We're going to use the alginate to take an impression. This kit came with dental grade alginate, which has a very refreshing minty flavor.
Make the impressions one tray at a time. They only take about a minute to set up, so there's really no point in trying to do both at once and risking failure due to uncontrollable gagging. Just trust me on this.
For one tray, you'll want to mix up:
Two tablespoons of alginate with
Two tablespoons of room temperature water
The temperature of the water will determine how quickly the alginate sets. The warmer the water, the faster it sets. Room-temperature water is perfect, even for beginners. This gives you about 30 seconds to mix, and 1 minute to set.
Mix the alginate well. It will have the consistency of cake frosting. Fill the upper tray with alginate and fit into the mouth so that the teeth float in it, and don't touch the edges. Make sure to get the upper lip out of the way so the alginate can take a full impressions of the gums as well. This took me about three tries to figure out.
You can tell when the alginate is set by looking at what's remaining in the bowl. Once it's set, it's pretty likely that what's in your mouth has set. Since the alginate takes an exact impression, it creates a vacuum when trying to take it out. Just press on the edges and wiggle it to break the seal.
Repeat on the lower teeth. Make sure you (or your subject) lean forward while taking the lower impression so no excess alginate can flow out of the tray into the mouth and throat.
** If you're someone with a sensitive gag reflex, remember to breathe through your nose, and hold a paper towel to your mouth to absorb the saliva. Taking the lower impression made me slobber like a dog for some reason. This isn't really good 'first date night' kind of 'fun thing to do together' material.