Making the Fibre Glass Outer Part of the Mould

Hi guys! Here is the next step of making our silicone inner and fiberglass moulds..

So, once we had prepared the silicone inner for the mould we were then ready to start the process of creating the fibre glass outer section of the mould.

The reason we are applying a fiberglass section is to support the silicone as it would not hold its shape throughout the casting process as it is a flexible material. Therefore the fibreglass acts as a lightweigh support for the the silicone. It would be possible to use plaster and plaster bandages however fibre glass I more durable and a lot lighter.

So lets begin,

DSCF0173 So to begin with we removed the mod-roc and clay wall from around the edge of the cast. Then we used paper towel to remove any moisture that may be resting on the top of the silicone – If the silicone is damp or wet, the fibreglass would not cure. We also trimmed away any excess silicone around the edges leaving a clean edge.

Depending on the surface you apply fibreglass on top of a releasing agent may be needed as fibreglass adheres to pretty much anything however silicone is felxible and can easily peel away.

Once preped, we were then able to move onto mixing the first gel coat of the fibreglass. To do this we began by measureing out half a cup of the gel coat.

 2To ensure we didn’t dip the gel coat over the floor we placed down some plastic sheets to make it easier to clean if we did spill. We also used a wooden flat stick to help scrape the excess off the side of the cup before bringing it over to the table.

It is always to keep in mind cross contamination as you do not want to ruin the full tub of gel coat so we made sure that the cup and stick we used were clean.

 DSCF0179We then added a catalyst which would allow the gel coat to vulcanise. We used the measurer on the bottle to measure up to the ‘2’ mark. Any more that that would result in the gel coat curing quicker than we need which may cause a problem!

 DSCF0180We then thoroughly mixed it together and applied a thick coating over the top of the silicone with a cheap brush.

Health and safety: Never place the cups and brushes directly into the bin after use – Fiber glass heats up when it cures, meaning it is a fire hazard. It is best to let it cure in sight completely.

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Usually you would add a layer of fibre glass strands to the gel coat (however we forgot to do this part!)

Once the gel coat was applied we then left it to cure for around an hour. This would allow the gel coat to cure but not become completely dry – leaving the surface slightly tacky ready for the next step.

 DSCF0191We then cut 3inch square pieces of fibreglass matting in preparation as our hands were about to get sticky! We cut around 13-15 pieces just to make sure we had enough. We then laid out another piece of plastic sheeting onto the table to protect the surface. we then laid out 4 pieces of the matting onto the plastic to preparation for the next step.

 DSCF0184Next we measured out half a cup of laminating fibreglass resin (using a new cup – to prevent cross contamination) we also added the catalyst to the resin using the same measurement as before (up to the measurement of ’2’ on the neck of the bottle). We then mixed it thoroughly.

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We then used a brush to paste a layer over the tacky surface of the gel coat this will help the next layer adhere. We then used a brush to saturated the 4 piece of matting we had laid out with the resin. Once all four have been coated the first square we painted would have had time to absorb the resin making it softer – allowing it to mould to the shape of the silicone inner.

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We then applied each square onto the surface of the painted on layer of the resin. We then used a paper mache method by pasting another coat over the top of the matting to make sure it was flat without any air bubbles. We made sure each square overlapped slightly to make sure there was not gaps.

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We then left it to dry for around 20 minutes until it goes a green colour. To prevent using power tools we cut the edges of the fibre glass at this time as the fibre glass is solid but still flexible. We then repeated the process – adding a second layer. Then we left it to dry completely over night.

That is all for now! I shall be posting the next stages after next weeks lesson!

Thanks for visiting my blog!

Katy xx

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Preparation Ear Casts for Silicone and Fiberglass Mould

Hiiii again! Another special effects studio update! This lesson we were preparing for fiberglass and silicone moulds, this involved us ‘bedding in’ a ear cast into water based clay. The reason this is a vital preparation stage it to eliminate any possible undercuts in which may lock the mould. So lets get started!

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This is a vital preparation stage.  As I will be using a fibreglass moulding method I need to make sure there is not risk of the mould locking. To ensure this I need to make sure I fill in any undercuts that may prevent the fibreglass from releasing from the cast. To do this I will be placing the ear cast in a bed of clay building up each side. First we made sure to place the positive cast on a wooden board to make it easier to manoeuvre around and build the clay wall. We then secured the ear cast onto the board with clay before building up the sides.

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Tip! At first I struggled to get my head around the idea of undercuts however, Becky (our SFX teacher) told me a really good method of figuring out where any undercuts may be hiding. The trick was to look at the cast from a birds eye view – anything that I couldn’t see from this angle (for example the underside of the ear lobe) needed to be filled in with clay.

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Once I was happy with the bedding in process I was then able to build up a clay and Mod-Roc wall in preparation for silicone.  We then applied a light layer of Vaseline to the ear cast as silicone can adhere to plaster.

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Once prepped, we were then able to begin mixing the silicone.  First we made sure we had all the necessary materials and tools to do this.  We first began by zeroing the scales whilst the plastic bowl was on top to make sure we get an accurate reading as it is vital that the silicone is measured out precisely as it will not vulcanize.  The equation for silicone as are follows:

Part A of silicone:
100%

Part B Silicone:
10%

Accelerator:
1%

For the size of the positive face cast I was covering I wanted to mix up 70 grams of part -A 7 grams part -B and 0.7 grams of accelerator to speed up the vulcanisation process.

