Hi and thanks for visiting our blog! I'm Eby and today I'm gonna be walking you through how we made a flexible mold for our concrete sinks!! It was actually quite a long process (so this post may be a little longer than usual) but it gave us a good taste of working together before we're in each other's company 24/7!
If you haven't checked out the rest of our website yet, part of our project scope is building a filtered water distribution station in the village of Don Kang, Thailand. Our distribution station will be mostly a brick structure, but to allow for greater customization, we decided to create a custom, reusable mold to cast concrete sinks. This approach allowed us to fully design our sinks and allow for easy placement and removal of bottles while filling water.
We designed our sinks using a modeling software and selected urethane rubber (which comes in liquid form) as our mold material due to its durability and ability to be reused. We decided to create the forms for the mold using wood and got to work!
We first assembled a master copy of the sink from wood. This process took a few days, lots of wood caulk, and quite a bit of sanding, but at the end of the process, we were satisfied with our final product!
After we made a master copy of the sink, we made a box to place the master copy in and confine the rubber mold material. After we figured out a way to brace the master inside of the box, we began the process of pouring the mold.
We used a liquid urethane rubber as our mold material, so to ensure that the rubber would not bind to the wood, we sealed the wood with a wax product.
After the sealant dried, we sealed remaining gaps or irregularities with a non-reactive clay, to create a smoother surface for the mold to reflect.
We then put together the master and mold box and began pouring. As a last minute touch, we also added a small longhorn impression with clay to the sink!
The rubber material had a fairly short pot life, so we got right to pouring. Unfortunately we forgot to spray the master and box surfaces with a mold release agent, but we luckily didn't have much trouble removing the hardened mold from the wooden box!
For a first try, we were pleased with how our mold turned out! There was some somewhat severe separation on one edge of the mold, however, but after trying several different fixes, we used roofing cement to seal the crack.
We were luckily able to use the mold to do a test concrete pour using our designed concrete mix and our little sink came out okay! We hope this practice will come in handy in country when we're pouring these sinks every few days!
On a somewhat unrelated but exciting note, 8/9 of our student team is en route to Southeast Asia! I'm currently writing this post as our plane is taking off on our trip to Singapore, where we'll be exploring for a few days before we reach Bangkok on May 23! Patrick and David will be joining us in Bangkok, where we'll meet with Mahidol University students before heading to Don Kang. Thank you so much for your continued support, we'll be blogging through the trip so be sure to stay tuned and follow us on Instagram: @pucthailand2017 and on our Facebook page: Facebook.com/pucthailand
P.S. Patrick is graduating this week! Congrats Pat, you're an invaluable part of this project and we're so excited for and proud of you!!