Tetris Ice Cubes

Step 5: Pouring the silicone

Mix the silicone according to the directions provided. Pay careful attention to whether it asks to measure by weight or volume.

Pour the silicone mix over the wooden blocks, filling the housing to the rim.

Let set according to the directions provided (usually it will be at least 10 hours).

Comments

[vt13013]

Did you tap or vibrate the mold to make sure you didn't have any air bubbles? I noticed a few on the pour images.

[Tetranitrate]

I tapped it a few times to get rid of as many bubbles as I could.

[neckrochylde9]

Mixing the silicone very slowly will also help with air bubbles, check the cure time of your rubber first though, most have more than enough time to be patient when mixing. Ideally you would make a vacuum chamber and vacuum the rubber before pouring it. but be sure not to fill your container more than 2 thirds or less or you'll end up with silicone all over your vac chamber! gooey mess!

[Void Schism]

it also helps to use an old brush to paint a layer of silicone over the surfaces, especially where there are overhangs, before pouring the rest

[Nox Caulis]

http://www.smooth-on.com/Silicone-Rubber-an/c2_1113_1136/index.html

Here's the stuff he used for the mold.

[naruto the ninja13]

make sure you use food grade silicone

[Omegablood]

Where do you get the silicone to make the negative mold?

[shooby]

might be able to just cut an ice cube or two into the right shapes, might be kind of small unit blocks though

[jester_rob]

You might be able to get it at a name brand craft store like Michael's or someplace. I've seen this stuff at the toy train shop by my house so just look around for craft, miniature, or model shops. You might be able to use something like a silicone caulking that you can find at home depot.

[cwebsterlusk]

caulking is a bit too thick for this. you cant "pour" it right and it creates air bubbles. least thats my experience.

[neckrochylde9]

Caulking is also NOT food grade silicone and you should never use it for anything your going to ingest . On smooth on's site, they have a product called smooth sil 940 that they say is food safe. I work in film with smooth on products often. Just because it is silicone doesn't make it food grade silicone, Smooth on has a great help line and they will gladly walk you through what to buy for a project like this!

[Omegablood]

Do you have a name brand for the stuff or the section to find it in? There are several michaels around here.

[apburner]

tap plastic
Try this. I use it for molds for plaster

[Omegablood]

thanks!