Wednesday, November 21, 2012

Mold-making, Casting and Masks!

In preparation for Mask-making next semester, I am taking a course on mold-making and casting. Awesome! We first learned how to use a simple two part putty mold-making medium. This is used a lot in jewelry making -- that's where I've encountered it before. It's a great way to make a simple mold. All you have to do is mix equal amounts of each part of the mold medium (part A and part B) and then press whatever it is you want to make a mold of into the product. You let it sit together for about 20 minutes and then it's set! You can get a surprising amount of detail. I think this is especially nice for buttons and brooches. We then used this mold to make a resin cast. In jewelry making we would often use this type of mold to pour wax into and then cast obviously, a lot of uses and ways to use this type of mold making.

The next mold that we made was a silicone one. Again, you mix equal parts of part A and part B of the product and simply pour it into your mold box, onto whatever it is you wish to create a mold of. I made a mold of a key. The detail for this one was fantastic. I also really liked the silicone -- it is flexible and easy to use as a mold. We also poured resin to make the cast for this one as well.

Next was life casting with alginate. This was a ton of fun! You make the alginate mold for the face with the person sitting up, in order to capture an accurate face mold. You mix the alginate with water and the just start glopping it onto the persons face. They are wearing a bald cap to keep hair safe and away. The also have a tiny bit of Vaseline on their eyebrows and lashes. The alginate mixture starts out like thick chowder or oatmeal in consistency. You continue to pour the alginate over the face and constantly pushing it back up against gravity. You really need to make sure to cover everywhere and get the air bubbles out! We also kept the nostrils clear (important for breathing! ). One the alginate starts to set up it gets easier to keep it on the face. When it stops being moveable you put a layer of gauze onto the alginate to create a link between it and the plaster mother-mold that you will be applying next. Once that is all settled you begin applying plaster bandages on the alginate. It is really important to get the plaster right close to the alginate contours in order to create a stable mold. You continue applying bandages until it is several layers thick. Careful to mind the chin! When it was being done to me, I could definitely feel the alginate wanting to fall off my mouth and chin area. Anyway, then you let t takes about 20 minutes or so. This whole time it's very important to keep in contact with the person under the plaster -- make sure at least one person is keeping  a hand on their shoulder so that they are assured you are nearby! It's a bit scary being under there, completely cut off from light and a bit from sound, with a bunch of heavy plaster all over your face! After it has completely set, the person simply wiggles their face a bit and it pops off pretty easily!

Next step is to pour plaster into the mold you've just created in order to create a positive of your face. We used ultra-cal plaster -- super hard and strong once set. Before pouring you must seal off the nose hole with clay. You can also fix air bubbles and anything else with the clay too. You have to be careful not to futz with it too much -- the alginate can get great detail, including pores, wrinkles, etc. The more you rub it with water and clay, they more you will lose this detail.

So at any rate, my mold turned out nicely. It's not perfect -- you can see where the alginate was falling off my cheek, upper lip, and chin -- but in general, it worked out great for a first attempt! We were working in a group of 3 people by the way, taking turns.

 We will now use this face cast to create masks! Our first assignment is to use plastiline (oil based) clay to sculpt a mask over the face. It has to be bird themed. We will then create a two part plaster mold. Next semester we will use that mold to cast a latex mask.

Here is my bird mask sculpt so far -- it still needs to be smoothed and refined.

The plastiline clay is interesting to work with -- I've done a lot of work with water based clay, but not oil based. It is very plastic! Heat makes it much easier to work with!