A funny thing happened to Tim’s LEDs while attempting to cast them in resin -

For a project at work I had to mold some things in this hard clear polyurethane, so my Mechie ordered a giant kit of the stuff – more than the project ever will need (and it has a very limited shelf life). So I mixed up a little more than necessary and used the leftover to pot some LEDs.

After some unsavory reaction in a plastic mold tray, he left the resulting mutant to hang dry for a few days. After finally hardening, he found himself the proud owner of the specimens seen above. – Playing with polyurethane casting material [via Ladyada's ranting]