I made my second moulage mold this past Friday, but I didn't have a chance until now to post about it. I have learned so much about using moulage and I am still very excited about using it to make my molds.
I have also made a more detailed instruction for making moulage molds.
I am still using a large pot with my glass jars of moulage put into it. Water is made high enough to cover the majority of the glass. I brought the water to a boil and then set it on low for the remainder of the time. After the moulage was melted enough I poured into my mold. It was still a little lump, but that made no difference to the end result. In the future I plan to get a spatula so that I can smash larger chunks to help it melt faster. That should cut down some of my time and make the moulage smoother.
Above you can see my molds. One is for a pair of legs and the other for a pair of arms. I decided to try making a one piece mold for them. You can see the oil clay at the bottom of the mold shells (which is plastruct) to seal any cracks. You don't want to pour hot moulage in and have it pour back out.
What I found was when the moulage was cooled to 105-110F that the jar was not too hot for me to hold. Your sensitivity may vary though.
I covered the moulage molds after pouring with some plastic wrap and left it alone for 2 hours.
When I came back in 2 hours my moulage mold was set. I tried to cut the sides the best I can, but when you are working with an opaque material it can be a bit difficult. So there are times I will prefer the multi-part molds instead of a one piece mold. Some cuts I failed and had to retry because where I made the cuts didn't help release the original still trapped inside the moulage mold.
The first pour of hot carving wax into my leg mold showed pour issues. The mold was probably still too cool compared to the hot wax. But each pour of carving wax after was just fine. So I can assume you may need one junk cast before you get better results. The moulage mold for the arms, however, was fine on the first pour.
I had a problem getting my cores hollow at the start, but once I got a sequence going it worked out well.
Here is what I did:
1. prep leg mold and pour hot wax.
2. wait a few seconds and pour out hot wax from legs
3. place leg mold on counter with wax in it to cool.
4. prep arm mold and pour hot wax.
5. wait a few seconds and pour out hot wax from arms
6. place arm mold on counter with wax in it to cool
7. remove wax legs from mold.
8. remove wax arms from mold.
And repeat the bold section.
Here are the carving wax legs I got. The far left is the original. The second from the left is my first cast and you can see at the top of the leg where the pour issue was. But each leg after that was just fine.
And here are the arms. The ones with the beads are the original.
The arms did not hollow as well as the legs because of how thin they are. I tried poking the hole with a stick but that ended up causing flaws in the sculpt so I had to stop that. Tapping the mold doesn't help either if the wax is hot and can cause distortion in the wax being cast.
All in all, I think my second try was much better than my first. I think I will be even better on my next try. I will be selecting the best 3 for each limb and melt the excess back down. Of the 3 I kept, one will be used to make the joints for those limbs. The other 2 are if I make a mistake and need to try again or to just keep a record of what I did.
I made an instructions page for making moulage if you are interested. It is a lot of text though. Later I will make a simplified one with pictures.