Sculpting issues and Moldmaking

Further Sculpting and re-sculpting has taken a bit longer than I would have liked but has been a learning curve. I knew from the outset that this would be the most difficult part of the project for me as sculpting really doesn’t come naturally. The hard part comes in deciding to 'destroy' parts that appear quite correct but need complete overhaul to really perfect them.

Of particular difficulty were the facial details, especially the mouth. As the photos above show, the mouth changed radically before the point of molding. I must have spent the best part of 2 days working on getting it right. The final mouth may still not be perfect but I felt the overall look (see below) of the sculpt was correct and further modification would have increased my frustration with it and likely affected the quality.

With the sculpt complete I began making the mold. Initially I had discussed making a fiberglass mold that would not require a silicon jacket. However, discussing the subject with Julia in the workshop, we decided it was best if the front was covered in silicon to ensure the slight undercuts and facial detail were preserved in the mold. In order to do this I created a clay wall around the outside of the sculpt and over the head (see below). The cut outs allow silicon to 'key' into the fiberglass jacket at the next stage.

Mixing up the silicon with Thixotropic and Accelerator I was able to apply a good coat to the front of the sculpt (above). Normally this process would be carried out with a layer of silicon (no additives) to ensure that air bubbles escape from the mix. I skipped this layer due to the lack of detail on the sculpt and my easily being able to see which areas were sufficiently covered before applying more silicon. 

I began the fiber glassing process by applying a layer of gel coat across the silicon and over the clay walls (above). This creates a solid layer that will secure the silicon in place during casting. Once tacky (after around 20mins) I began to lay up with fiber glass starting with the thin weave and building up to the thicker (below). All fiber glass was applied using standard polyester lay-up resin.

  

Once each layer of fiberglass has cured with the resin I added another (approx 3 times) to create a good wall thickness which will be necessary when prising oven the mold (applied fiber glass seen above).

 The back section of the mold presented problems due to its unusual shape. To make it easier to de-mold I split it into two with a wall down the middle (above). Before applying gel-coat I ensured that the exposed fiberglass on the front of the mold was well coated in beeswax and Macwax to act as a barrier between the two. 

Clay Sculpting

On Monday I fixed the body guide in place at the front of the armature and began building up clay (above left). Using various photographs of the Oscar award I was able to quickly build up the basic form of the upper part of the sculpt.  This really has been the part of this project I felt would challenge me and I have been surprised at the speed it has come together.

Today I continued to progress by getting tutor opinions as I made progress. The area at the back of the sculpt shows the amount of space taken up by the mechanism (below).

The face sculpt has been unusual as it is difficult to decipher from photographs as they all show different reflections surroundings and light pending. The large scare statues outside the awards venue are much more defined than the actual award which appears smoothed over. I am trying to a few more variations on the face before I am happy.

 
On Paul’s recommendation I took turn around photos which I can now use to measure and draw lines to better understand where the faults are in the sculpt (below).

Sculpting Base

In order to accurately sculpt the Oscar statuette so that it is suitable for molding, casting and eventual use on the top of the dispenser. By adding supporting walls around the mechanism and being attaching them square to the copy of the upper extension (below), I can accurately sculpt without risking damage to the final body.

One element I overlooked was including the correct top edge of the PEZ body to guide me in the sculpting of the forearms and sword positioning which I intend to blend in with the joining seam down the front of the PEZ body.  I will laser cut the front edge and affix it accurately on the sculpting board below. I should then be ready to start bulking out and sculpting in clay from next week.

Acrylic and Blue Foam Maquettes

Having modified the Rhino drawings to feature yet more minor changes to the mechanism design I decided I really needed to make an acrylic maquette (above). Although I have delayed using acrylic keeping the material costs in mind it has become necessary to test exactly how the minimal material will perform in terms of tolerances.

An idea that has crossed my mind before this point is making the entire PEZ clear to show the mechanism functioning internally as the dispenser is operated. I feel that the amount of work involved in keeping the joints clean and clear is far too great at this point in the project. I do however intend to keep this first acrylic maquette when displaying the finished piece to demonstrate the mechanism.

This acrylic maquette allowed me to test the upper mechanism extension which will fit within the sculpt (above). In order to ensure the mechanism was a solid as possible I reinforced the joints by using Tensol 70, as previously used in the making of my acrylic cases. 

On trying to place the mechanism into the body I head a cracking sound which turned out to be a 1mm overhang in the topping piece of acrylic (below). The overhang was left over from the standard PEZ drawings which I had overlooked when it came to adding the mechanism. I simply sanded the overhang back to meet the main 5mm body pieces and will fill then sand the top back before spraying.

For the first time within the body I was able to make the mechanism work (below). The addition of the upper extension along with strong Tensol joints seems to have made the dispensing action much smoother and defined than any of the styrene mock ups were. 

The thread holding the counter weights within the body broke once. Although this failure of the thread is uncommon I can't allow it to happen on the finished piece as replacing it will prove difficult if not impossible without damage. I will purchase a stronger thread intended for bigger fishing. At present the weights hang freely and thus can move freely within the body potentially causing further strain on the thread (below). To prevent this freedom to move I will incorporate two tubes in which the weight will be restricted to simply moving up and down as required.

Asking around amongst fellow students I was encouraged to decrease my proposed size of the sculpt. At first I was unsure and so was Paul. However upon reducing the size to approximately a third of the overall size somehow makes the sculpt size appropriate in relation to both the standard PEZ and the Oscar award itself. Printing a reduced size guide I was able to cut a rough blue foam guide to get a better understanding of how the sculpt will be formed and will sit in relation to the mechanism and body (below).

Roughly carving the form of the sculpt indicated to me that I need to add some sort of supporting walls either side of the mechanism to prevent the sculpt clashing once cast. Initially I was surprised at the size of the gap exposed at the back of the sculpt. The dimensions in relation to the standard PEZ are very close to being exact however there are obvious differences in the mechanism design which leave the back feeling more exposed (below right). I will discuss this with the tutors.

More Refinement and Begining to look at the Sculpting Process

 

I began today by de-molding a solid silicon grip piece which I poured yesterday again using left over silicon. This turned out well (above) and features much more defined grip lines as well as a greater number of them.

I spoke to Paul about the problem with the arm not returning due to friction. He suggested raising the level of the pivot to the top of the mechanism body to increase the incline of the thread from the arm. I was really quite surprised that this did the trick. Putting a piece of acrylic rob in place over the top of the mechanism body and threading over the top and down into the body to the weight gave extra leverage to pull the arm back to its start position even with the carriage at full height.
It's still a little rough though and I am starting to think I need to make an acrylic maquette simply to determine how much stronger it will be. 

The photo above shows the addition of a second weight to allow the arm to return to its start position. It is evident that the space in the lower part of the body will need to be designed to keep the weights apart as well as secure from swinging about and potentially causing damage to the tracks within the body. 

Having the mechanism parts drawn up on Rhino (below) allows me to work out exactly where the sculpt mounting will move to and therefore I am able to design the plate to which I need to sculpt. The shape of the joining part of the sculpt will have to be will considered as it has to allow the full movement of the mechanism without causing malfunction. Tomorrow I intend to define the sculpting plate and start drawing the parts to be laser cut. I need to make a mock top section of the dispenser to work the sculpt to.

 I am unsure about the best card type to use in the mechanism as the smoothness seems to vary the effectiveness of the mechanism however I can't be sure of this until I have an accurate acrylic version to work with. I hope to cut one tomorrow. I have sent off for a sample pack of cards from a company that Will recommended which should be here within a couple of days. (http://www.aubergineprint.co.uk)