by Yun-Han LinIn recent years, cement handicrafts have become popular. The two works in this article feature are maker-friendly for beginners to learn different forms of cement and make their own works based on their likings.
Concrete mix made up of Portland cement and gravel is the most common type of cement in general use. Larger pebble size has good structural integrity, while thinner ones feature smooth surfaces. The Lotos Concrete Pour we used is known for its fine aggregate as well as cement additives such as defoamer and rapid-setting additive. These chemicals allow cement to have better flow rates and to harden more quickly, which takes only 1 ~ 1.5 hours before demolding.
For cement to take shape, it must be poured into molds. Here are some common materials and steps you may find useful:
1.Silicone Mold: A useful tool if you are only using a small amount of cement. After finishing the first sample, you can make copies by using a silicone mold. The cost for this mold is relatively high though, and you need to come up with the very first sample before you start mass-producing.Sample:https://www.youtube.com/watch?v=oxyS0ZeHTyk
2.RegularContainer: Plastic cups, paper cups, paper bowls, etc. with different sizes are also good options for making the inner and outer molds. Yet, the shape and size of your work is decided by the container you adopt.Sample：https://www.youtube.com/watch?v=uSSp3X07Vls
3.Thick Plastic Sheet / Acrylic Sheet: Cut the plastic sheets into the shape according to your design. Then piece them together using tapes or glue. Plastic sheets can take much time and effort but they have been proved successful on many geometric pots.Sample：https://www.youtube.com/watch?v=lWk9mDhZAVk
4.Plastic Bag: Commonly used in making coasters. It is time-saving and easy to make, and also one of the materials we used in this demonstration.
5.Form Sheet / Styrofoam Sheet: 1mm foam sheets are bendable, so they can be turned into molds in different shapes and even form some hollow space. Hot glue canbe applied to the bottom plate to hold the parts together. The flexibility of a foam sheet is the reason we choose it to make demonstration this time. (Note: The idea of using foam sheets comes from a Maker’s space- Nicon.).
A work for beginners, and the production takes about 20 minutes. The only step that may go wrong is when you pour the cement into zipper storage bag. Make sure the cement does not exceed the marking line on the bag, or the cement could seep between the sealing zipper, and the bag will not be closed airtight as a result. In that case, you will have to redo everything all over again. In addition, to make plates of any other kinds, the amount of cement should be about 200~250g.
To facilitate creation, here is our template with simple outline to assist your drawing (size: 110 x 110 mm). To save more time, you can even laser-cut templates in intended shape beforehand.It is recommended that the pattern is not designed with too many sharp angles or complicated curves, which could make it difficult to bend the foam sheets. Also, the base of the plate is relatively fragile, it is crucial to wait for 1.5 hours for hardening before you demold!The following are the works by the 7th graders of Taoyuan Municipal Guanyin High School: