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Lost Wax in the Divergent and Convergent Modes

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Lost-Wax Bronze castingin the Divergent and Convergent Mode


            Iwill be discussing two kinds of sculpting, lost-wax bronze casting and theprocess of clay sculpting, and how they converge and diverge from one another.  I will include a photograph of thebronze sculptures.   However,I do not have a copy of the clay nude female sculpture to which I will bereferring.  It would have been neatto have such a picture to show the difference in the sculpture mediums.

The first thingyou need to do in lost-wax bronze casting sculpting is to make a sheet ofwax.  Usually a crock-pot is neededto melt the wax.  The lid is leftopen during the melting process to prevent the possible eruptions of the wax underpressure, a risk with the lid on. Another reason it is open is because the wax also needs to be stirred tolet out the oxygen.  Once the waxis melted in the crock-pot, it can be poured into a premade plaster of Parissheet mold that is watered down with a damp cloth to prevent the wax fromsticking to a damp cloth too.  In only a few minutes time, the wax is ready to be handled.  The damp cloth that prevents the waxfrom sticking to the cloth is lifted out of the plaster of Paris.   We now have a sheet of wax to work with, thin enough to beworked with by the natural heat of my hands.  

            Theidea is the most important aspect of the sculpture.  The idea comes to the sculptor spontaneously or contrivedthe product of purposeful thought.  Most of my sculptures were contrived by memories of my childhood.  I thought long and hard about mysculptures and came up with the most moving representations I could thinkof.  The first set of sculptures in(exhibit A) shown of my younger bother and me sitting together on the stoop,crying about-facing the first day of classes without new clothes.  All four of my brothers got new clothesand I did not for no apparent reason.  My younger bother wascomforting me.   I was tryingto depict a child neglected.  I wasresolved that this would never happen in my family when I become a parent.   It is a repeated scene in myhead.   This sculpture is asoothing and healing scene to sculpt, firming and strengthening my resolve.    

            SinceI have come up with an idea for sculpting I can begin.   Once the wax is poured and cooledto a workable temperature, I can start.  One piece from the sheet of wax must be cut large enough for eachsculpture.  I will need to cut twobecause I am making two individual sculptures. 

            Thetools needed for these sculptures are all hand-made from welding rods cut with theirends pounded down to serve as knives for carving and molding. Sculptors aretaught to make their own tools.  A Bunsenburner is also needed to heat the tools for sculpting.  It is a small flamed heating tool with flammableliquid inside a chamber out of glass with a flame on a wick protruding from thetop of the burner.  This wick islit with a match or lighter.  Theends of the tools are then heated with this burner, and will be used to carveand sculpt the wax by melting certain areas of the figure. 

            Thetwo pieces from the sheet of wax are just molded into ball shapes by the warmthof my hands.  Once the ball shapeshave been formed I can begin using my handmade tools to carve out thesculpture. I choose to start with the shape of a ball because the figures aregoing to be sitting down.  The sizeof the ball is dependent on the size of the figures that I want to create.  I make two separate ball-shaped piecesof wax from which to begin carving out my figures.

            Manyadjustments can be made along the way as I carve and mold the wax to suit theneeds of the sculpture.  Thehandmade carving knife is heated from the lit burner and used to assist incutting and carving the wax.  Ibegin with the head of the figure and work my way down to the feet of thesculpture. This carving and molding process may take many days and a lot ofpatience.  The heated handmadetools help to smooth the wax by melting it in addition to cutting and carvingthe wax.   

            Iwanted to evoke strong emotions from my figurine, so I carved and moldedgestures into the sculpture; one figure has a hand holding up a heavy head toexpress sadness or crying.  Thesecond figure in demonstrating togetherness with the first sculpture, wraps anarm around the sad figurine to show comforting, while remaining separate. 

            Oncethe sculptures are completed the next phase is to make and add what are calledspru’s and vents on the sculpture with wax.  They are essentially wax sticks attached to the sculpture toallow the venting of pent-up gases that naturally occur during the process ofcasting. These wax sticks are attached to all areas of the sculpture where anygases likely to get caught-up. Then the sculpture is mounted to a square piece of cardboard that will becompletely burned, and in fact disappear in the Kiln.  All the wax spurs and vents will be attached to thecardboard as well, with the sculpture positioned upside down.  This upside down position is used in anticipationof the pouring of the molten bronze into the mold as it is made into a bronzesculpture. 

