A Technique for Dopping with Black Wax
by Bob Keller
When I began faceting I was taught to dop using wax, and I
still use it. Wax is fast, cheap, it works, and it is not
difficult to use, although I might be of a different opinion
had I not been introduced through demonstrations to the
process by another faceter who was proficient with wax
I use a black wax which is sold by the Graves Company as
item 13-062 in their catalog. It is inexpensive at 4 sticks
(1 lb.) for $8.50. There's enough wax in one stick to dop
many faceted stones. I find the 1/4 lb. sticks are unwieldy to
manipulate and work with due to their size, so I cut them up
into handier sized pieces prior to use.
The melting temperature is given as 165 degrees F. and this
technique uses the wax heated to a liquid state. Of course it
may not be suitable for use with materials which are very heat
sensitive, but it is compatible with commonly faceted
natural materials such as quartz, beryl, tourmaline and
garnet. Earl Zoeller, who teaches at Old Pueblo Lapidary
Club and introduced me to this wax, uses it without heat
related problems even for dopping opals.
For heat sources I use a Master Mechanic propane torch, the
garden variety, hardware store kind that consists of a nozzle
screwed onto a standard propane cylinder, and an old electric
clothes iron. There are more ergonomic torches available,
notably the Blazer hand torch, which burns butane and is
refillable from charges for butane cigarette lighters. I
pressed the propane torch into service prior to acquiring a
Blazer of my own. At about $60 or so the Blazers aren't cheap,
and somehow I've just never gotten around to shelling out for
one. The flame and heat output on my propane torch throttle
back nicely, and it works for me. I'll probably get around to
acquiring a Blazer one of these days, but it seems like I
almost always have some necessity of higher priority on my
faceting want list.
The iron was a second hand store item that's mounted upside
down on a simple wood cradle, so the heated flat surface is
level and facing up.
I use the iron as a pre-heater for the rough. I have the
thermostat on the iron marked where it gets just a little
more than hot enough to melt the wax, but well below
smoking or burning it. I bring the stone up to heat on the
iron gradually in half a half dozen steps or so spread over
about 15 minutes. The general idea is to not thermally shock
the stone with a sudden or uneven change in temperature, so
it is gradually brought up to the working temperature of the
wax. Like coming to Tucson during the summer, it's not the
absolute temperature per se that kills you, it's the
This technique for black wax involves some preparation prior
to applying heat.
One pitfall is not having an adequate selection of dops.
The largest available dop compatible with the (planned)
finished size of the stone should be used to maximize the
area and strength of the wax bond. The problem with not
having the one that's 'just right' on hand is you can't use
the one that's too big, so you wind up using the one that's
Dops should be scrupulously clean - wax from prior projects
should not remain on them, including inside the cones of
cone dops. Drugstore variety isopropyl alcohol works as a
solvent for the black wax and I have also used acetone and
MEK depending on what was handy.
I keep a small jar filled with solvent for cleaning dops.
I just open and drop in those that need cleaning, close,
and let time do most of the work. Wiping with a soft rag
or paper towel is usually all that's required to finish
the job. An X-acto knife with a pointed blade is handy
for removing any stubborn residue from inside cones or
other nooks and crannies.
I find the thermal characteristics of brass are the most
user friendly for dopping with the black wax. It seems to
have just about right heat transfer and retention. I also
use black wax successfully with steel dops. Steel heats up
slower and retains heat longer, so you just need to be a
little more patient and judicious with the application of
If you keep the heat on steel dops continuously until the
stone end gets hot enough to melt wax, there's often
enough heat built up internally in the dop that even
though you remove the heat source when the wax begins to
melt, it continues conducting to the stone end and next
thing you know you've got black wax flambeau.
I have only tried to wax dop with an aluminum dop once. I
found aluminum to be difficult to use because it cools down
too quickly to give you much working time for tweeking the
centering of a stone or creating a wax fillet between the
stone and the dop.
I sometimes wipe and dress the stone end of my dops with 320
wet-dry, which leaves a clean, fresh surface and fine
scratches in the brass. Maybe superstition, but I think the
fine scratches may help the wax bond. I'm sure the clean
I use the transfer fixture as a clamp to hold the stone in
position against the dop as things cool and the wax hardens.
I usually cut pavilion first, so a temporary table is ground
on the rough to serve as the plane of attachment for the
crown side dop. I've always used a flat dop against flat
surfaces, but I know other wax doppers who prefer to use a
cone against flats on the theory that when the wax inside
the cone cools it shrinks, creating a suction. There
might be something to that, as the wax definitely expands
when it is heated, and a good wax bond appears to be gas
tight. In any event, their stones don't fall off and cones
as well as flats have proven serviceable against a temporary
A 'cold' run is part of the preparation. The crown dop is
placed in the transfer fixture which is set down on the
work surface so that the flat of the crown side dop is facing up
and horizontal. The fixture needs to be able to freestand
on the table, leaving your hands free for manipulating the
stone and torch and other tasks.
The rough is placed on the dop with temporary table upside
down and in contact with the flat on the dop. This puts the
pavilion side of the stone facing up. A second, small
diameter dop is placed in the fixture and lowered until it
contacts the pavilion side of the stone, pinning the stone
between it and the the crown side dop. I use a 1/16" flat
dop for the pinning dop, but one that was ground to a
moderate point might work even better.
It is often necessary to cut a small flat on the pavilion
side of the stone to create a level pad centered above the
culet for the pinning dop to push against and exert an
evenly distributed pressure. The rough is adjusted until it
is centered on the crown side dop, and then I mark the
contact point of the pinning dop on the pavilion side of
the stone with a fine point marker. This mark makes a
convenient alignment reference for when you're putting
things together hot.
I have an assortment of tweezers and modified pliers that
I use for picking up and manipulating stones of various
sizes and shapes when they are hot. During the cold run
I make sure the pair I plan to use can easily grasp and
release the particular piece to move it from the iron to
the dop, and to manipulate it. More and more I find myself
simply picking up and moving the stone with my fingers,
but there may be a bit of a Zen thing there, and your
tolerance will also vary with your callous pads and the
size of the stone. One thing I have learned is that it is
risky to heat a stone searing hot and that it is
unnecessary to do so to dop it with black wax. It doesn't
need to be hotter than the working temperature of the wax.
Using the iron for a preheater helps bring some control to
the process and insure excessive amounts of heat are not
applied to the stone. You could also homebrew a pretty
serviceable preheater from a light bulb, juice sized tin
can and a dimmer switch. It's easy enough to find the
appropriate setting on the iron by trial and effect with
a bit of wax for testing. I might be inspired to incorporate
a thermometer just for fun at some point when I run across
some appropriate electronic junk, or maybe a meat
My transfer fixture has spring loaded fingers that press
the dops into a v-groove. Once positioned, I clamp down
on the crown side dop so that it is immobilized. The
spring pushing against the pinning dop is adjusted so that
it can still be slid up and down in the v-groove with finger
pressure, but with enough friction that it will hold its
position and pinning force against the stone once it's slid
home. When everything is correctly adjusted and the stone
is properly pinned between the dops, the fixture can be
gently lifted, rotated and set back down on the table
inverted without the stone falling out or shifting position.
The stone and the crown side dop are given a final wipe with
a rag or paper towel moistened with isopropyl alcohol or
acetone to remove any skin oil or other contaminants just
prior to heating things up.
I determine when the rough and dop are up to heat and at the
working temperature of the wax by melting some of it on the
surfaces that are going to be brought together and bonded.
If the rough won't sit on the iron by itself so as to orient
the temporary table up and level, I place it on the iron
using a simple fixture made from one of several metal
rings fabricated from thin slices off copper and brass
tubing or pipe. Several of these have notches filed into
them here and there as needed to accommodate odd or
irregularly shaped rough. Once level, a chip of wax is
placed in the center of the temp table and the rough
incrementally brought up to working heat with the iron's
thermostat as previously described. When the wax on the
stone begins to melt and flow out across the temp table, I
fire up the torch.
