I grew up in a dental clinic. Both of my parents specialized as orthodontists so I grew up seeing how they manufactured braces and retainers for each patient. Though they’ve finally switched to new techniques of 3D scanning and SLA printing, I still remember the horrors of pink alginate and moving casted models of teeth.

Molding and casting by myself this time was much easier than I once imagined the process to be, but just as messy as I once thought. Both processes were simple, the only slight hiccup was the timing for demolding the cast. The alginate powder was mixed in a 1:1 ratio with water and left to set with a finger in it until it had a gelatinous consistency. The plaster was mixed with water at a 2:1 ratio with slightly more plaster added while continuously mixing if the initial mix was too fluid. It was important to stir continuously to cultivate a homogenous mixture and prevent setting. As soon as the fluid showed a change in viscosity, the mixture was quickly poured into the alginate mold and tapped on the side to agitate and remove any air bubbles left from the pouring that would compromise structural integrity. A screw was inserted inversely into the cast so the finger hook can be screwed into a wall.

 

 

 

 

 

 

Initial versions of the cast were allowed to sit too long and ended up crumbling or breaking when demolded due to moisture absorption from the alginate which compromised cast integrity. The sweet spot seemed to be demolding the cast around 1h after the pour. To do this, the mold was cut to enable easy demolding. Future pours could still be repeated by simply rubber banding the alginate mold to prevent leakage and the finger was done after a quick spray paint.

 

 

 

 

 

 

The annoying part of the project was cleanup from the mixing. The alginate was easy to clean up since it congealed into an easy-to-peel piece after drying, but the plaster took some serious scrubbing to get off.

Cost Type	Cost	Price	Source	Quantity	Total
Materials	Alginate	$0.70/oz	Dickblick.com	2.65 oz	$1.85
	Plaster	$1.94 /lb	Homedepot.com	0.09 lb	$0.17
	Spray paint	$6.19 /can	Target.com	1/10 can	$0.62
Labor	Molder/Caster	$15.75 /hr	Recruiter.com	1/4 hr	$3.94
	Spray Painter	$17 /hr	Ziprecruiter.com	0.25 hr	$4.25
Total					$10.83