MindFad's Gallery: making molds part 2

Monday, September 3, 2012

making molds part 2

TUTORIAL: Mould Making, part 2

Now it's time to show part 2 of this tutorial.

OK, we were waiting the silicone to cure. Now, 24 (or more) hours later, it's done, so, you must remove the plasticine and wash with water.Then, I've turned the hemi-molds upside down and built the LEGO boxes.

Before finishing the boxes, use the vaseline or lubricant and apply a thin layer over your bit and mold. This is made to avoid the uncured silicone to stick to the cured silicone.

Then I prepared the mix and repeated the process.

Then again, wait another 24 hours. And voilà!

Now it was time to arrange and fix the molds. Cut the flashs, cut every bit own mold, and the most important, cut holes to pour the resin.

Before anything else, measure how much resin you will use, with water. With another syringe pour water to know exactly how much resin you need. Always add half a ml. Anyways, if you add less than the amount you need, you can add resin later, after cured. That's a very useful property (and I'll explain later what you can do with this!)

It's very important to let dry this mould (the one you used to measute with water) before casting. The resin is not very friendly with water. Actually, the water it's the unfriendly. With the help of a hairdryer and a towel, make sure your mold is completely dry. Now, it's setup time. With the help of more LEGO or rubber bands, set up all your molds and materials before continuing.

Label your syringes and things to avoid confusion. Also, if you extract resin with the wrong syring, then you can say good bye to all you bottle of resin!

It's also important to have a watch. You will have only 30 seconds to do the mix, and 90 to pour it in all your molds!

Carefully but at high speed, mix the part A with part B and pour it through the holes of the molds! Be sure no to make more resin than you need. In this case, I needed 1,5ml per mold. So, I should used 3ml for 2 casts and 6ml for the four molds. But I've added 2 ml just in case (0,25ml more per mold). After casting I've learned that if you measure 1,5 ml, then you should use 1,51ml.

Then, you have plenty of time to drink a cold soda, or watch something stupid in youtube, or to write something in a blog.

It's important to write what time it is when finishing the pouring. Then, you must wait 15-20 minutes before opening the molds. Before opening them, clean off the resin from your vessel. This will tell you if your casts are finished or if they are nearly finishing the curing process.