Science Workshop
Enlarging Casting Resin

HydroSpan 100, from Houston-based Industrial Polymers Corporation, is billed as “a 3 dimensional copy machine enlarging any shape or design in near perfect proportion and detail.” Shown uppermost, a Morgan silver dollar from 1896, enlarged via three generations of HydroSpan 100 casting to about the size of a salad plate. To use it, two components are mixed and poured into a conventional silicone mold. After curing for 24 hours, the resulting casting is soaked in water for a period of several days, swelling it uniformly to 160% of its original size. The enlarged casting can then be remolded and the process repeated as many times as necessary to achieve the desired final size. Industrial Polymers also manufactures a shrinking casting resin if you want to go down the rabbit hole, instead.

6 thoughts on “Enlarging Casting Resin

  1. I remember seeing this at the Compleat Sculptor a while back; they had some samples and examples out on their sample table. It looks like pretty cool stuff, making much more accurate enlargings and shrinkings than the old “let your alginate mold sit for a few days” shrinking trick. Unfortunately, they were not selling any “trial-size” kits, and spending $85 for 3 qts just to play with was out of my budget at the time.

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I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

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