REPROGEL: A Cheap-O Casting Adventure! [p02]

First attempt.

For less than a dollar, I got a 1kg bag of what looks and feels like cement, except it has an orange hue. According to what I've read, gypsum is used for casting; the clerks at the shop though referred to it "cast stone". They were unable to provide a specific mixing instruction and was simply advised to play it by ear, err, eye.

Not exactly helpful.

For this attempt, I tried to get the consistency of concrete. Here are the results so far:

I mixed roughly 200g (too much as I had to throw away the excess - first pic) for the FG's foot and Kenny Roberts' head.

Results: the foot looks promising as the details can be clearly seen, but the head leaves a lot to be desired.

Looking at the head, it actually gives me the willies. Looks like a rotting zombie head. :P

Observations:

1. The material hardens in as fast as fifteen (15) minutes, although I had it sit under the sun for an entire day just to be safe.
2. Once hardened, the material has the feel and hardness of concrete (i.e. sand and construction cement) and even gives a "clink" when dropped. No chipping. So far.

Concerns:

1. Since I do not know the exact composition of the material, I cannot confirm it's toxicity. (Gypsum is supposed to be non-toxic.)
2. Like Reprogel, it has a quick setting time, so bubbles are a problem. I'll try thinning the mixture next but I doubt if it will do the cast good.
3. Reprogel whilst moist, wasn't exactly pliable. I had a hard time prying the foot off [the mold]. After being exposed to the sun for a day, the Reprogel mold became dry and crumbly. So reusable molds just went out the window.

REPROGEL: A Cheap-O Casting Adventure! [p01]

Ever since I got serious with plastic models, I've always tried to keep the expenses low. One of the things I've been keeping an eye out for was how to cast manipulators without having to use resin. A week ago, inspiration struck: denture casting. If this works, I can definitely say it's not just affordable, it's down right cheap!

Dental technicians use Reprogel to create a mold and gypsum for the cast. Reprogel comes in powder form and in 21-gram packs that needs to be dissolved in water. Once it solidifies, you'll have a mold that feels and behaves like the eraser at the tip of a graphite pencil. I was able to produce a Reprogel "patty" about half an inch thick and four inches wide (diameter). I decided to run tests to see if it's feasible to use it for molding and casting small items.

My goals were pretty simple:
1. See how much detail can a Reprogel mold hold.

2. How plastic reacts Reprogel.

The first photo shows the Reprogel "patty" with the molded head (half a head that is, as I only used the face). I also tried using an FG Sword Impulse's foot which I made a mess of while extracting the original.

Pros:
1. Relatively safe: it's made of food grade gum/rubber resin.

2. It's dirt cheap: a pack is less than $0.25 cents!

3. Smells good: comes in cherry flavor! :P

Cons:
1. You only have a 30-second window before Reprogel hardens.

2. Bubbles are prevalent as you have precious little time before Reprogel sets.

What I want to find out now is if there's a way to retard Reprogel's setting time.

Next: casting call!