Kate Garrett
Make-up Exploration
Processing Silicone Prosthetics.
Health & Safety.
* Wear Protective equipment/clothing.
Hand protection - The chemicals used contains organic peroxide so you will need to wear vinyl or nitrile gloves (NOT latex). It is surgested to wear two layer if one pair gets ripped you are then protected still, the damaged one can easily be removed and replaced without risking irritating your skin.
Eye Protetcion - Wearing glasses to minimise the risk of it entering and irritating your eye.
Clothing protection - Wear disposable overall's or baggy clothes as if the products spill on you during the process you can quicky remove/pull it away from the skin to stop it from burning/irritating, minimilising the risk of injury.
* Use in a ventilated room
The resin in liquid form is very toxic so is very dangerous and must only be used in a well ventilated room.
* Do NOT breathe in the material.
You must always wear a respirator to stop the glass fibres for entering and affecting your respatory system tempoarily or permantly.
Respirators.
There are two types:
Disposable - This is perfect if you are only needing to use one as a one off but not suitable for long term use as these will last around 3 months once the packet has been opened, cheap to buy at first but the upkeep cost is more expensive.
Reuseable - These you buy the mask and then the filter that fit onto the sides. Have a long life span as long as they are looked after and the fliters are changed every 3-6 months.
When is this process used?
This is a process that is used across many industrys to create a wide variety of objects such as aeroplanes, boats, molds, etc.
What does GRP stand for?
Glass Renforced Polyester.
Why is fibre glass used?
* It is strong but lightweight
* It is less brittle than carbon fibre but not as strong
* The making process is easy
* It cures quicker than other materials, saving time and money
* The raw materials for this process are cheaper than others
The downside..
* It is inflexable so has none of the movement a rubber mold has.
* It is very hard to work around undercuts and most fibreglass molds made that cover a undercut cannot be removed with breaking the mold
* The layering process can take time
Fibreglass (GRP).
Image 2.0 - Reusable Respirators, 3M Easi-Sir paint spray respirator Assembly
Filters.
There are different levels of filters that fit into the mask to proetct your correctly for the materials you will be using this table is available from the manufactuer to enable you to choose the correct one for your job. Below we see these colour bands for this unit I will be using the black band filters.
Image 2.1 - Coding for filters
Changing your filters.
You must see the use by date on the packet of the filers to know how many months you may use them before changing them however if you see any damage to the filters, your breathing becomes more difficult that it has previously when uses your mask then you need to change them at this point rather than wait any longer to minimise risk of damage to your respatory system.
Materials.
The materials that are used for the fibreglass process are; Glass matting, gel coat resin, lay-up resin, fine surface tissue (vale) and a catalyst (benzoyl peroxide. Below I explain each material, relevent health and safety and what it is used for.
Glass Matting.
There are different varieties this comes in, they are;
* loose chopped strand (choppies)
* fine surface tissue (also refered to as vale)
* Woven matting
* fg tape/rope ???
Gel Coat.
This is the first layer that is created over your sculpt.
* Collects all the fine detail
* Type of resin
* Prethickened and smooth
* Hard polyester
Lay up Resin.
* It's an adhesive that strangthens the mold.
* Changes colour once catalyst has been added
* Soak the matting in it to give it strengh
Catalyst.
Two cataylsts are:
* Methyl Ethyl Ketone Peroxide (MEKP)
* Organic Peroxide (Butanox)
Follow manufactures instructions on the percentage of catalyst to use.
Health and Safety - If this comes into contact with your skin it will burn!
Making the Mold Method.
1. Prepare yourself as described in the health and safety section.
2. Cover the plastic core with the mould release wax.
3. Cover the sculpt in talc. This will allow you to see where you have placed the product and where you haven't.
4. Mix the gel coat and catalyst together so the mixture chanages colour, this indictaes that it is mixed throughly.
When adding you catalyst to the resin follow the instructions on the label. In this case you will 2% of the catyalst to the resin.
5. Apply all over the sculpt and plastic core with an even thickness, before leaving it to cure you need to make sure all air bubbles are removed. Then leave for around 25-30 minutes for the gel coat to cure - firm but tacky.
Be aware the air temprature may speed up/slow down the curing time.
6. Prepare all your matting for the next stage, it is advised to rip it up into smaller squares as this helps to make a stronger mold.
7. Mix up the lay up resin and cataylst, once agin when it has changed colour it has been throughly mixed and ready to use.
8. Then add in choppings, it should be a smooth paste constiancy (mud). Then apply this mix into deep areas that may cause issues if they weren't filled in.
9. Wet the matting and allow it to soak it up slightly then apply ontop of the gel coat using you laminating brush to push it into the creases of the sculpt. Repeat this so you have a full coverage over your sculpt.
10. Brush resin over the top to conform and confirm that the matting is following the shape of your sculpt. (knocking out).In total you will need 3 layer of the matting.
11. Then apply 1 layer of suface matting (also known as vale) over the top and allow to cure over night.
Gel coat layer Preparing matting Layering matting on sculpt.
3 Layers of matting and lay up resin.
Suface tissue (vale) layer.
Demoulding.
1. Draw round the edge of your grounding and mark in spots where your drill holes need to be.
2. Drill a series of 6mm holes through the fibreglass mold and the core. Drill the most central point you can at either the top or bottom then the next two holes at the side of the cast, These will act as your starting points. You should follow the pattern of DRILL, BOLT, DRILL BOLT....
3. Once these three holes have been bolted go round and drill the other marked holes, having the three pointed bolted down will keep the piece it the same places stoppping your piece from moving.
4. Remove the fibre glass mould off the core the using the fin multitasker cut along the marked edge then sand down to a smooth finish.
5. Clear out all the clay from the mould, you may need to work in some mould release with a stumpy brush and wipe out the tiny amounts of clay. Then you are ready to create your prosthetic pieces.
Methods of creating pieces.
Method 1.
Pouring silcione/gelatine in.
Silcione.
This is the same method as used for flast pieces. 3-4 layers of cap plastic and IPA on the core and mould. Pour the silicone in then bolt the mould and core together, leave to cure then remove.
Gelatine.
Melt in the microwave then pour straight into the mould, bolt together and allow to set.
Method 2.
Injecting silicone/geltaine in.
Silcione.
Drill a hole matching the size of your seringes into th edeepest part of your prosthetic piece (on the core side). Then prep the mould as for the other method. Then prebolt the core and mold togther. Inject the smount of silicone needed in throught the hole in the core, leave the seringe in and allow to cure.
Gelatine.
This is the same as above but not prepping the core and mould with cap plastic and IPA mix.