            Thenext step in this process is to make a plaster of Paris mold for the sculpture.   I will put the sculpture on the cardboard and then into acardboard container like a milk carton that will hold all the liquid from theplaster of Paris. Within twenty-four hours it will have hardened into a mold.

            Thenext step is the kiln.  The plasterof Paris mold with the wax sculpture within it will be fired (heated) in thekiln.  This kiln will heat theplaster of Paris mold so that the wax will be melted and evaporated away andall the cardboard will have burned away as well, leaving just the plaster ofParis mold.

Once the mold ismade after the kiln-firing phase, it is time to melt down the bronze ingots thatwill form the actual figurine into a pot, from which the bronze will be pouredthe bronze into the plaster of Paris mold.  The plaster of Paris can withstand this high temperaturefrom the melted bronze ingots.  Themolds are then poured and set aside to cool and harden into a sculpture.

The bronze coolsand hardens in about twenty-four hours. Then the plaster of Paris can be removed from the sculpture by cracking it.  The plaster of Paris will fall awayfrom the sculpture.    It usually comes off the sculptureeasily without too much trouble.

            Oncethe plaster of Paris is removed I have a bronze sculpture but that bronzesculpture now has bronze versions of the spru’s and vents, mentionedbefore.  They must be removed fromthe figurines.  Usually they comeright off with a single cut from a metal saw.  These vents are usually pretty narrow and do not disrupt thesurface of the sculpture.  Anyuneven areas are smoothed by diamond cut burrs, which are somewhat like dentaldrills, but designed to finish metal sculptures flawlessly. This is the processthat is called evolving the bronze sculpture.   

              In contrast, the evolution of a clay sculpturebegins with an idea and a model. The idea and model can come in many different forms.  I will focus on the idea of a humanmodel, in particular, a female nude model.  This female nude model is five feet six inches tall andweights about 130 lbs.  Her figure hasvery pleasant feminine lines making the challenge of sculpting her gratifyingand rewarding.  In other words,there are a lot of wonderful qualities in this woman to work with whensculpting her body. 

            BeforeI can begin sculpting her body, I must measure every inch of her body in orderto use the exact dimensions to achieve a lifelike quality in the finishedproduct.  These dimensions ormeasurements are key to a proper armature, a series of welded metal rods, whichessentially provides the skeleton for the figure. 

            Duringthis process, the armature will be constructed upon on a man made platform withwheels for mobility.  The armatureis usually made of steel piping that is hand-welded together to meet thedimensions of the measurements previously taken.  As noted, the armature will look something like a skeleton,but not an anatomical skeleton.  Itwill have a neck, shoulders, torso, hips, legs and feet.  However, it will need a different kindof rib cage that is made of a separate and different kind of material.  The reason for this is mostly to makethe actual work project less demanding. Try to imagine welding each rib in the rib cage!  This would be a large undertaking whenthere are simpler methods that will do the same job effectively and efficiently.The main skeleton must be strong enough to withstand the weight of the clay andother materials used to make the sculpture. 

            Next,masking tape, crumbled-up newspaper, Styrofoam, and anything that I could find (includingthe trusty duct tape) are employed to help refine the armature so that it increasinglyresembles the figure I am about to begin sculpting with clay.  Because of cost, I used the lessexpensive brown colored clay, as did the rest of my class, in sculpting thiswoman.  I began by applying theclay to my armature generously to begin the evolutionary process of thesculpting.  First, it looked like awork by Degas with depressions or hole-like impressions everywhere giving thesculpture a very textured feel. This was not what I was trying to create.  I was rather trying to sculpt realism.  I wanted to sculpt realism because Iliked the figure I was sculpting and wanted to see if I could capture thefigure accurately in the evolutionary moment of this time in my life.

            Ineeded to use calipers to measure and re-measure portions of her body to getthe depiction correct.  Once I wasable to capture the essence of her total being I began to become creative in adifferent way.  For instance, Imade an incision in her right arm and cut through the armature where her elbowmet her torso, leaving the observer to fill in the blanks where I had removed apart of her arm. 

            Anothercreative decision I made with this sculpture was to remove her head and leaveher neck armature exposed.  Iwanted the observer’s imagination to complete the aesthetic impact of themissing piece.  I wanted to createthe illusion of art from another era, perhaps similar to ancient Greek or Romansculptures that were left headless either on purpose or were damaged by time orvandalism.   

            Iwasn’t able to complete this sculpture in bronze but I did complete it inclay.  I was very satisfied with itand wanted to move on to the next step which, would have been to cast it inplaster, make a mold then use the mold, and then cast her into bronze.  I ran out of time.

