Carthagenian

I read a science fiction story, maybe 15 or 20 years ago, in which they used small ballons to find and temporarily block small punctures. The escaping air just pushed the drifting balloon over the hole and air pressure kept it blocked. (In fact I remember another story in which vast numbers of people migrated off Earth to live in orbiting inflatable spheres with complete and closed ecological systems, a sort of space 'farm' if you will) I'm new here and a non-scientist, but it seems to me it doesn't take much of a patch to seal in air at 15 pounds per square inch. I also remember in Aliens 4, the monster was sucked out into space through a fist sized hole in the hull. I'm thinking human skin, let alone alien armor, can stand up to 15 pounds per square inch well enough that there is no way a person or monster could be sucked through the hole. I'm thinking they might get a hicky or burst blood vessels in the skin. Any engineers out there, or maybe a doctor, who know what hard vaccuum over a 3 in diameter area does to a human being? Is it crack crunch splort and out into space thing, or more along the line of 'ok, hand me that metal plate to put over the hole before I need a skin graft here' kind of thing?