A chip of wax is placed on the flat of the crown side dop,
or usually I just melt off some drops from a piece with
the torch, which harden as soon as they contact the still
cold dop. Once sufficient wax has been transferred to the
surface of the crown dop to cover it with a thin layer when
molten, it is then heated indirectly by applying the heat
from the torch to the body of the dop, rather than directly
at the wax. If you train the heat of the torch directly on
the wax for any appreciable time it goes flambeau. The
object is to melt the wax without getting it so hot as to
smoke and burn it. The wax melts when the dop reaches
working temperature. Wax that has been overheated and burnt
or fried does not bond properly.
Black wax will flow and follow a flame (heat) just like
solder. When the wax on the dop melts and flows, it will
readily 'wick' across and coat the entire flat of the dop
provided it is reasonably level and clean. Once the dop is
up to heat and the wax has reached a liquid state (with some
usually running down the side of the dop and off onto your
work surface), you can direct and 'tease' it into flowing
where you want it with heat from the torch applied to one
side of the dop or the other.
The wax will first bubble, and then boil vigorously and
start to get a little smoky just before it goes flambeau.
When I'm initially prepping and melting it onto the surface
of a dop with indirect heat, I use the appearance of small
bubbles (like simmering water) as an indicator it's time
back off with the torch.
BTW, have I mentioned that it's probably not a good idea to
do wax dopping over your significant other's good dining
At this point everything is up to heat with the dop surface
and temporary table both coated with a layer of wax molten
to a liquid state.
The stone is picked up from the iron with tweezers or
callused pinkies, inverted, and the temp table is placed
down against the flat of the dop. The pinning dop is then
lowered against the pavilion. As it nears contact, the
centering of the stone on the crown dop is tweeked as needed
so that the pinning dop is brought home on the position
mark created during the preparatory cold rehearsal.
Virtually all of the still molten wax will be displaced from
between the dop and the table when the stone is placed on
the crown side dop and the pinning dop is brought home. As
soon as clamping pressure is applied with the pinning dop
and the stone is securely positioned, the transfer fixture
is inverted so that the pavilion of the stone is now facing
down. Displaced wax which ran down the side of the crown
dop (now up) and away from the stone, now runs back down
the side of the dop towards the stone.
If everything is just right and you are having a good day, a
nice uniform, convex meniscus or filet of wax will form
between the circumference of the crown dop and the temp table
as the displaced wax flows back down to the stone. This filet
is desirable to help increase the surface area and strength
of the wax bond.
More often than not a properly formed filet requires a
little help. If there is enough wax to make the filet, but it
is unevenly distributed to one side or the other, the barer
side of the crown dop can be judiciously licked and heated
with the torch to lead the excess wax over from the thicker
side in conjunction with tilting the transfer fixture so as
to encourage migration of wax in the desired direction.
Often there is not enough wax to create a good filet, so
some more is applied, either by touching a cold piece of wax
against the dop to melt some on it, or by training the heat
on a piece of wax to melt and drip some off onto needy
areas. If there is enough wax to make the filet but the
stone is still hot enough that it slumps down and spreads
out across the temp table instead of forming a filet, invert
the fixture again to run the wax the other way. Sometimes
the fixture gets inverted and flipped over several times to
direct the still molten and flowing wax up and down, so
that it is manipulated with gravity into position and properly
distributed to create a nice filet when it thickens as it
cools and starts to harden. A smooth and nicely formed black
wax fillet is a thing of beauty, as it is a pretty reliable
indicator that all came together at adequate working
temperature, and that you have achieved a serviceable and
The working time that you have to go through the necessary
motions and how long things stay at the working temperature
of the wax is longer for larger stones and dops. With
larger projects you can work at a rather leisurely and
relaxed pace before things cool to the point that the wax
begins to harden. If things do begin to cool down before you
want them to, you can inject more calories by heating the
body of the crown side dop with the torch. It helps to have
the fixture oriented so that the stone is above the dop as
additional heat is applied to take advantage of convection
to help distribute the additional heat more uniformly.
