“I decided to start this site off with my most recent major project:
Resin casting a designer toy.
There are many reasons (one of which is that the photos turned out the best) however the most important one being how transformative it has been to my work. Hrm, that sounded too pretentious. Really what I mean is, that its something I’d never thought I would ever get to do but there, I did it. And now its a new skill. I’m by no means an expert but its somewhere not zero or wishing I could do this or that and that feeling rocks.”
Fair warning: This isn’t a tutorial as much as it is a journal of what I did. At the time I didn’t have the idea I’d post my process for someone to use, so bear with me. I will point out some mistakes, caveats and tricks I came across.
Meet “ded hed fred” a sculpture I came across trying to figure out how I could do fun bug-eyes and exaggerated proportions. I was thinking of a sort of Tim-Burtonesque Frankenstein’s monster and this is what I ended up with. I sculpted this in Sculpey Firm polymer clay. I wanted to try out the pre-baking process in a project and this is my first.
Pre-baking is baking a part of your model so its firm enough to hold and keeps finger prints off the back of your model. Its a bit of a long process but it takes a lot of the frustration away from sculpting in clay. Some people only bake part of the way so the clay is still soft and has some plasticizer in it, however I am quite rough when handling my models so I go all the way.
Wait, won’t that burn your clay? No, it shouldn’t really. The clay won’t burn as long as you don’t take it over the indicated temperature on the package! An oven thermometer is essential! Ovens are tricky! They lie!
Now, here is where I’ll list some mistakes I made and where you can catch yourself if you wind up here.
First off is the design of the sculpture. This particular sculpture has a few problem areas that needed addressing. The one word you will be hearing a lot when casting anything is “undercuts“. (Fig. 02 First picture, blue and pink circles)
Undercuts are over (or really under-hangs) that can trap bubbles and/or make it difficult to remove the piece from the mold. In this case bubbles were the enemy as I do not yet own a pressure pot or vacuum chamber. These areas in the image are where most of the bubbles ended up, they were relatively easy to clean, however every minute spent working on a model adds up when mass producing. All time I’d rather have spent painting, casting more models or starting on a new sculpture.
The second problem were are around the eyes. There are deep grooves (Fig. 02) where the bulging eyes meet the model, which should really have been filled in and made more shallow. Why? Well the first dozen casts are nearly perfect and the Smooth-On silicone is fantastic for capturing even thin little parts like that, however the problem is that its too good at capturing them and you get film-thin sheets of rubber that will eventually pull off the mold making it less and less accurate. I give this mold about ~8-10 more copies before I start to see a problem. Not a major problem as I still have the master and I can go back and fix this problem next run if I do one.
The third problem (Fig. 02 second picture) was a few inclusions that I left in the original model which taught me to be absolutely sure you want every detail in your final casting. That Oomooo is no joke and will take every detail texture or shine. Which is great when you want it.
Besides that, this is a pretty good first run. The only other gotcha is the back of the model. I chose to make it flat and use that side to base the mold, which causes a “cupping” effect unless you fill in extra, which causes an equally annoying “doming” effect on the part of the model requiring more cleanup i.e. time and work. A Dremel tool does make short work of that however, this plastic is easy to work with.
I used Smooth-Cast 300 since it was available and looked to suit my needs. I have some regrets about this as 300 has a pot life of about 3 minutes but it feels like 30 seconds. That leaves almost no time for getting bubbles out of tough areas or doing a beauty pour and becomes viscous very quickly. It also doesn’t seem to behave too well with pigment powders which I’ll touch on below.
My first casting was surprisingly bubble-free and I was quite happy with the results. However some of the castings did have small bubbles or seemed to have no bubbles but were actually cavities hidden by thin resin films. This however didn’t hurt the overall look of the models as the subject matter is due some roughing up.
I repaired some of the more obvious holes and inclusions, then purposefully carved the plastic in some places where the mold started to fail and lost a detail or two. The work continued on and everything went well. Then I started to mess around with some pigment powders I had lying around and things started to get interesting.
I added some of The Pink by Culture Hustle since I had bought the packs of their pigment powders last year, I also had Green annd I love it as much as The Pink so why not! The Pink needs some grinding to get the bigger bits out (really some alcohol would have broken the bits apart just fine) but the speckled effect is lovely.
Trying to mix pigment in white resin will always get you a lighter shade, which was quite lovely. I should really try Smooth-Cast 325 as its designed to take pigments and inclusions. But science called.
With the Green there was an issue with foaming that was quite bizarre.
I’m still not sure what the deal was. TONS of bubbles yet the front of the figure was fine. I theorize I might have added too much pigment but then I’m not sure what the critical mass was. I think I might have added equal parts to the B side (the resin) which might have been a bit much in hindsight. I’m sure I won’t need as much if I had used SC 325.
I painted these with Vallejo Black primer as its my go-to when painting miniatures. Then I went over with a series of acrylic inks and acrylic miniature paints. Next, I used some oil washes and finally a hard coat varnish.
This was a fantastic experience with a lot of thrills and chills. Nothing like casting copies of something you yourself sculpted, its a great feeling. I picked up most of my technique from Crafsman Steady Crafting on Youtube. Give him a watch!
If anyone is interested in purchasing one of these guys, my Etsy is up!
Thanks for reading, stay tuned for more!
