Hobbies

HOBBIES, GEEKING, ART, CRAFT, EXPERIMENTS AND INSTRUCTABLES BY ME

Hints for a complete gourmet garden, on the cheap	Rustic woodware at no cost and easier than you thought	Colorful liqueur bottles
Pasta with funghi porcini (italian mushrooms)	Electric cappuccino stirrer from recycled stuff	Cold Porcelain
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1) COLD PORCELAIN

Brief history of porcelain

Porcelain is a kind of clay containing Kaolinite (Al₂Si₂O₅(OH)₄) . Objects are modeled with the paste which is then burned at high temperatures.
Originary from ancient China, it was imported to Europe around the XVI century. Later, in the XVIII century the European researchers Ehrenfried Walther von Tschirnhaus and Johann Friedrich Böttger could make porcelain by mixing clay with different minerals.
An excellent review on porcelain can be found at wikipedia.

Brief history of cold porcelain

Cold porcelain was born in Argentina as a cheap, non-toxic, easy-to-work-with alternative to porcelain, which does not require heating (i.e. it gets hard by exposition to fresh air).
Its main components are cornstarch and white glue, having also other low quantities of oils and glycerol which give its texture. Because this are biodegradable materials, lemmon juice and sodium benzoate are some times used to prevent the growth of bacteria and funghi.
It can be made at home (see below for recipes) very easily, and it can be used for small projects. However, it is disolved by heat or water, so don't expect to start making cups with it!

An eppendorf rack made with cold porcelain and painted with coomasie blue reagent. Click here for more photos

My recipe for making the paste

1) Put:
- 3/4 cup of white glue
- 1/3 cup of water
- 2 teaspoons of baby's oil
- 2 teaspoons of glycerine (i.e. glycerol)
in a pan made of teflon or some other material designed to avoid food from sticking to it.

Heat this solution with low fire while stirring, until the liquid components mix. This may take 10 minutes. Stirring is very important to avoid the formation of local aggregates due to overcooking.

2) Little by little, add 1 cup of cornstarch to the liquids mix while stirring gently but continuosuly and heating with low fire.
Note 1: Basically, this step will end when the initial liquid cream starts to become a paste, i.e. it is starting to get solid.
Note 2: However, if there is too much water then this process will be slow. In this case you can add more cornstarch, baby's oil and glycerine in small amounts, mix, and check again.
Note 3: In the rare case that the opposite occurs (that is, as soon as you added the cornstarch it seems like there is too little liquid) then add a bit of glue, baby's oil and glycerol, you may even add just a bit of water.
Note 4: If at some point you feel that the mix is sticking to the pan where both surfaces make contact, but the mix is still clearly a liquid, then turn off the fire, mix trying to redisolve the parts sticked to the pan, stir, and proceed with next step.

3) When the paste is starting to form (or in case you went through note 4!), turn off the fire and continue stiring, thus allowing the mix to loose heat homogenously. When it's at room temperature, if it seems like it is too liquid then you can add some cornstarch and re-mix (but be sure you don't add too much!!). Finally, when the paste is almost ready, apply some (rather a good amount!) baby's oil to your hands, take the paste and mix thoroughly with your hands, adding cornstarch if you think it's necesary.

4) When you have a consistent and homogeneous mass of paste, which is malleable and doesn't leak liquid, put the paste in an hermetic bag and store in a fresh, dark, dry place. Next day will be ready to use.

5) (using) Before starting to work with cold porcelain you may find it useful to put some baby's oil in your hands, so as to keep the paste from sticking to your skin. After you finish your work, let the paste dry on a fresh place.