I wanted to make a mold of a lemon for a project.
Making a mold of a food item has proven to be tricky. I was afraid to make a latex rubber mold, since they take so long to complete, and I didn’t feel like trying to extricate a mushy lemon from the mold in the end.
I tried using a room temperature vulcanizing polyurethane mold making material; the kind that you pour over the item. This went really wrong, really fast [cue $23 mistake-of-the-day]. I didn’t make a proper mold box; I tried to use a modified plastic cup. It wasn’t tall enough to to get 1/2″ of mold making material around all sides of the lemon, so I cut a hole in the first cup, and hot-glued another cup to the bottom of the first. I ended up wasting a lot of material just filling up the areas between the lemon and the sides of the container. Therefore, I didn’t have enough material to cover more than 2/3 of the lemon.
So I ended up with 2/3 of a lemon mold. In the trash.
I was hesitant to try plaster, again because of the mushy-lemon fear, so next time I tried using a product called Insta-Mold. For the first attempt, I mixed it using a spoon. For my efforts, I got a squishy mess, the consistency of tapioca. It kept “weeping” water, and didn’t pick up any of the details of the lemon. I figured I had mixed it badly, and tried again. For the second attempt, I used an electric hand mixer. This time I got…a squishy mess, the consistency of tapioca. It wouldn’t dry. It had air bubbles all throughout.
I turned to the trusty Intarweb to figure out the error of my ways. Perhaps I’d still managed to mix it incorrectly? For once, it turned out not to be me; I wish I’d found this page before I tried using that crap:
Instamold is a terrible product and I do not suggest it for anyone.
Ah. Well there you go. [only an $8 mistake that time]
Plaster it is!
This time, I did actual! research! before attempting to do the plaster mold. I found this page, on how to build an army of Gromits, extremely helpful, even though I was using different materials.
I built a box out of a coffee container. I mixed the plaster super-extra-thoroughly. I placed the lemon carefully in the center, and poured the bottom half of the mold. I added two modeling clay nubbies to act as keys for the top half of the mold. I (patiently!!) let the plaster set. I painted a thin layer of latex rubber over the exposed plaster, then poured the top layer of super-extra-thoroughly-mixed plaster. I let that set up. I braced myself for the gooey grossness of a mushy lemon, and I got…
TA-DAH!!!!
It actually worked. I couldn’t believe it. My husband didn’t quite understand the “I made a mold of a lemon Happy Dance,” but I did it anyway.
…of course, now I’m going to attempt to cast a plaster lemon in this plaster mold, and we’ll see how that goes. I’ve sprayed the mold several times over with resin, so I’m hopeful.