Silica Gel Regeneration

The humidity in the basement safe has been on the rise for the last few months:

So I dumped all three bags of spent silica gel onto cookie sheets and baked them at 250 °F for a bit less than 12 hours overnight. As the (gas) oven temperature isn’t all that well regulated, I set it to 230 °F and hoped for the best. I have no way of knowing what the actual temperature was during the night.

The silica gel inside the bag from the safe weighed 583 g and the two bags that had been sitting in the basement air weighed 663 g. After baking, all three trays of beads weighed 496 g, slightly less than the 500 g direct from the factory-sealed cans.

The beads looked undamaged from their ordeal.

Two dozen scattered beads collected from the countertop and floor weighed 0.4 g, for an average weight of 0.017 g each. I definitely didn’t lose 12 g of beads during this adventure!

The translucent white beads vanish against an off-white laminate kitchen floor under ordinary lighting. They’re retroreflective enough that peering along the side of an LED flashlight lights them up; I’m pretty sure I got most of ’em.

Memo to Self: Next time, try 6 hours starting in the morning.