            Notunlike evolution, sculpting is an evolutionary series of processes or stepsthat are taken to bring you somewhere, and sometimes it is unending.  I could have tweaked this sculptureforever while it was in its clay phase, but I was comfortable enough with theplace I was at to stop and move onto the next phase.  In Paul Grobstein’s “Cezanne and Beyond” series he discussedthe evolution of Cezanne’s art from realism to abstract.  That theory can be applied to myevolutionary process with my sculpture, particularly when I was finishing upthe sculpture and made those creative changes to her body.  Those creative changes, I would argue,were evolutionary within me as a budding sculptor. 

            Inconclusion, we as human beings are always evolving and my two examples of humanisticand artistically. 

            Thejoy of capturing my subjects as I see them, the subjects converged.  Both vehicles of my ideas converged, asthe sculptor needs to know the anatomy of the sculpture in order to convergeappropriately.   An awarenessof the sculptures is important for the figures to be captured in the threedimensional frame of convergence. 

            Oneof the joys, of working in detail on small figurines with wax vs. the pleasuresof three-dimensional power of the larger sculpture for which I will useclay.  Although it can be used toform smaller figures, it can be used to create works of art that is momentousand are more useful for the monumental figurine in bronze.

            Thedifferent texture of the clay is so different from the texture of the wax that thewax is divergent from sculpting clay sculptures.  Clay is smooth to the touch and not sticky whereas wax issticky to the touch and you get used to the texture of wax whilesculpting.  Clay is wet andslippery to the touch because you always need to keep the clay moist.  If the clay dries it will crack andfall apart before completing the sculpture.  You do not want this to happen before completing yoursculpture. 

            Thejoy of working in detail on three-dimensional small figurines with wax vs. thepleasures of three-dimensionality powerfully works for the larger pieces forwhich clay is used.  Clay, althoughit can be used to create small figurines as well is more monumental andDivergent from wax.

            Waxhardens quickly and you must always have it in your hands to keep it malleablewhich is convergent with Clay that must always be kept moist with a waterspritzer. 

            Thedifferent mediums keep the mode divergent.   Convergence happens when wax and clay are similar insculpting techniques.  Thedifferent tempo in the dynamics of the artistic process with lost wax and thealmost timeless process with clay sculpture.  The 3-dimensional space image is important as well as therest of the sculpture.  Yet someelements are the same making it both divergently and conversional.

            Thewax sculpture must be worked with in a controlled temperature environment likeair conditioning and ventilation whereas the clay sculpture can be worked within any temperature as long as the sculpture is kept damp.  This is an example of both convergenceand divergence from the sculpture. 

            Ona personal level, wax does not feel right for the abstract even thought manysculptors use this methods for the abstract.  I felt that clay was a great medium for the abstract and isused for many sculptors.  I wouldconsider my methods divergent with regards to the abstract.

            Whenwax becomes bronze, often it is patina, but not necessarily.  When clay becomes bronze, usually notbecause of cost.   Size oftendictates the amount of Patina used, Patina is typically used for smallersculptures such as those used in was sculpting.  I used black Patina, which is a coloring of the surface ofthe bronze to conceal the natural aging to green.  Some sculptors choose green as their patina to start thenatural process.  I wanted asilhouette looking figurine. Patina is hard to come by and is typically used is small amounts whichis why a lost-wax sculpture is perfect for a patina sculpture. 

            Claysculptures when bronzed, is difficult to Patina because it requires a greatdeal of liquid patina to be spread throughout the sculpture but notimpossible.  It is more costeffective to let a large life size sculpture age on its own into the naturalcolor of green. This is an example of a divergent method of sculpting.

Once again, inconclusion, divergent and convergent sculpting is a unique look at sculpting inthe evolutionary process.  Theevolving sculpture is a unique way to look at the evolutionary process from adifferent medium.  I found bronzesculpting to be inviting instead of exclusive.  My professor, Professor DeLonghi died during my semester atMount Holyoke College and ended my career in sculpting.  I was never able to find anothersculpting professor as great as him to continue with sculpting.  He was one of my mentors and I hopeanother student has to go through this transition of Professors.  He was a truly gifted professor andtaught me a great deal about art and sculpting.  He made me the sculptor that I am and now Bryn Mawr has mademe a writer.

I have learned somuch in my years of education at both Bryn Mawr and Mount Holyoke that I cannotbe more grateful.