Basic Wax Modeling

8

9

WAXES
Modeling waxes are available in a variety
of shapes and sizes. The combination of
waxes, oils, resins, etc. determine the
characteristics of given commercially
produced waxes. Color is no indicator
of hardness or use since manufacturers
have their own color codes.
Waxes vary in hardness from machinable
to pliable. Generally, waxes are available
in two or three grades of hardness
designated as hard, regular, all purpose
or soft. Special purpose waxes are also
available.
Technical information regarding melting
temperature, texture, use, etc. is usually
available from the manufacturer or the
retail supplier. Lapidary supply houses
will carry one or more manufacturers’
lines; Vigor, Matt, Ferris and Kerr being
the most common.
Since the manufacturers have their own
formulas, it would be a good idea to try
different brands until the modeler finds
which brands he or she is comfortable
working with.
Use of pure beeswax or paraffin wax is
not recommended due to residue left
in the burn out process or difficulties in
handling in environments with different
temperatures. Concocting “home brew”
is not within the realm of this book.
WAX TYPES:
1. Ring Tubes. Available in the
following designations: center hole,
off center hole and flat side with
hole. They are made in a variety
of diameters, heights and several
degrees of machinable hardness.
Commonly sold in 6-inch lengths,
but many suppliers will have 1-inch
segments sold individually or in
sampler kits.
2. Rods and Bars. Above comments
apply.
3. Carving Wax. Used for sculpturing
and large projects. Available in half
to one pound blocks and slices of
varying thicknesses. Hard to soft
toolable textures.
4. Paraffin Wax.
5. Sheet Wax. Available in 16 to 24
gauge thicknesses. 4-inch squares
and 3 x 6-inch sheets. Hard to soft
textures. Soft is ideal for tracing and
cutting with scissors or cutters.
6. Boxing Wax. Slightly tacky. Will
adhere to itself or other waxes
without the application of heat. Ideal
for forming large models.
7. All Purpose Wax. Pliable at room
temperature. Generally 16 to 18
gauge thickness.
8. Utility Wax. A soft wax used to make
sprues and fill sprue bases. May also
be used to fill minor imperfections
and marred surfaces since it will
adhere to any wax surface without
the use of heat.
10

9. Wire Wax. Available in a variety
of gauges and shapes; round,
half-round, square, rectangular,
triangular, etc., pliable wires, which
may be bent or twisted with little or
no heat.
10. Mitsuro. A special blend of
impression wax, resin and paraffin
wax.
11. Impression Wax. A refined beeswax.
12. Pattern Wax. Mesh patterned wax.
Useful for open work pendants and
brooches.
13. Injection Wax. Used for the
production of duplicate patterns.
14. Water Soluble Wax. Dissolves in
water. Useful when worked with
other insoluble waxes as a form.
When immersed in water, the
insoluble wax shell will remain.
Other Waxes:
Sticky Wax. A hard fast setting wax
used for welding wax parts together
and repairing. Tacky when viscous.
Inlay Wax. Designed for adding onto
or building up patterns.
Wax Solvent:
Commercially produced solvent or
turpentine. Use of acetone to stop
action.
11

12

13

TOOLS:
In addition to tools made specifically
for wax modeling; metal working,
woodworking and household tools may
also be used. Home made tools have
their uses as the need arises.
FOR CUTTING AND CARVING
1. Files. Double end file. Equalizing
files. Needle files.
2. Saw Frame. With a spiral cutting
blade (#3) and piercing blade (#4) .
3. Metal Working Files. Coarse to
medium.
4. Handi-Saw. Hacksaw type blade.
Use for straight line cuts with
minimum drift.
5. Cutters and Chisels.
6. Wax Carver.
7. Light Weight Knife with replaceable
blades.
8. Disposable Blade Cutter (snap off
segments) .
9. Small Portable Drill/Grinder.
Alternative: a flexible shaft machine
with variable speed control.
10. Burs.
11. Drill Bits. Carbon or high speed.
12. Reamer. A hardwood ring sizer with
cutting edge is available (Matt).
FINISHING
13. Emery Paper. 3 to 4/0 grits. Also
useable are aluminum oxide and
silicon carbide papers. Grits 220 - 600.
14. Emery Sticks. Wrap paper around
square or round sticks.
15. Scraper.
16. Ink Eraser. Sharpen to a chisel edge
to clean out grooves, etc. Erase light
scratches.
17. Bamboo Spatulas.
18. Discarded Nylon Stocking for
polishing.
19. Cotton Swab (Q-tip). Useful for
polishing in tight places.
20. Spatulas.
21. Alcohol Lamp.
22. Wax Pen. Electrical tool with wax
reservoir for depositing melted wax.
Waxer/Carver. Electrical tool with
tips for welding, carving, etc.
23. Needles. Set into a dowel or pin vise.
Use for welding and texturing.
MEASURING AND WEIGHING
24. Spring Gauge (degree gauge) . Used
for measuring thicknesses where flat
jaw calipers cannot be used.
25. Balance Scale.
26. Ring Mandrel. Available in steel,
aluminum or plastic.
27. Ruler. With metric and English
markings.
14

