Work in Progress: A Dragon's Eyes (Assembly)

It's hard to believe that I've been at this for over a month now.  I'm sure Dean and Adrienne think it's taking too long, but for me the time has flown by.  I don't get to spend time on this project every day because of work and other commitments.  The time I do have for it I spend mostly watching resin cure (it's kind of like watching paint dry but slower).  Each time I cast a resin part almost 24 hours pass before I can do anything else with it.  I brought the dragon home last week (his name is Zippy it turns out) so I could work on it in my workshop instead of having to take several trips to Dean's house. 

Knowing now how I was going to make the eyes and needing a new, clean mold to do it I mixed up a batch of oogru and set to work.  Previously I had taken a single mold of the entire face so I could have a copy from which to work.  This time I did each eye individually since during final assembly that is all on which I would be working.  I took care to work as much oogru into the fine details around the eyes as possible using a popsicle stick, and I came back with a second layer after the first had cured to thicken and reinforce the mold a bit more.

First layer of the new mold.  Even after it's cured oogru will bond solidly
 to new layers of oogru.  It doesn't bond to much else however which makes
 it so good for mold making.

Once I had a satisfactory pair of molds I began cutting out the eyes from the original sculpture with a rotary tool.  This turned out to be harder than I expected.  The reproduction on which I'd practiced was less than 1/8" thick at its thickest point.  The original was much thicker.  I absolutely didn't want to make a mistake at this stage, so I took well over an hour for each eye to get them right. 

Dean and I had discussed making the eyes with a clear, slit pupil and having the rest of the eye translucent white.  I took a pair of similarly sized lenses (from my original experiments with the jeweler's resin) and marked them with some measurements I took from the molds I'd just finished.  I used my band saw to cut roughly identical oblong shapes and then sanded them with an emery board until they were almost exactly the same size and shape I wanted.  I placed one in a mold to confirm my measurements, and I realized I had a problem.  The little piece of resin wouldn't stand on its own in the mold.  I would have to prop it with something while the resin around it cured, and that simply wasn't an option in the tight space inside the dragon's head.

The pupil component glued into a mold.
I marked the end of the piece with a
marker to make it more visible to the camera.

I decided to resolve this issue by "gluing" the piece to the mold with some liquid resin.  I put the two molds face-up on a table, propped the pupil pieces in the molds using popsicle sticks, and mixed up a small batch of resin.  I became concerned that if I tried making the translucent resin as I had previously (by stirring in bubbles while the resin slowly cured) I wouldn't be able to get the exact density of bubbles in later batches resulting in visibly distinct layers when I poured the final section of the eye.  I opted to use just a small amount of clear resin to glue the pupil component in place.

A day later the pupils were more or less secured in the molds.  The fresh resin would hold them in place so long as I wasn't too rough with the mold.  If I accidentally "unmolded" them I'd probably have to start all over.   I used modeler's clay to create a wall around the eye hole on the inside of Zippy's head as I had done previously taking care to keep the flesh-colored polymer clay well back from the edge of the hole so it wouldn't be visible and wouldn't interfere with the resin bonding to the original sculpture.  I carefully placed the eye mold back on the face and secured it with a pair of rubber bands.  I laid the sculpture down and propped it with books so the eye on which I'd be working was level with the floor.

The left eye mold strapped on with rubber
bands.  Notice how much thicker it is than
in the image above.

The inside of Zippy's head is a tight space around a sharp corner.  It's impossible to see directly into the area in which I was working, so I used a small night-vision security camera I just happened to have laying around (something else in my weird-ass crap box).  I placed the camera inside the cavity facing the inside of the eye on which I was working.  This allowed me to observe indirectly what was going on inside the head.  As soon as the camera was in place I noticed that I'd created a rather large well with the mold and the modeler's clay.  I had been previously mixing jeweler's resin in 5ml batches, and it occurred to me that I would need a somewhat larger amount to fill the space I'd created.  Alternatively I could make two separate batches and pour each individually.

Recall that my original plan (back in the very beginning) had been to create a complex eye with a cornea, iris, and retina.  I had liked the effect, but the implementation in its original form was too difficult.  Looking into the large void I had to fill I realized that I could make the complex eye in a series of pours rather than a series of parts.  I mixed up a batch of clear jeweler's resin and drew it into a syringe.  I plugged the end of the syringe and pulled back the plunger creating a partial vacuum inside.  All of the bubbles suspended in the mix (and there were many more than I realized) swelled like balloons and rose slowly to the top of the fluid.  I reached the syringe into the dragon's head and watched on my monitor as I slowly squirted the clear resin into the space around the pupil component that stood erect in the center.  I took extreme care not to get any resin on the flat top of the pupil, and I stopped pouring when the fluid level reached the rim of the eye all the way around.

This is the camera set-up I used.  You can see the outline of the pupil component on the monitor.  What's harder to see is the
 syringe hovering over the well that I'm using to drip resin in.

The next night I mixed up another batch of resin this time with bubbles.  I've discovered that if I wait an hour after the initial mixing the viscosity of the resin increases considerably.  This makes it easier to incorporate smaller, more uniform bubbles that don't float to the surface.  Once again I used the security camera like a laparoscopic surgery camera inside the dragon's head, and once again I slowly poured the resin into the well this time stopping before the fluid level over-topped the pupil component.  A day later I stood the sculpture up and unmolded the new eye.  I was actually surprised at the result.  Even without polish the eye had a nice three-dimensional appearance that made it look alive.

Four phases of the build (left to right): The original eye, unmodified; The eye, cut out (notice the thickness of the resin at the front of the socket); The new eye fresh out of the mold;  The new eye, all polished up.

I repeated the entire process with the remaining eye using a single drop of the fresh, clear resin to polish the eye I'd just finished.  This time positioning the sculpture to get the eye level was much more difficult however because the dragon's head is turned slightly, but when the two layers were complete the result was no less impressive.  To be completely honest I wasn't expecting it to turn out as well as it did.

I lit the eye with an ultraviolet LED just to see how it looks.  For some reason the UV light
 reacts strangely with my camera making it look like a bad special effect from the original Dune
 movie.  The sculpture here is positioned to let the resin in the right eye cure.

For those keeping score: it took a day to cast the lenses out of which I cut the pupil components, a day to "glue" the pupils into the molds, a day to pour the left cornea, another day to pour the left iris, a day to pour the right cornea and polish the left cornea, a day to pour the right iris, and a day to polish the right cornea.  In all a week of pouring components after all the experiments I'd done to this point.

Almost done!  When next I post on this subject it will be about the instillation of the lights and moving Zippy to his final home.  Since that might take a couple of weeks expect that next week's post may be about a different subject entirely.