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.