A goal of this technique is to bring everything together and
get all of the positioning done while both the stone and dop
are both still slightly above or at the melting point of the
wax. If the temperature of the dop or stone falls below the
melting point of the wax and it begins hardening while you
are still moving them around relative to each other, the wax
bond is weakened and compromised. When that happens you get
a 'cold' bond, somewhat analogous to a 'cold' solder joint.
Similar to cold solder joints, cold bonds are prone to fail
during the faceting process when they are stressed.
Once everything is together and the filet is up to snuff,
the whole shebang is allowed to cool slowly to room
temperature without further disturbance. It's a good idea
to turn off the iron and torch as soon as you are finished
with them to help prevent accidents.
The black wax gets quite hard, but not so immediately after
cooling down to room temperature. There seems to be a
pronounced difference in the hardness and quality of the
black wax bond after a dop job has cured overnight. I think
this hardening process continues further with time, as wax
on stones I dopped a year or more ago seems *really* hard
I've never seen evidence of it through my own use, but I
have heard others talk of stone shifting problems with the
black wax. I assume due to softening from polishing
processes which cause significant heat build up in the
stone. I can see where that could be problematic for black
wax, but it works very serviceably for me with the water
lubricated cutting and oxide polishing processes I am
using on materials like quartz, beryl, garnet and
After cutting and polishing the pavilion the stone is ready
for dopping to the pavilion side dop and transfer.
An appropriate (largest available that fits) cone
dop is secured in the transfer fixture, which is placed on
the work surface so the cone is facing up. Chips of wax are
placed in the cone or it is dripped in by melting a larger
piece with the torch. If the pavilion is keel shaped rather
than conical, molten wax can be contained by a v dop by
temporarily damming its open ends with a wrap of tinfoil.
The pavilion is wiped with alcohol or acetone to remove any
skin oil or contaminants, and the crown side dop is placed
in the transfer fixture opposite and over the cone dop, with
a gap of half an inch or so separating the culet from the
cone dop. The tension is adjusted on the crown side dop so
that it rests snugly in the v of the transfer fixture, but
can still be slid up and down smoothly within the v.
Heat from torch is applied to the body of the cone dop until
the wax within is molten to a liquid state. The black wax
expands considerably when it melts and that effect is
observable when you melt the wax in the cone.
It is generally not necessary to fill the cone all the way
up to the lip, as most of the molten wax will be displaced
when the pavilion is slid home inside the cone. The excess
is used to create a filet between the circumference of the
cone dop and the stone as previously described for the
crown side dopping, so a filet's worth of excess volume
is really all you need. More doesn't really hurt anything
process wise, but you are again advised of the possible
danger involved in doing this over a good dining table
When the wax in the cone dop has liquefied, the gap between
it and the culet is reduced to nearly touching, and
convection is used to warm the culet. After ten seconds or
so warming, the culet is submerged to just below the
surface of the molten wax by sliding the crown side dop down
in its v groove slightly. A few more seconds for further
warming, and the stone is lowered into the wax a little
more. Then a few more seconds and lowered a little more,
repeating until the pavilion is home in the cone. It may be
necessary to lick the body of the cone dop with the torch at
intervals during the process of lowering the stone into it
to keep the wax liquid and at working temperature.
When the stone is home in the cone and the pavilion is
sufficiently warmed, the wax 'wicks' out onto the surface
of the stone at the interface with the wax bond, and a
small meniscus forms. The general idea is do things at a
rate which does not thermally shock the stone, but brings
the pavilion to sufficient heat so that the wax bonds to it
properly as you go.
Once there, the fixture is flipped over to recover wax
which has run down the outside of the body of the cone dop,
and this excess wax is manipulated using gravity and a
little directed heat if required to reinforce the perimeter
of the bond with a filet, as was previously done with the
crown side dop. You can add a little more wax if need be
by touching a piece to the dop and melting it on.
Everything is then allowed to cool to room temperature and
the wax to harden. Now you have a stone with dops stuck
to both ends. The assembly is removed from the transfer
fixture, and the crown dop is removed. This is done by
holding onto the pavilion side dop and orienting the
assembly so that the dops are horizontal. Heat from the
torch is then applied to the body of the crown side dop
until the wax bond securing it to the stone softens
sufficiently and the dop drops off on its own accord. The
dop will be pretty hot when it falls off, so you don't want
it to land on your bare foot or a surface which could be
marred by it. A recycled pot pie tin can be handy here.
