[proj2] casting + molding: wall tile

0. Part Design

A modular wall tile pice with a pocket. The pocket became a problem when creating a CNC cut file – undercuts! In order to acheive the pocket option, I had to either create sectioned cut parts, or mill the same piece twice (front and back), or create a 4-step mold ( instead of 3-step mold as shown below). For the purpose of quick testing, I deleted the pocket.

1. Foam mold milling
1/2″ dia drill bit for roughing
1/4″ dia drill bit for finishing

Carefully sanded all surfaces, and applied gesso to seal porous foam surface. Lastly, I applied diluted soap solution as release agent.


2. Oomoo Pour
1:1 ratio between part a, part b
cures in 10 minutes

3. White plastic 305 Pour

1:1 ratio between part a, part b
cures in 10 minutes

next time: need to clamp the two molds together – the liquid solution kept seeping through. What I did on the second pour was that I waited couple minutes after the initial pour (to the seam line), and then poured the rest, and it worked out better.

What happened after I took out the casted part was that the oomoo mold at pour hole was too thin, and it  tore as I peeled the positive part away from the mold. Next time, the mold will need to be at least 3 mm thick to ensure flatness and firmness after the pour.


4. Expandable Flexible Foam

expands 15 times volume

Definitely need to clamp down the mold. I pressed down with  my hands but the pressure wasn’t enough (and uneven) to keep the foam from pushing away the two mold parts. I also took out the piece too fast and left a finger mark. But other surface area was smooth.

4.196 Special Problems in Architectural Design Complete Fabrications Nick Gelpi Mon-Fri, Jan 5-7, 10-11, 13-14, 18, 20-21, 24-25, 27-28, 01-04:00pm, 3-402/7-432studio, 1st mtg Wed 1/5 Pre-register on WebSIS and attend first class. No listeners Prereq: Permission of instructor ; Yr-1 MArch students who have completed 4.123 only Level: H 9 units Standard A - F Grading Can be repeated for credit Lab Fee: 150 A comprehensive introduction to methods of “making” explored through a wide range of brief but focused exercises. Skills = developing complex geometries from flat components; fine-tuning press fit construction, molding and casting, and making repeatable molds for customization. A two-part workshop, the first half will contextualize contemporary tools and techniques within the trajectories of historical case studies of building, combined with hands on familiarization of tools. The second half will implement the tools of our workshop in the context of Design. Working on group design build process for three MIT 150 FAST installations, students will test and influencing designs through the instrumentality of production. These hands-on design build projects are intended to produce reciprocity between skills and design, making more complete the problems of fabrication. Subject limited to year-one MArch students who have completed core-1 studio. Contact: Nick Gelpi, 9-224, 253-9415, -


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