So if you are looking for a strong insulation, a closed-cell spray foam is what you want to grab. As for smaller fill-ins, an open-cell foam will do just fine. The post The Difference Between Open ...

Half a gallon of wood glue, a pile of random, scattered resistors, or in [Ken]’s case, closed-cell silicone foam. Wanting to avoid this situation he set about trying to make his own silicone ...