apply the two coats by either spraying
or brushing with high quality natural or china bristle
brush. Let first coat dry about 2 hours before applying
second coat.
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This will seal the surface and prevent any more natural
oils in the wood from bleeding back to the top. Let these
two coats dry at least 2 days.
Lightly scuff sand the shellac with 400 grit paper. And
wipe dust off surface. Next, apply 2 to three coats of
a natural resin varnish. DO NOT USE A POLYURETHANE OR
ANY VARNISH THAT HAS POLYURETHANE IN IT. IT MAY NOT ADHERE
TO SHELLAC.
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I use a varnish manufactured by H Behlen & Bro. This is
called Behlen’s Rock Hard Table Top Varnish. It is a natural
resin varnish that contains no poly. Reduce each coat
approx. 20 percent with Behlen’s Rock Hard Reducer. This
works out to 4 parts varnish and 1 part reducer.
I use a foam brush to apply this varnish, but if you are
used to using a bristle brush and get good results, stick
with it. Let each coat dry at least 24 hours (longer if
you are in a humid area). Scuff sand very lightly with
320 grit paper between coats. After the last coat is applied,
if the sheen does not look even, you may apply a few additional
coats until you achieve a uniform sheen.
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This is a gloss varnish, if you wish to obtain a semi-gloss
or satin finish, simply wait about 2 weeks for the finish
to cure and then rub out with 600 grit paper and rubbing
oil or use 0000 steel wool or Scotchbrite or Sunbrite
(these are synthetic non-woven abrasive pads that replace
steel wool. Purchase the fine type. The light gray color
is usually equivalent to 000 or 0000 steel wool.
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If desired, you may also apply a coat of high quality
paste wax after rubbing
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On furniture or wooden objects that don’t need maximum
protection such as a wall clock, dresser or just trim,
I have often just used a few coats of shellac and the
applied a coat of paste wax over it.
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After wiping down the surface with quick evaporating solvent,
(acetone, lacquer thinner) apply four thin coats of shellac
using the same mixture and process as described in the
previous process.
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Let the four coats of shellac dry at least 3 days, Then
sand lightly first with 320 grit paper to remove any dust
nibs and smooth out any brush marks. After sanding with
320, use 600 grit to smooth the surface and leave a mellow
sheen.
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Wipe off dust and apply a coat of high quality paste wax
such as Briwax or Antique Wax. Apply the wax with a soft
lint free cotton cloth, let it haze over, then buff it
out with a clean cotton cloth. This technique will yield
a very mellow, low luster finish that is beautiful not
only to look at but to touch.
3. For A Natural Look- Simply Wax
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When I have to finish a decorative wooden object that
will not be handled much, therefore needs little protection
but also has to look and feel as close as possible to
its natural appearance, I simply apply a paste wax only.
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Here the color of the wax is important. If you are finishing
a lighter colored wood such as teak, use a natural or
clear colored paste wax so the natural color will not
change much. On the other hand, if you are finishing a
darker wood, such as rosewood or cocobolo, I suggest you
use one of the colored waxes, such as Briwax. If you use
a light colored wax on dark woods, the wax may build in
the pores and make the pores appear light. Dark wax will
blend in better with darker woods and even accent the
pores.
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Briwax comes in a number of colors. Along with clear,
it is available in Dark Brown, Light Brown, Antique Mahogany
(reddish brown good for rosewoods), Golden Oak and other
colors.
REMEMBER.
ALWAYS TEST FINISHES AND FINISHING TECHNIQUES ON SCRAP BEFORE
USING THEM ON YOUR GOOD WORK.
Sal Marino is a woodworker
and a finishing expert from New York. He works for Constantine's.
He teaches woodworking classes at Constantine's, offers private
instruction, lectures around the United States and is a finishing
consultant to many woodworking and restoration companies.
He is also the author of numerous woodworking articles.
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