Insulfoam

Insulfoam is a material used often in space habitats, it's one of those 'spray and forget' type substances that serve a variety of purposes. It insulates pipes, stops up exterior holes until more permanent repairs can be made, and keeps the space between habitat seams airtight. The spacer version of duct tape, it starts as foam and hardens into rock-like permanence when exposed to air. Comes in a variety of colors.