OTHERS
28. Oily Marker. Fine point laundry
marker.
29. Divider. School use divider/compass
is fine to use.
30. Pin Vise. Use to hold burs, drills and
needles.
31. Toothbrush. Soft bristles for cleaning.
32. File Cleaner. Cleans wax clogged in
cutting surface of files.
33. Plate Glass Slab - 1/4-inch.
34. Bamboo Tweezers.
35. Sponge. Store soft wax pieces in the
grooves. Wipe excess wax off tools.
36. Wooden Mandrel.
37. Bench Pin (not shown). Cover with
cloth padding.
15

Using a divider, scribe a line around the
ring tube, 20 mm from the top.
1
Use a saw frame fitted with a wax cutting
blade. Mount the blade with the sharp
edges toward the handle.
With your index finger or fingernail as
a guide, draw lightly on the saw to start
the cut.
2
Remember that the saw cuts on the pull
stroke. Saw slowly, rotating the tube as
sawing progresses. Stay well clear of the
guide lines.
3
18

Use a coarse file. Choke up grip, with
forefinger firmly on top of the file.
File flat and parallel to layout lines.
Check frequently.
Scribe center lines. Scribe a short
segment on the flat portion from both
sides of ring. If the lines do not coincide,
the center line will be midway between
the two lines. (See “A” ) .
Reset the divider and scribe a line
completely around the ring. Repeat in
the other direction. (See “B” ) .
44
Extend the center line to the bottom of
the shank.
5
6
19

Scribe a reference line (about 1 mm wide)
around the inner and outer diameter,
and also up the straight side.
Do this on both sides of the piece.
7
Using a circle template or free hand,
scribe lines as shown on both sides.
Check for symmetry.
8
Scribe a straight line from the inner
scribed circle, parallel to the top.
Do this on both sides.
See photos.
9
20

At the bottom of the ring, from a point
about midway between the center line
and the edge of the ring, scribe a line
connecting to the line drawn in Step 9.
Do this in four places.
10
The ring should now look like this:
TOP
BOTTOM
FRONT &
BACK
SIDE
21

Hollow out underside of the dome. Refer
to Fig. 1 below for scribing the outline to
follow.
FIGURE 1
Finger
hole
23
Wax removed from areas that will not affect the design of a
piece will reduce the weight of a casting.
This is particularly important when precious metals are
used. Normally, the dome would be hollowed out to
a thickness of .6 to 1 mm. For this exercise, strive for a
thickness of 1 to 1.5 mm. Mark the thickness dimension
inside of the finger hole and scribe a long oval as shown in
the developed view.
RIGHT
RIGHT
WRONG
Equal
Uniform
thickness
Thicker at the
finger hole
Thinner at the
finger hole
Equal
Developed view of the area to be removed
26

Having marked the limits for hollowing,
use a small spoon shaped carver. Scrape
out the wax as shown.
A flexible shaft machine could be used
but the purpose here is to develop
manual dexterity.
Carver
Wax
Measure the thickness with a caliper.
Hold the ring up to a strong light source.
Light and dark areas will indicate relative
thicknesses.
24
Irregular surfaces may be smoothened
further by using a larger carver which
more closely fits the contour of the cavity.
25
26
27

COMMENTS:
Shrinkage in castings.
Molten metal occupies more space than solid
metal. Consequently, the cast piece will be
slightly smaller than the wax model. Shrinkage
is more pronounced in gold castings than silver
or platinum castings. The amount of shrinkage is
0.5% or less and therefore is negligible. However,
in making a ring model, it is advisable to size the
ring 1/2 size smaller than required to allow for
finishing. See appendix for ring sizes.
Weight of castings.
By and large, commercial waxes have a specific
gravity of less than 1 (0.97 to 0.99). The specific
gravity of sterling silver is 10.46, 14K gold is 13.4
and 18K gold is 15.5.
Allowing a specific gravity of 1 for wax, a model
weighing 0.7 grams will produce a casting
weighing:
0.7 x 15.5 = 10.85 gm of 18K gold.
0.7 x 13.4 = 9.38 gm of 14K gold.
0.7 x 10.46 = 7.32 gm of sterling silver.
To determine the cost of a casting, multiply the
cost of the metal per gram by the weight of the
casting. It is apparent why it is important to keep
the weight of the wax model down.
Checking a model for distortion.
In the process of making a ring model, it may
bend or distort. A substantial distortion will
be readily noticeable. Slight distortions may be
checked by mounting the ring on a calibrated
ring mandrel and checking it in reference to the
markings.
28

VARIATIONS OF THE DOMED RING
The basic ring
Stone & sculpture
Sculptured top
POINT OF DESIGN:
There are many ways to alter the basic dome construction.
By removing portions in one place and adding to another;
creating new designs and still preserving the basic structure.
29

30

PROJECT NO. 2
A RIPPLE PATTERNED RING
Required: a flat side ring tube with hole 1-1/8-inch x 1-3/8-inch high, 18 mm thick.
The ripple or “S” wave configuration is commonly found in fashion jewelry.
In addition to what was learned in the previous project, more care in layout (ripples)
and finishing (grooves) is involved. The complexity of hollowing out the underside
is more taxing. However, it can be done. Just have the patience to follow through!
Carvers with offset blades will be an asset for this project.
4 views of the completed ring.
31

Construct a dome ring as in the previous
project.
Using a fine line marker, draw the wavy
“S” lines as shown on pg. 31. An ink
eraser will remove errant lines.
1
Check for balance. Lightly scribe over
the inked lines. Repeat several times
until the depth of 1 to 2 mm is reached.
2
Using a carver or a knife, expand the
scribed lines into V grooves. Check for
uniformity, segment to segment, for size
and depth.
3
32

Bevel the grooves with a shaver as
shown. Since it is a specialized tool, you
could use a knife, file or carver instead.
See modified tools on pg. 44.
With the same tool used in Step 4, gently
round the segments into smooth convex
forms.
4
Smooth the ripples with progressively
finer abrasive paper.
5
400 grit
paper
3/0 emery
paper
6
33

Cut an ink eraser to a chisel edge. Use it
to clean the bottom of the grooves.
7
Finish the balance of the ring; fit and
width for wearing comfort. Use finishing
paper and polish with stocking scrap.
See the side view of the ring.
8
Scribe area to be hollowed out (about 1
mm at the finger hole). Refer to Fig. 1 on
page 26.
9
34

Hollow out the underside using a flexible
shaft machine with a ball bur, if available.
Othewise, use a carver. Caution: do not
cut into the grooves on the top side. Use
the gauge shown in Fig. 2 below.
Hold the ring to a light source. Note the
location of the ripples and scrape lightly
until the transmitted light through the
bottom of the groove and the ripple
portion are the same. Clean the cavity
carefully.
10
11
Figure 2
A wax plate gauge for estimating thickness.
Where conventional gauges for measuring thicknesses
cannot be used (e.g. from the bottom of a groove as
experienced in the previous project) a gauge may
be made for transmitted light comparison. The
construction is self-explanatory. The gauge should
be made from the same wax (type and color) as the
article being compared.
0.6 mm 0.8 mm 1.0 mm 1.2 mm
35

LOST WAX CASTING PROCESS
A BRIEF DESCRIPTION
While this book is devoted to creating wax models, it is important for the modeler to know
what takes place after the model is made.
There are many books written on casting and wax modelers should familiarize themselves
with spruing techniques, investing, and casting whether they do their own casting or not.
Models should be finished as smooth and faultless as possible since imperfections will be
readily noticeable after the piece is cast, at which time repairs will be tedious to impossible.
A simple centrifugal machine is illustrated here, but other casting equipment – vacuum and
hand pressure units – are used as well.
CRUCIBLE
COUNTER
WEIGHT
BALANCING
ARM
FLASK
ROTATION
RELEASE PIN
1. The casting machine is balanced with the metal to be melted placed in the crucible and
the invested flask in the cradle.
2. The flask is placed in the burn-out furnace for the prescribed length of time. Shortly
before removal time, the balance arm is rotated clockwise two or more times and held
there by raising the release pin.
3. The metal is then melted with a torch. The flask is removed from the furnace and placed
on the cradle. At the proper moment, the machine is allowed to spin causing the molten
metal to enter the cavity left by the burned out wax.
106

FROM WAX MODEL TO METAL CASTING SIMPLIFIED
Finished wax model Sprue is added Assembled to a crucible
former and flask
Invested plaster is
added
See casting
process
Air bubbles removed by
vacuum or vibration
Placed in burn-out
furnace
Burn-out
completed
Remove from casting
machine
Immersed in water to
break up plaster
Sprue removed
Ready for
finishing
107