fiberglass and resin, leaving a gaping hole in the board. He fastened a patch for the hole from some epoxy glue; Araldite is the brand he used, but any two-part epoxy, like JB Weld, should work.

Practical, no doubt, but pretty unsporting, especially when it’s possible to cast custom lenses at home using silicone molds and epoxy resins ... while he was working on these casting methods.

BASF and Sika have jointly developed a new amine building block for curing epoxy resins, which is now commercially available under BASF’s Baxxodur® EC 151 brand.