Silicon Moulding


Greensil is a 2 part putty (mixed 1:1 per volume) that has a working time of 8min and a demold time of 20min which is of particular use in a workshop scenario where time is an issue.

Process for using and selling greensil

What you need

  • Scales
  • 2x smll poly bag (or 2 plastic cups)
  • 2x paddlepop stick
  • clean space to work
  • form that you want to make impression mould of
  • time piece

Process 1. put a plastic cup (if its going to be used straight away ) or a poly bag (if they aren't using it immediately) )onto the scales and zero the scales 2. Dig out a potion of Part A ( white ) with a paddle pop stick and place it into/on the cup/ polybag

3. weigh out a the required portion min 10 grams of part A

4. Repeat with Part B (green) making sure you don't cross contaminate (use a different cup/polybag and paddle pop stick.

5. Record the amount taken from stock (10g) the date and your initials. Ensure lids are resealed

6. Charge for the amount provided using the online materials form

7. Mash the two parts together until they are mixed - if you can see streaks of white in the mix you need to keep mashing. You have up 6 min working time, so you need to get it mixed and make your impression in this time.

  • Press the form into the mixed putty. When you make your impression be mindful of how you will later use the cast.
  • After 20 min the putty should be cured and you can demould.

Silicon Casting

The Edge currently stocks 2 varieties of pour casting Silicone - Pinkysil and Banana Skin

But Before you can make a silicon casting you need something to contain the silicone. You want the container to be as small as possible so you don't have to pay for as much silicone. So we generally recommend making your own perfectly sized cardboard box.

Here's some basic instructions to make your box

You'll need:

* The item you want to cast.

  • some cardboard,
  • a cutting board,
  • a utility knife ( stanley)
  • a pen or pencil
  • a metal ruler
  • hot glue gun
  • -aybe some tape or rubberbands or clothes pegs

Instructions 1. With you pencil and ruler draw out out the size box base you want by placing the form you copying on you cardboard and draw a square (or other flat-sided polygon) around it. Remember the less space around your form the less silicone you need to use and the less CA$H M8-) NIE$ you need to pay. Of course don't go to overboard cause you don't want the form touching the side of your box.

2. Now draw the sides of you box radiating out from the straight sides of the base. Ensure you make these sides deep enough to contain enough silicone to cover your form. handy hint the box needs to be a little deeper that the object you are casting ;-)

You can see that i have added some flaps to each of the vertical sides of the box, this will give you something fold over and glue the sides together.

3. Now carefull score (slightly cut) the fold lines of your box (straight lines round the base and fold lines for flaps)

you can use a rubber band, tape or a pegs to hold your box in shape

4. Now put a dab of hot glue on the inside of each of you tabs

And if you like bed of hot down the joins to seal these.

5. When you pour your silicone cast you don't want the original form floating around in the curing silicone. So most people blutac down, or find another method securing the form to the bottom of you containing box. Be careful though that you have you original form oriented correctly.

You are now ready to start preparing your silicone

Process for using and selling Pinkysil or Banana Skin

What you need

  • 2x 30ml Syringes
  • 1x plastic cup (for mixing)
  • 1x paddlepop stick (for mixing)
  • clean space to work
  • form that you want to make impression mould of
  • Container ( the box you just made)
  • time piece
  • Parts A and B of Pinkysil or Banana Skin


1. Lay out all of your equipment and consumables on a clean workspace.

2. Shake Part A and Part B bottles vigorously for 30 sec.

3. guestimate (in mL) what volume casting silicone you will require. Half this and then add a bit for good luck.

4. using a 30mL syringe, measure out the required portion that is required of Part A (Pink / Yellow) and place this in you plastic mixing cup.

Ensure the lid is resealed correctly.

5. With another 30mL syringe, Repeat step 3 with Part B (clear).

Do not cross-contaminate the two parts by reusing the same syringe. Ensure the lid is resealed correctly.

6. Place Part B in the Mixing cup with part A and stir with a paddlepop stick.

7. Pour well mixed silicone solution over the form that you have secured at the bottom of the container.

8. Record the amount taken from stock (10g), the date and your initials.

9. Charge for the amount provided using the online materials form

After 20 min the silicone should be cured and you can demould.

Casting Materials

  • facilities/fablab/materials/casting_materials.txt
  • Last modified: 2018/07/23 14:27
  • by Michael Byrne