Remaining wax adhering to the crown side can be readily
removed by scraping with a thumbnail while it is still warm.
I remove most of it because I don't like to contaminate my
laps with wax, and I usually need a clean girdle facet or
two to re-align the stone to the lap after transfer, as I
generally don't use the dop key on my Mark IV. I learned to
remove the remaining wax from the crown with my fingernail
while it is warm, instead of scraping it off with a knife
after it has cooled and hardened. I once caught the edge of
a temp table while doing that, and cleaved off a sizable
chunk that went right down through the girdle, ruining
all my work. I won't be doing that again.
Once the crown has been faceted and finished, it only
remains to part the pavilion side dop from the stone and
The dop is clamped in the transfer fixture, which is used
as a handle as heat from the torch is applied to the body of
the dop. The transfer fixture is held so that when the dop
reaches the melting point of the wax, the stone is free to
part company and fall away. Of course you do this just above
a soft surface that has been prepared to catch the stone
when it falls. I simply use a soft rag to catch the stone
when it parts company with the dop. Once off the dop, a
brief soaking submerged in a small container of isopropyl
alcohol or acetone softens and dissolves the remaining wax,
and the stone is wiped clean with a paper towel or soft rag.
I have never tried using shellac as a bonding agent with
the black wax. When the surfaces to be bonded are clean
and up to proper working temperature, the black wax
readily 'wicks' and clings to them. I have experimented
some with a preparatory wash made from wax dissolved in
alcohol or acetone, applied to the stone as a primer when cold.
However, the end result and quality of the bond seems the
same with or without this preparation.
In my experience, bringing the parts to be joined to the
proper temperature (a little above melting point of the wax)
and maintaining that working heat during manipulation is the
most critical aspect of getting good bonds with the black
wax. With a melting point of about 165 degrees F, that can
be accomplished at very reasonable stone temperatures with
black wax as soon as you've practiced a little with heat
Using the technique I've described, the heat from the torch
is applied to the stone indirectly by heating the dop and
not the stone directly. I don't find it at all difficult to
control and modulate the heat from propane or butane
torches, and I prefer working with 'hot' and concentrated
sources like that instead of alcohol lamps, which are
frequently associated with and used for wax dopping.
As mentioned earlier, I've found even a hardware store
variety propane torch like the kind that's used for
sweat soldering copper plumbing joints to be serviceable.
It's not so much a matter of the size of the torch as the
ability to adjust and control the flame and heat, and
a little practice with it that's important.
While I've run on describing the process I use with
black wax in detail, dopping with it is one of those
things that's more readily done than described. You'll often
hear wax dopping described as an art and something that's
difficult to do. That simply hasn't been my experience with
this wax. If it were of that nature I would be using some
other wax or general dopping technique.
I have only once had a black waxed stone break loose from
the dop. That happened early on, on my third stone, which
was first one I dopped on own at home without the
supervision of the instructor who introduced me to black wax.
I had a cold joint and found out about it as soon as I
started roughing out the stone.
There are a number other dopping waxes available and used
by faceters on gemstones, one of which is a
brown wax which seems to be preferred by a number of other
faceters I know through Tucson's Old Pueblo Lapidary Club.
That wax has a higher melting point than the black wax, and
the specific techniques I have observed other faceters
employ for dopping with brown wax vary significantly from
those I've described for black wax. In general, I see them
using it in a more viscous and plastic, rather than
liquefied state. Some of them tell me they particularly
prefer the brown wax for dopping smaller stones, and also
for polishing hard stones like sapphires with diamond,
where a fair amount of heat can be generated and transferred
to the stone.
I tend to work on the larger side with materials like
quartz, garnet, beryl and tourmaline which I cut and polish
using water lubricated processes. I have found black wax to
be easy to use and very serviceable and reliable for them.
Black wax works for me.
Perfect Transfer Index
Table of Contents