Thursday, July 31, 2008

Molds, Molds, Molds...

And here begins the plaster mother mold section of the moldmaking process...

First you need:

Mold1 025

Lots of burlap cut into squares. Check.

Mold1 022

Lots of vaseline. Check.

Mold1 030

And lots and lots and lots and lots of plaster. Check...oh wait no we ran out and had to order more midway through...but we got it so Check!

Mold1 033

After applying a thin coat of vaseline to the rubber, metal and the base, we mix up a bucket of plaster. We've been doing 16lb mixes at a time, as its seemed to be enough for both of us to use and not run out of too fast yet it doesn't set up before we're done.

A little about the plaster, we're using a mix of FGR and pottery plaster (Usually we use molding plaster instead of pottery plaster but they seem to work the same). We dry mix it first and then use a 1:3 ratio for water to plaster (4lbs water:12lbs plaster). We add the plaster to the water, let it soak in for a little while and then mix it using a mixer on a drill. (Using the mixer gives you a nice consistency.)

We then use brushes to paint up the first coat of plaster (as seen above), staying within the shim of section we're working on. At first the vaseline resists the plaster a bit which is always a pain, but as it thickens it stays up.

Mold1 034

Closeup of splash coat being applied.

Mold1 035

Then we go in for a second coat, where we coat pieces of burlap with plaster and over lap them across the whole ends up looking like a terribly uncomfortable patchwork quilt or something like it...

Mold1 036

In this photo you can see a bit of texture difference between the area with burlap (the bottom half) and the area with just a splash coat (the top half).

Mold1 037

We then go in with another coat of burlap over the whole thing. After that, we further build up the edges of the section of the mold using more burlap and thickened plaster.

Mold1 038

After starting the 2nd side of the mold.

Mold1 039

2nd side with splash coat.

Mold1 040

Here you can see how we end the plaster at the clay wall. Before working on the piece to the right, we'll remove the clay wall and vaseline the plaster edge of the first piece so the two pieces don't stick to each other.

Mold1 042

Working hard...

No comments: