Okay, so I tested a new high definition alginate on my friend Kate today. I'd experienced it myself twice now, the second time issuing the instructions while I sat trapped covered on goop. Should be easier this time, right? Wrong! Or at least, not as straightforward as I'd hoped. Let's just say my attempt was a learning experience, and hopefully, you can learn from my mistakes.
I was all excited, laid out my materials, and then came the dreaded water-to-powder ratio. The instructions were American and I made the fatal mistake of referring to old instructions when it came time to measure. Just goes to show multi-tasking and hand casting doesn't mix. I mixed 200 grams of alginate powder with 600 ml of water. Big mistake. Huge. It looked… thin. Like, really thin. Panic started to set in. Then it hit me, it was meant to be double the amount of powder to water, so we raced to measure another 100 grams and mix it in. Still a bit runny. Turns out, I had been provided with 2 sets of instructions and the correct ratio was 200 grams of powder to 200 ml of water. Facepalm. My alginate was definitely on the watery side, which, as I discovered during de-moulding, led to a very thin mold.
I persevered, though. I mean, I'd already made a mess, might as well see it through, right? I carefully applied the goop to Kate's hands, trying to keep her skin continually covered while this… goopy mixture slowly set. It took longer than I expected, probably because of the incorrect water ratio. Finally, it was starting to set to a custard consistency so I could apply the plaster bandages to make a support shell.
Next up: the plaster bandage part. This is where I knew things could go wrong from my second experience. I knew last time the plaster had not been smoothed out enough with water which left holes in the fabric of the bandage, so I diligently smoothed the wet plaster bandages and applied a bit more warm water with my fingertips to seal the holes. Good tip, that one, because it definitely helped create a smoother plaster shell. Something surprising though, the heat the plaster generated was insane when it had set. You could fry an egg on the heat emanating from Kate's hands!
Then came the moment of truth: pouring the stone. I hesitated when it came to trimming the excess alginate from the back of the hand mould. It seemed to be supporting the sides of Kate's fingers, and I was worried about damaging the mould, so I left it as it was. Big mistake number two! When the stone dried, the alginate was embedded in it, creating a lumpy and uneven back. I managed to carefully remove the alginate with my detailing tools, but it doesn't look as neat as I'd hoped. You really have to work fast with the plaster stone. This time, I got smart and used my fingers to carefully push the stone mixture into the thumb area, and I actually managed to preserve the fingertips! They aren't perfect, but the detail on Kate's hand is amazing. I'm very impressed with this new alginate despite my initial struggles!
The whole process was a bit of a comedy of errors, from the runny alginate to the over-plastering. But you know what? I ended up with a cast, albeit a slightly wonky one. And now I know what not to do next time. Hopefully, my experience will save you from making the same mistakes. Just remember: the water-to-powder ratio is KEY! And don't be afraid to experiment, but maybe do it with smaller batches first! And no Kate, you don't have witchy hands!
