“Keep my gloves dirty but my hands clean.”
Jidenna, Classic Man
So I’ve been pretty quiet the last few weeks, and here’s why: I’m a senior in the ID program at Mass Art, and as such, I got a chance to participate in the IDSA Merit Award presentations; basically a summation of your entire life in design delivered in a 7 minute presentation. 10 presenters go head to head at the school level and whomever wins goes on to compete at the regional conference. I was very honored to be chosen to represent Mass Art (against a field of some of the best designers and people I’ve ever had the pleasure of working with) at the 2015 Northeast IDSA Regional Conference, where I was awarded the runner-up spot, which they usually don’t give out, but apparently it was so close they couldn’t pick just one winner. So that was pretty awesome.
As you might be able to guess, the process of putting together this presentation, practicing it and then delivering it, while simultaneously getting my portfolio squared away for the job hunt and also doing all of my classwork was all pretty stressful, and I’ve only had so much time to devote to the development of the Coconest, BUT, what I have been able to do is SUPER exciting.
First, after buying all of the materials and tools and getting the parts printed, I set about making the prototype.
First I coated the parts in a resin to fill in some of the build lines and get a cleaner pull from the mold. Because the models were on the larger side, they had to print in 2 parts, so I had to epoxy them together after the fact and sand the part line. Still beats carving it all out by hand though.
Next I built mold boxes out of acrylic and built up a layer of clay around the base of the print for a two-part mold. Hosed everything down with mold release and mixed up my resin. I used some stuff called Task 11 from Smooth-on, which makes a very nice semi-rigid plastic, but what they didn’t tell me was the the Part B component has a VERY thick layer of sediment in the bottom that is nearly impossible to fully incorporate with the rest of the material… As a result, one of my molds basically looks like shit and the other one is about 90% decent, but only because I used a hand-blender to mix the solution before adding the hardener and EVEN THEN it didn’t 100% incorporate. Reynolds didn’t warn me about this at all, so I may try and get my money back. Every bit counts.
Anyway, after the resin was poured, I threw the whole thing in my rigged-up pressure chamber made from a Harbor Freight pressure pot and a few extra fittings. I cast at 60lb PSI for 16 hours.
Out comes the master part, the mold gets a quick rinse, and then it goes back in for part 2. Unfortunately I didn’t spray mold release on the bottom of the part and so it was basically impossible to get the master out in one piece on the second try — just too much surface area holding on and not enough leverage to pull the two apart. Ah well. At least the mold came out okay!
Both parts of the mold go in to the oven for an additional 16 hours at 150 degrees for a post-cure. This makes the plastic food-safe and improves the rigidity and memory of the material .
To save money, I used the pressure pot as a convertible vacuum chamber. Basically I built a lid out of 1/2 inch acrylic cut-off from Altec Plastics, a vacuum gauge and a few brass fittings, then just stuck it on top and used the gasket from the pressure pot to make the seal. I’m using Smooth-Sil 940, a food-grade silicone with a relatively high durometer and a really unfortunate pink color.
After mixing it for about 3 minutes, I degassed it in the chamber at about a 25-30 inch vacuum for 3 minutes and then poured it into the mold.
Because of the thin walls of the silicone part, I’m using a technique called a “squish mold.” Basically, you can’t just pour a mold like this because the liquid silicone won’t flow through the mold cavity. You can use a pneumatic injector, but they’re very expensive. So instead you pour silicone into one half of the cavity and then put the other half in, causing the silicone to fill the whole cavity and leak out the sides. It’s messy as hell, but effective.
The part fresh out of the mold. The edges are ugly because of the flashing caused by the spill-over from the process, and those gross wart looking things are imperfections in the mold because of the aforementioned mixing issues with the resin, but otherwise it’s totally functional.
The completed prototype (still in need of some cleaning up). The pink color definitely attracted some weird associations but it works! Huzzah!
The next step is to post-cure the silicone and then get to testing the functionality, first by myself, then with users who are less inclined to give positive feedback. Then I’ll take what I get, change what I need to and move forward. Things are picking up speed!
Until next time, hustle hard.