Rubber

Rubber http://elasticrubber.wordpress.com Wed, 05 Nov 2008 18:38:58 +0000 en hourly 1 http://wordpress.com/ http://s2.wp.com/i/buttonw-com.png Rubber http://elasticrubber.wordpress.com How to Make a Rubber Mold http://elasticrubber.wordpress.com/2008/11/05/how-to-make-a-rubber-mold/ http://elasticrubber.wordpress.com/2008/11/05/how-to-make-a-rubber-mold/#comments Wed, 05 Nov 2008 18:38:58 +0000 selvakumar123 http://elasticrubber.wordpress.com/?p=3 ]]>

Find something that you wish to mold. Could be a pine cone that you wish to make into candles, an animal that you’ve sculpted and want to duplicate to give as a gift, anything that you want.

Look for mold making material. There are a number of companies that sell rubber for making molds. Type “mold making materials” into Google for a list of suppliers.

Build your mold box. You will need to surround your model with some sort of wall to contain the liquid mold rubber. Generally you should leave 1/2″ between the walls and your model, use a yogurt container, or make a custom form out of foam core and hot melt glue.

Determine if you need to seal model. In order to make sure your model will release from the mold rubber you must first seal your model if it is porous, and you may also need to apply a release agent. If your model is made of wood, plaster, unglazed ceramic, stone, concrete etc. it is porous and needs to be sealed with Krylon clear acrylic spray or with a sealer available from the mold rubber supplier.

Apply proper release agent. If you are using a urethane mold rubber and your model is anything other than silicone, you will need to apply a silicone based release agent. If you are using a silicone mold rubber and your model is anything other than silicone, you do not need a release agent. If you are using silicone mold rubber and your model is made of silicone you need to use a non-silicone based release agent.

Mix and pour your mold rubber. There should be instructions with the material. Be sure to mix both sides first before measuring out how much you need, (Some suppliers have tools to estimate how much you will need.) Thoroughly mix both sides together and pour at the bottom next to your model. Don’t pour directly onto your model or you may trap air and lose surface detail in the mold.

Demold. After waiting the proper time, usually overnight, poke the rubber to make sure it is fully cured and not sticky. Remove the walls of your mold box first, using a razor blade if necessary. Hopefully you will now be able to push with your thumbs down in the center to break the air seal and remove your model from the mold rubber. Depending on your model you may have to use a sharp knife to create a seam and cut the rubber to release it.

Inspect. You are done! Congratulations you have just made your first mold. Visually inspect the inside to verify that it captured all the detail you wanted. If you find imperfections make a note so that you can correct it in the future. You are now ready to cast anything you like! Try Plastic, plaster, Ice (Water swells when it freezes), chocolate (some mold rubber is food safe, most are not) jell-o, wax, Foam, etc.

Start the rubber band ball by simply wrapping a single rubber band around a small marble or a quarter(two pence coin) until the band is tightly stuck around the marble. Or,maybe to start, you could use a small pencil to start the ball by wrapping the rubber band around it. Then, try sliding the rubber band off the end of the pencil. It will be a small, tight ball made out of a single rubber band. Instead of the pencil, take a small piece of paper or aluminum foil, and crumple it up many times so that it is a firm and very small sphere. Start wrapping the rubber bands around that. It will give you a solid center to start with.

Or you can take three or four rubber bands and roll them in your hands until they are compressed slightly. Hold it with one hand and….

Wrap another rubber band around that one.

Keep wrapping rubber bands around and around till there is no give on it, and it’s tightly wrapped.

Before you put each new rubber band on the ball, toss it up in the air with a little spin (it doesn’t matter what direction). This ensures that the ball will have a new, random orientation when you put each new band on. It will also keep your hand from cramping up, and keep the ball balanced.

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