Silicone Rubber Mold Making Tutorial

After a busy week I can finaly tell that I finished the mold I started. And as promised I will give you a small tutorial so you can understand the process. If you get this by e-mail it might be easier to click the blue title link which brings you to my blog site and it might be easier to read that way.

We start ofcourse with the object that we want to use, which in this case is a head bust.

 When you take a good look at the objects you can then decide where the line of the mold is going to be. Since the silicone rubber is quite flexible you don't have to worry about small undercuts too much. So after you decide where the line is going to be you fill up one side with clay so that the rubber cannot get attached to it. The clay is also used to attach a little piece on the bottom that will later become the pour cup of the mold.

After you filled up the other half of the object with clay we press some holes to form so called "keys" these will help the 2 parts of the mold stick togheter better when it is done.

Then you make a wall around so that the rubber stays where it should be and doesn't float on the table (Sounds logical right?).

Then comes a small but very important part (people who have forgotten this once will know what I mean). You use vasaline to cover the object so that the mold doesn't actually gets stuck onto your piece).

After that you can mix your rubber mold and start to pour the first layer over your object

When it spreads out it will look very thin on the higher places so you might need to apply a second layer.

This second layer is also good if you didn't have enoug rubber to cover all the keys and empty space.
After you have done this you can let it set for a couple of hours untill it dries out).

The next step involves adding thickner to the rubber mold mix so you can apply it better and thicken the mold out on thinner places.

Again time for drying.

Now we have made the first part of the mold, so we remove the walls and add more clay. This will be for the second part of the mold which will be made out of plaster. The plaster will function as a support for the rubber so it keeps its original shape.

This part basicly goes the same expect for the fact that it is done with plaster, and doesn't need vasaline.

Then pour the plaster and make sure you add some extra on the higher points of the object.

When the plaster is almost set you can remove the walls en soften the edges out while it is still easy.

After leaving it for a while (overnight might not be a bad idea but isn't necesary), you can turn over the mold and remove all the clay used.

Clean up the mold and again use vasaline to prevent the rubber mold from sticking to the other part of the mold.

When you build up the walls make sure you don't forget to put back a piece of clay for the pouring cup.

This part is pretty much the exact same as it was on the first half of the mold, pour the first layer.

Wait for it to float out and apply more if needed.

Again let it dry out.

Then use the hardner in the mix to add thickness to the mold again

When finished you can remove the walls again and clean up the plaster from the first part of the mold.

Rebuild walls for the last plaster pour and remember the vasaline (this is the part where you really do not want to forget adding it).

Pour the plaster in and add some extra to the high points when it has thickened out a bit.

Remove the walls when it is almost completely set.

And use whatever you have at hand to smoothen the sharp edges out.

W then have our final mold which we let dry for a longer time (just to be sure it doesn't break when we take it apart for the first time.

After leaving it overnight take it apart with care and get your original piece out. You now only have to clean it before you can try pouring wax in it and see if it came out well.

Unfortunately I didn't have time for that last part this week so that will hopefully follow soon. I hope you enjoyed my short tutorial, thanks for reading.