Hope this "description" of what I've done helps someone.
What I've learnt:
*if you can use more parts to a mould- do it - simplicity of each mould peice is paramount make keyed multi piece moulds or a hybrid approach (a solid mould where no undercuts- and glove moulds+mother mould for other parts that have undercuts)
*take time- and be prepared to take a lot more time again.
*rooting things up gives you invaluable lessons - let someone else (like me) do it
or try and reduce the cost of errors.
*do things you're never done before- but do them simply
*don't expect things to turn out as planned if you don't take heed of the "do them simply" part.
Onto the diary...
Okay I redid the head - as I wasn't happy with the first one the head looks like :
Went throught the same process of making a 1 peice mould (I'd advise against doing a glove mould for things this "big").
I used 4 layers of "rotathane", quick set (3 minute pot time) solid set polyurethane that you can slush cast, for the body front and back- there was an undercut in the back which made pulling the mould difficult.
The head was slush cast in parts starting at the nose and moving out from there to the back - in hind sight doing the in two parts (solid back mould) and flexible part for the nose/horns) would have been a better idea.
So after re-doing the head we've gotten to the part of demoulding.... the result looks like below.
You can see the moulds are covered with silicone as a release agent - as I will be using the same mould for the foam innards.
The result of how it "fits" together is...Older posts
I've reorganised this to be in reverse chronological order and put thumbnails for following of process. Hopefully it can help people out... if there are any questions ask away... I can give more details into what was problematic so that someone doing a similar thing could avoid the issues I've had along the way. Most materials used are quoted by names of products at Barnes(www.barnes.com.au), so if overseas there will be similar names but different. Over in USA there is Brick In the Yard([link]
), who have great tutorials for using stuff on their you-tube channel ([link]
). So.. hopefully this journal shows useful steps in making stuff.
The body casting has been done in Ultracal 30, this was moderately successful, in pulling the mould the bottom part cracked, but it isn't unsalvagable. So now we have a casting ready for a release agent to be put in there (using "banana skin" again).
I simplified the mould by removing the feet, they will be done in another process. So that I could keep it down to front/back (feet would give undercuts and that would have made the mold difficult.
If you ever want a great tutorial on mixing plaster: [link]
Now I have successfully created a head... So in the end I used a thin silicon to coat the original ("Banana skin"), then a thick on to give it more strength (Gelsil) but still retain flexibility, and made a 2 part mother mould (Trowel-on 60) to keep the flexible components relatively static when pouring the final material. So pulling the mold has been successful- used Rotothane (a pourable mould material) for the final... It isn't perfect, so I may produce another set of molds later... for now onto the body
Part of the body mould is cast - at present it is in UltraCal 30- it will most likely be a 3 part mold due to undercuts. I'll start taking piccies of it as continue to make it.
Part 4: making moulds for head
Okies... the use of a thin silicone was a fail. But what I've done is use the thin layer of silicone to make the sculpt smooth, so I've used a more viscous silicon(gelsil) over the top- hopefully that all works out. Once the head is cast I will make my two (or even three part) mold for the body. If it all goes well will do a few more things (modular dog toy stuff is what I'm thinking.. but that is a discussion for another time)
Part 3: Coarse sculpting
Materials- Klean Klay or oil based reusable clay, hands/palms, sculpting tools
Klean Klay is an oil based clay that works nicely to make a negative mold over, it is great for designing prosthetics and doesn't dry out like water based clay. So your design time can be long and it can be reworked... and reused. Over the aluminium foil you push the clay against the armature - which it generally sticks quite well to it. I coarsely build it up with gross shapes, and the improve the shaping.
Palms work great to smooth the clay, it seems to work better than wooden tools... and the warmer it is the more compliant it is a material.
Anyway... that is where I am... so... will keep adding to this as I go along.
Part 2: Coarse forming
Materials- Aluminium foil, duct tape
Aluminium foil is your friend for making armatures and bulking out areas. Scrunching it up and making coarse shapes is easier and lighter than using clay. The aluminium was taped in place to give the rough shape. And shiteloads of it
Part 1: Pose/shape
Materials- Duct tape (hardware store), cardboard (leftovers from packaging)
Made a cavity for the lappy, out of cardboard... carve up some tubes to stop the box from callapsing, and for the feet and arms.
Here goes... what I'll be doing is documenting the creation of what intends to be a backpack for my 'puter.
The things I want is stylish *cough cough*, and be able to fit my stuff in nicely, so therefore a padded interior and cut out spaces for components such as:external CDROM, lappy, power supply and maybe a usb hub - with the ports as it's feet claws.. but that is a bit over top and probably won't happen.
The interesting parts- how it starts and how it is being constructed.