How To Make Your Own Custom Silicone Soap Molds Tutorial

By Kaseen Cook, Tortuga Soaps

Silicone soap moulds are great for custom shapes and
applications,and easy to make in an afternoon. You can create very precise
looking soap shapes from all sorts of shapes and sizes of containers,
or carve your own soap shape.

Materials:

• RTV silicone (preferably one with a Shore A hardness of 20 or
  greater for the stability of the mould (so your soaps dont come out
  twisted if your mould is not flat) and to reduce the thickness of
  silicone needed on the edges and therefore the overall cost per
  mould. In this instruction pamphlet, we are using Pinky silicone by
  Barnes in Australia. It is available locally at most fiberglass shops or
  online at Barnes or Adelaide Molding and Casting. Pinky is ideal
  because it has an easy 1:1 mix ratio, is skin safe with no fumes, is
  very fluid which reduces bubbles in the mould, and sets in about 20
  minutes (as opposed to most which take 12-24 hours). It is a bit more
  expensive than other silicones, but is worth is for its great
  properties.
• Wood, plastic or cardboard strips about 5-9cm tall for
  framing the
  moulds. (Anything that makes a good corale)
• Plaster of Paris

METHODS:

• Mix plaster to a pudding like
  consistency, and pour into the
  container that you would like your soap to be shaped like. Or
  pour into a block to carve your own. Let set for 30-40 minutes
  or till cool (plaster will warm up as it chemically hardens).



• Unmold your plaster soap, tidy up and
  polish. When
  removing and smoothing jagged edges or when sculpting the
  bar, working under a light stream of water really helps to
  make the cuts very smooth and wash away debris. You can
  also polish or patch your bar by taking some freshly mixed
  plaster and lightly smoothing a tiny amount over the bar with
  a finger while under light stream of water. This deposits a thin
  layer of fresh plaster that is smoothed and shined by the
  trickle of water. At this stage, it is advisable to make a silicone
  mould of the plain soap model iincase the engraving doesnt go well on the first go,
  or if you accidently drop it or may
  want to engrave something different in the future it
  definitely saves time and anguish to have a mould of the
  original!



• Prepare your design for transfer to
  the plaster and print with
  an ink jet printer (or any printer with water based ink, youll
  know it is water based if it bleeds when it gets wet). I make
  my designs in blue (as blue ink transfers better than black),
  and then flip horizontally so the text will read correctly when
  the paper is face down. If you are having a hard time flipping
  or colouring your design, just shoot me an e-mail and your
  design to kaseencook@tortugasoaps.com.au, and I can easily
  help format your design for you and save you the frustration
  if you are not computer savvy.



• On your moist plaster model, with a
  dry surface, press the
  design with a wetted finger (but not too wet! Just moist), just
  until the deign shows through the back of the paper and is not
  bleeding horizontally. If is it bleeding horizontally there is too
  much water and/or your plaster surface it too wet (sit on a
  dry towel for 5min to soak a bit out) and/or you are not using
  enough pressure to squeeze the ink directly downwards and
  into the plaster.





• Engrave the design by removing the
  plaster where the ink is.
  The ink will fade gradually, so it is best to engrave right away.
  If the design is complicated and will take a while to engrave,
  go over the whole design lightly with a tool to just scrape the
  surface, then when the ink fades the design will still be there
  and you can take your time engraving. To make a deep
  engraving, it is better to do a little at a time from each letter or
  area and go back for multiple passes. This helps to avoid
  breaking plaster in tiny details and makes for a more accurate
  carving. You can use small flat screwdrivers, long needles,
  thin tweezers, tools from a dissection kit, or whatever you
  want! It is best to keep the plaster moist while working,
  because dry plaster is hard to carve, dusty and messy, and
  chips and breaks really easily when engraving.



• Rinse the debris from your model and
  sit bottom down on a
  dry towel to absorb surface water. Be careful not to towel dry
  the top and sides that will be in the mould, because lint from
  towels can get onto the model. When sitting on a dry towel the
  water is absorbed downward into the towel and pulled from
  the top surface first, so there is no need to directly dry it.
• Set up your mould frames on a sheet of
  paper on a flat surface,
  leaving about 5-10mm around the model (more - for softer
  silicone and/or larger soap models, less - for smaller soap
  models and harder silicone). Tape around all cracks and
  corners and edges to ensure no leaks. You can also use putty,
  clay or hot glue, but tape is by far the easiest and least
  damaging method to use. I used scrap wood, but you can use
  any thing that makes walls (like cardboard or plastic).



• Mix and pour your silicone. Pour the
  silicone in a thin stream
  into the lowest point (around the sides), so the model is slowly
  covered. Check out Tap Plastics site for videos and use of the
  “bombs away” method of pouring. Air bubbles can get
  trapped in the silicone and up against the model. To avoid this
  for detailed designs, you can rub silicone into the details of the
  model first to ensure there are no bubbles, then place into the
  frame and pour the rest of the silicone. Most small guest soaps
  take about 60ml of silicone; larger ones can take 100+ml of
  silicone. You can pour rice into the space to measure the
  volume you need. Just leave everything that you get silicone
  on (cups, stirs, ect...) until the silicone is hard and peal off for
  an easy clean. Beware of working over carpet or fabric,
  silicone can soak into fabrics and carpet and be hard to get out.



• Allow to harden and then unmold and
  trim the scraps!



• Viola! Hope you had a good time and
  will be able to make
  tons of unique moulds and soaps!
• If you want to make many moulds at
  once, you can make
  more plaster copies of your soap bar by pouring plaster into
  your first soap mould, quickly making you lots of plaster
  copies which you can arrange in to a slab or grid for many
  moulds.

Common Issues with Making Soap in Silicone Moulds:

Sometimes pouring CP soap into the molds can cause soap
bubbles
to get trapped in the details and corners. To help the soap flow into
every detail, you can rub the inside of the mould with your soaping
oil or water.

Silicone is not great a great insulating material. For
some climates
and soap recipes, this means that the soap will have a hard time
gelling and may come out soft or take a long time to cure. Some
solutions include keeping the moulds insulated in a wooden box or
with towels, CPOP by putting your full moulds into a warm oven to
force gel, and reduce the water content of your soap to around 25%
water as a % of oils to increase the speed of saponification and to
make a harder and denser soap.

(Please do not reproduce, distribute or sell without
permission information is give in good will
and we are not responsible for damages or losses resulting from the use of
our instructions and
tips)

Author: Kaseen Cook, Owner of Tortuga Soaps, Please check out
her website and show her your support!