Deve, if you're using a new rad and 4# cap [could use 7# with a new rad] you won't have any overflow to catch as long as you do not overfill the rad and the system works as designed
"When we tug a single thing in nature, we find it attached to the rest of the world" ~ John Muir "When we tug a single thing on an old truck, we find it falls off" ~ me Some TF series details & TF heater pics