My Adventures In Mold Making

I'm going to try to explain the various and still not final methods of how I made my molds, I'm going to explain each one per project. This is for anyone who doesn't want to buy a mold, or want's to make an original shape. These are all ideas that I came up with over some time and experimenting. I'm mainly sharing this info here, because I believe the Internet is a good source of information, and when I was looking for how to make a mold I couldn't find anything.

THE HEART OF ATLANTIS
This one used a Styrofoam-like substance, the flaky crunchy kind.

For the lid, I used two forms. The first was a rounded heart, the second a flat heart. I glued the two together and sculpted the lower heart to round it off. I then sprayed the mold with white spray paint to seal in the flakes of the Styrofoam. After that I covered the whole thing in clear packing tape, and traced on my lines.
After the lid was built, once I knew that this method would work, I made the mold for the base. I glued two 2" sections of the foam together, trimmed off an inch and shaped the heart. I had to make sure the roundness of the sides were fairly even. I then sprayed the whole thing with spray paint to seal in the crumbly texture of the Styrofoam. I then stuck the tape on the entire mold. For this project I had to be sure to cut the mold in half so I could release the project after soldering.
Then I traced the lines out on the mold. BTW this was the only pattern I had to work from. Basically, I held up the glass against the mold and traced it onto the glass. For this particular project it wasn't terribly hard to do because of all the straight lines it had. However, next time I'll probably take the time to make a flat pattern first. This step took a while to do because I could only cut out about 5 pieces at a time. The sides of the box has approx. 300 pieces in it.
I used double stick tape to hold the pieces onto the mold. After I had enough pieces on the mold to cover the height, I took thin strips of masking tape to hold it onto the mold to keep its rounded shape.
To remove the sides after soldering, I used denatured alcohol and squirted it into the sides. and then carefully pried the sides loose.

NOTES: This first mold did work out and is still the basis for the other molds I've made. However the paint I used ate the Styrofoam and besides reducing it's overall size and shape, it now has a much more lumpy texture to it.

HERSHEY KISS BOX

I did the same steps as before, only this time instead of sealing it with spray paint, I used acrylic paint to seal it. And with this kind of paint I was able to shade it the colors I wanted. When I made the heart it was all white looking, and I had to know where I wanted the color to be.
Then I covered the whole thing in tape like before (so I can trace marker around it).
Then did the same thing with the double stick tape.

NOTES: This one did come out better than the first one did because this time I could see where the colors were, and my mold didn't melt.

APHRODITE'S TREASURE (FISH LAMP)

I had to glue about 6 sections of foam together to make up the height of this thing, and another one for the width.
Cutting something of this size was very tricky. The foam just isn't very easy to cut when it's that thick, especially when you're trying to cut a particular angle. I wound up using a cross cut saw and a mirror because I couldn't see the other side. Needless to say it was difficult. They do sell a hot knife for this kind of foam, I just don't have one. A large band saw would also work, but I don't have one of those either :(.
This time, instead of using any kind of paint, I used plaster of Paris to seal the mold. I put on rubber gloves, and smushed and rubbed it into the pores of the foam. Once dried I lightly sanded it.
After the first sealing layer was on, I then coated it with more plaster, trying to level off the low spots that I accidentally made when cutting the foam. The problem was that the plaster kept absorbing all the water as I put more plaster on.
After all the layers of plaster were just about dry, I then Surformed it (from my auto body training), in which I grated down the semi dry plaster to make it more level. When the plaster was completely dry, I sanded it to be as smooth as possible.
I then blew everything off, marked my center lines down the center of the mold width wise and the center of where each panel was going to be.
Then I sealed the plaster in with a clear polyurethane spray giving it a couple of coats. The other important step that I forgot to mention was to make a hole on the top of the mold to insert a rod wide enough to help center the cap when I would be up to that step.
I then marked the top of the mold where the cap was going to be.
After I made up my patterns on paper, I traced each section onto the mold with carbon paper, and then retraced it with marker.
Then I coated the entire mold with Acrylic Gel Medium to seal in the marker, so that it doesn't wash off when I remove the glass after soldering.
Then I painted up all the pieces on the mold with acrylic paint. Usually I use crayon to color in my designs, but with the paint I was able to get a more exact look to what I wanted my glass to look like.
When I was up to the glass cutting part, I sprayed the mold with spray adhesive. After cutting and foiling a certain amount of pieces, I soldered the pieces on the mold, then started the next batch of cutting. The pieces were very tiny; some of them as small, if not smaller than, a pencil's eraser. So soldering was a must; the pieces kept falling off otherwise.
When all the tacking was done, I was able to solder the whole thing. And secure the cap, using that hole I made previously to keep the cap centered in the hole.

NOTES: So far, I liked this method best, mainly because of the plaster part. It gave me a hard, durable, smooth surface to work on. However I will NOT use gel medium again as a sealant. I would probably use more spray polyurethane, because I found out that flux and alcohol dissolves this stuff, and when I went to remove the mold, I couldn't. I had to hack the mold to pieces in order to remove the mold from the lamp. It took me over an hour to destroy a mold that took me over 2 weeks to make. How could I destroy something that took that long to make? I decided that since I wasn't going to make another one of these lamps again anyway, I really didn't need to keep the mold. It would have been nice to have it but I thought it really wasn't worth sacrificing the shade for the mold. So I had to carefully cut and remove sections of the mold. I went down about 3/4's of it and was then able to remove the rest of the mold. In some areas of the lamp there were drip through's that helped hold it on.

I tried so many methods to remove that mold from the lamp these are the ones I could remember: