Casting Quick Links Casting Quick Tips

 

Casting

Like the molding process, casting with latex is messy! No matter how careful you are, you will spill some. Every now and again, youíll spill a lot!

Also, liquid latex rubber stinks! I canít stress this enough. It stinks. Bad. If youíre casting indoors, make sure youíre in a well ventilated area, or else your house will stick. Bad.

These are two reasons why I prefer to do my casting in the garage. Iíve cast indoors in the past. Iíve ruined a carpet in one house, and clogged a sump pump in a basement in another. Since I have moved my casting operation into the garage, Iíve had a few spills, but no worries!

One quick warning: Donít let latex freeze! If it freezes, itís ruined, end of story.

 

Process

Step 1 - Coloring Latex

As I mentioned in the supplies page, latex doesnít have to be colored. This is something I prefer to do for two reasons: 1- I almost always begin the painting process by painting my masks black. By starting with a cast that is tinted black, it really speeds up the process. 2- Black latex inside the mask looks cool!

I use Monster Makers Black Latex Colorant. A little goes a long way! Seriously, an 8 oz. bottle will color many 5 gallon buckets of latex. Don’t add too much, or your latex will dry with a glossy finish! After adding the colorant I mix it in with my trusty drill and mixer.

If you only have a 5-gallon bucket of latex to start with, donít colorize the whole bucket. Keep at least a gallon in a separate container and leave in un-tinted and raw, youíll need it for painting and finishing.

Step 2 - Moisten the Mold

Before putting any latex in the mold, I like to moisten the inside of the mold. I do this by quickly filling the mold with water from a 5-gallon bucket and then dumping the water back into the bucket.

This helps the latex get into all the detail areas easier. Latex has a hard time coating fine detail if the mold is bone dry. Youíll end up with lots of air pockets and lost detail.

Step 3 - Detail Coat

After the mold has been moistened, I will pour 1-2 gallons of thin latex and slush cast the inside of the mold. To slush cast means that the mold is not full of latex, so we tip and twirl the mold around until the latex has covered the entire inside surface.

 

Step 4 - Remove Air Bubbles

Next, I pour the latex back into it bucket and use my airbrush to blow out any trapped air bubbles, and to force the latex into all the wrinkles and details. Take care, especially in areas like ears, teeth, horns and such, as these can be tricky areas to get latex into. The airbrush will help make this a lot easier. I tend to this with about 40psi.

Step 5 - Dwell Time

The next step is to fill the mold with latex. Iíll do this with my 5-gallons. Not all masks take 5-gallons to fill the mold. This particular mask is cast with about 3-gallons, it just depends on the piece.

We now let the latex sit in the mold and ďdwellĒ. What happens is that the mold draws moisture out of the latex that touches the mold wall. This begins to form a thin gelled layer of latex inside the mold. The longer the latex dwells, the thicker the gelled layer becomes.

How long is a good dwell time? It depends on who you ask. I like to cast thick masks, if Iím making a wearable mask, Iíll let the latex dwell for an hour. If Iím making a display copy, Iíll dwell for 3 hours. Many times, after the latex is dry, Iíll throw on a second coat. Like I said, I like thick casts!

There are a few disadvantages to thick casts: 1- Youíll use up your latex quickly 2- Youíll chew up the detail inside your mold quicker and get a shorter life out f it. This is exactly why I do very limited numbers for most of my editions.

Step 6 - Pouring Back the Latex

The last step is to pour the latex back out of the mold and into the bucket that it came from. I like to position the mold a top the bucket for a good 10-15 minutes and let the excess latex drip out.

I will than let the mold sit in front of a fan to help the drying process. I tend to let my masks dry a good 24-36 hours before pulling it out of the mold. If you have a nice blacktop drive way, you can put the mold out on a good sunny day and your mask will dry up supper quick, often in less than a day.

Be careful not to let the mask sit in the mold too long or you risk permanent warping. Weíll take a look at this in the next section on the molding processÖ