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Before mixing we made sure that the tubs of silicone were very close to the scales as it can drip really easily which can be difficult to clean up when not mixed as it stays in its liquid form. To avoid and drips whilst measuring out the silicone we also used a wooden stick to scrape the excess silicone from the sides of the cups. We first measured out parts A and B and then added the accelerator and mixed them together really well to ensure all the silicone would cure.

Tip! An important thing to remember when mixing up a batch of silicone is to avoid cross contamination of each part as this could ruin the full tub of silicone and its isn’t cheap! To avoid this make sure to use different cups and wooden sticks when measuring out each part.

We then poured the silicone into the centre of the positive to allow it to drip over the entire surface. This is only the first layer so it does not need to fill to the top of the clay wall.

Tip! To avoid air bubbles during this process it is always best to pour the silicone from a height as this eliminates the hair bubbles as it pours.

We then set the positive aside on a flat surface to allow the silicone to level out and cure. Due to the accelerator we would be able to come back and add the next layer in around 2 hours.

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The next later of silicone was of a different consistency to the first as we used a different product – Thixo Additive. We carried out the same process as the first layer however we mixed the Thixo at the very end. There was no precise measurement for this ingredient as it was simply to thicken the silicone up to a state I was happy with. The consistency I was looking for thick paste which I would be able to apply generously over the first layer of silicone. If the first layer is still a little tacky that doesn’t matter as it will help the next layer adhere better.  Once the past was mixed we then used another wooden tool to spread the mixture around (Some may fine using a brush easier – but keep in keep in mind it will damage the brush – so think cheap and cheerful!). We then left it to cure for a further 2-3 hours.

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Once the second later had cured, we then added another liquid layer over the top (same process as the first layer) this smoothes over any lumps and bumps from the second coat

Then you are ready for the fibreglass outer casing!

I will be posting the next step very soon, so stay tuned ,

Thanks for visiting my blog,
Katy x

Preparing Silicon Inner For Fiberglass Moulds

HI! Just another up date about what we have been getting up to in the special effects studio. Last week we were making a start on a different type of mould –  Fiberglass outer and silicone inner.

First we had to make the silicone part of the mould. To do this we used life casts of fellow class mates we had made last semester. If you would like to have a quick look of how we did that just click the following link: https://kathrenelizabethmakeup.wordpress.com/2013/09/29/face-casting/

So here goes!

You will need:
– Clay
– Mod-Roc
– Vaseline
– x2 cardboard cups
– Silicone part A and B / Accelerator (optional)
– Measuring scales
– Wooden sticks (lolly pop sticks)
– Gloves Optional)
-Plastic bowl

DSCF0120

First began by applying a light layer Vaseline to the already shellaced face cast. This ensured the silicone we were about to apply would not adhere to the surface of the plaster. Next we placed the positive onto a wooden board to be able to build up a clay and Mod-Roc wall around the positive. This ensures the silicone would not spill out over the table. To make it easier to make a neat clay wall we used a clay block to flatten out the clay so we were then able to cut it evenly to fit around the plaster. As an extra precaution I blended the clay onto the wooden board. We then added a few layers of Mod-Roc around the clay.

DSCF0121

Once prepped, we were then able to begin mixing the silicone.  First we made sure we had all the necessary materials and tools to do this.

KathrenElizabethMake-upFaceCasting (41)

We first began by zeroing the scales whilst the plastic bowl was on top to make sure we get an accurate reading as it is vital that the silicone is measured out precisely as it will not vulcanize.  The equation for silicone as are follows:

Part A of silicone:
100%

Part B Silicone:
10%

Accelerator:
1%

For the size of the positive face cast I was covering I wanted to mix up 100 grams of part -A 10grams part -B and 1gram of accelerator to speed up the vulcanisation process.

KathrenElizabethMake-upFaceCasting (35) Before mixing we made sure that the tubs of silicone were very close to the scales as it can drip really easily which can be difficult to clean up when not mixed as it stays in its liquid form. To avoid and drips whilst measuring out the silicone we also used a wooden stick to scrape the excess silicone from the sides of the cups. We first measured out parts A and B and then added the accelerant and mixed them together really well to ensure all the silicone would cure.

Tip! An important thing to remember when mixing up a batch of silicone is to avoid cross contamination of each part as this could ruin the full tub of silicone and its isn’t cheap! To avoid this make sure to use different cups and wooden sticks when measuring out each part.

DSCF0112-horz

We then poured the silicone into the centre of the positive to allow it to drip over the entire surface. This is only the first layer so it does not need to fill to the top of the clay wall.

Tip! To avoid air bubbles during this process it is always best to pour the silicone from a height as this eliminates the hair bubbles as it pours.

 DSCF0123

We then set the positive aside on a flat surface to allow the silicone to level out and cure. Due to the accelerator we would be able to come back and add the next layer in around 2 hours.

 DSCF0133

The next later of silicone was of a different consistency to the first as we used a different product – Thixo Additive. We carried out the same process as the first layer however we mixed the Thixo at the very end. There was no precise measurement for this ingredient as it was simply to thicken the silicone up to a state I was happy with. The consistency I was looking for thick paste which I would be able to apply generously over the first layer of silicone. If the first layer is still a little tacky that does not matter as it will help the next layer adhere better.

DSCF0118Once the past was mixed we then used another wooden tool to spread the mixture around (Some may fine using a brush easier – but keep in keep in mind it will damage the brush – so think cheap and cheerful!).

DSCF0137

We then left it to cure for a further 2-3 hours.

 DSCF0112-horz DSCF0112

Once the second later had cured, we then added another liquid layer over the top (same process as the first layer) this smooths over any lumps and bumps from the second coat.

Then that is it for the silicone inner! I’ll be posting  the next step very soon!

Thanks for reading 

Katy x