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Oryx 2 of 6 - Mould by differentiation Oryx 2 of 6 - Mould by differentiation
After the sculpt has been walled up, it is ready for moulding.

I used TOMPS Value Range silicone to mould this project, with a slow catalyst. (Although I prefer the fast catalyst, as I am impatient, but it is VERY fast)

The silicone is degassed in a vacuum chamber before being poured on.

The first layer of silicone is a detail layer, and is poured on in a thin layer so it flows into all the details.
The second layer, which is applied after the first layer has cured, is a much thicker layer, which builds up the thickness and strength of the silicone.

I thickened my silicone using cab-o-sil (fumed silica) powder, (but in future I would use a thixotropic additive for the silicone, as I found the cab-o-sil slowed the cure of the silicone)

After the thicker layer has been applied, I put keys into the silicone, so that the fibreglass jacket has something to 'grab hold of'. The keys are little rectangles of silicone I cast out earlier.

Once the silicone has cured, it's time to apply the fibreglass jacket. I walled up down the centre of the mould in clay, and brushed shellac over the clay to seal it, as moisture inhibits the cure of polyester resin.

I wet out my fibreglass on a silicone mat, as it's easy to clean, and is reusable.

The fibreglass jacket consists of a gelcoat layer, then two fibreglass matting layers, finished with a layer of fibreglass tissue, which makes the mould much nicer to handle than a sharp, spiky mess of fibreglass matting.

Once I have glassed out one side of the mould, I trim it with a sharp knife before it cures, to neaten up the mould, and then wait for it to fully cure.
The clay wall is removed, and the fibreglass flange is released with lard (my preferred release agent, as it is cheap and easy to use.)

The glassing process is then repeated for the other half of the mould.

Once both sides of the mould have cured, I drill holes for bolts before taking the mould apart, as this ensures the mould is in the correct place once it is put together.

Next stage is casting out the resin skull.
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R-Complex25 Featured By Owner Sep 26, 2015  Student General Artist
Beautiful moldmaking work! Though usually I see most artists brush or stipple on the "gel" layer of the silicone mold in order to prevent air from being trapped in the detail portions. I presume its a very thin silicone, so that no air would be trapped pouring it on.  I do like the idea of split jacket nearing the face, nice move on the seam line.

How did you come about that idea of using a jacket mold, I'm always curious as to how folks make these types of molds and what decisions led to that choice.
Fnaf-Clara-Cockatiel Featured By Owner Jun 4, 2015  Student Artist
I heard you can do the molding with clay too. Is that true?
AlexXe666 Featured By Owner Mar 3, 2014  Hobbyist Artist
hey, wow great work! i'm a fursuiter too and live in hertfordshire.
Just wondering, where did you get your silicone from? i've been looking for some for a while now and can't seem to find any in the uk?
can you help me please? Keep up with the amazing work! :D
KuzunohaxX Featured By Owner Apr 14, 2014  Hobbyist Interface Designer
Ok I know this sounds crazy and ridiculous, but I buy a bunch of pure silicone swim caps and melt them😂 ok so maybe it seems a little strange and stuff but it works pretty well and doesn't cost much at all! You just gotta make sure you keep the pot you use to melt it warm enough so that the silicone doesn't harden and get stuck to your pot, which can be a little tricky but you'll get the hang of it after a while!!!
AlexXe666 Featured By Owner Aug 19, 2014  Hobbyist Artist
Really... or is that sarcasium i'm hearing? 0.o
I thought you brought the silicone from tomps?
Really. Ok then why don't you show me a video or tutorial of you using the silicone swim caps, then?
LMFAO!!!! Thanks for the help and the genurious information that you have given me. :)
ThoronINC Featured By Owner Sep 29, 2011
just like what ive been up to today, but with less dureible plaster bandage.
this method looks as if it will last a long time.
may i ask dose your sillocone or laytex react with the sun?
differentiation Featured By Owner Sep 29, 2011  Professional Artisan Crafter
I've tried out plaster bandage before, but I found it just didn't have enough integral strength to keep its shape very well.
Using plaster reinforced with jute scrim (used the same way you would plaster bandage), tends to give a much stronger result (and it's usually cheaper than buying rolls of plaster bandage), although it does require walling up, similar to this method, and it's important to release the other half of the wall with a layer of clay slip.

The silicone should last for around 50 pulls at least - more if I sprayed release agent into the mould before pouring resin =)
The mother mould will easily outlast the silicone.

As far as reacting with the sun. UV will degrade pretty much anything - unless it has a UV protection agent in it.
Just a note - be careful about using latex as a mould component as it can shrink quite considerably when not reinforced with anything.
KuzunohaxX Featured By Owner Apr 14, 2014  Hobbyist Interface Designer
I would recommend not using latex at all if you plan to sell the mask. A lot of people are allergic to it (like me) and will end up with some very nasty, itching, oozing hives on their heads if you do sell it to them. Trust me, it's easier to work with silicone and it will save you a lot of money since you won't have to make special latex free masks and molds and potentially save you some customers.
ThoronINC Featured By Owner Sep 29, 2011
ohh thank you that helps so much,
The fibere glass mold would also last alot longer.
differentiation Featured By Owner Sep 29, 2011  Professional Artisan Crafter
It's not pleasant to work with though - plaster is a much safer option, especially if you're working at home.
A plaster mould can last just as long as a fibreglass mould - next time I make a plaster mould, I'll be sure to document it in photographs and put together another step-by-step image.
ThoronINC Featured By Owner Oct 1, 2011
yehh good point. But I hear its better for tight moulds and multiple part moulds.

Ive been doing a wolf sculpt via guessing, no tutorals and its turning out verry good, Il post some pic son :iconthoronwild:

Ohh sounds cool.
Have you made any other animal form the oryx?
differentiation Featured By Owner Oct 2, 2011  Professional Artisan Crafter
Had a look at your wolf sculpt:
It's a good start to a sculpt - one way to smooth out oil-based clay is to brush white spirit/lighter fluid over the surface, the same way you would use water to smooth out a wet clay sculpt.

Plaster works just as well as fibreglass for multiple part moulds. I'm not quite sure what you mean by 'tight moulds' though. The major reason fibreglass is usually favoured over plaster, is that it's lighter, and generally won't chip/break if you drop it.

I'm planning to try and make some more herbivore masks from this mould - goats etc. I haven't done anything more with it yet though.
ThoronINC Featured By Owner Oct 3, 2011

Il try that, but wouldnent that ruin the clay?

Youre base would also make good dragons.
differentiation Featured By Owner Oct 4, 2011  Professional Artisan Crafter
It hasn't ruined any of my clay =)
(1 Reply)
Antella689 Featured By Owner Sep 28, 2011
mmm, the perfect solution!
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Submitted on
September 27, 2011
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