Air Conditioning - A/C Lines sweating and their insulated. Leaking through insulation on lines

My A/C unit has well insulated lines going to the coil ( I guess that's what it's called) There's 2 lines going to the box above the furnace and there's coils in it. One of the lines is well insulated with a foam type insulation, the other is not. The one that is insulated has spots leaking from it form the condensation, it seeps through the insulation and then runs down to the coil, then through to the floor under the furnace. (My lines are in the basement, and they are run through the ceiling in the basement, which wold be the floor joists for the main floor. The problem is the lines are leaking through onto my finished ceiling in the basement. Then the condensation runs "downhill" to the coil, then leaks all over, how can I cure this? The insulation is a tube type insulation that is form fitted over the , what looks to be copper tubing. It makes a real mess. Any suggestions would be great. I'm a single mom with 2 children and can't afford to have someone look at it. Thanks, Juli

First Id ask is the big copper line cold and wet where it goes into the outdoor unit??? If so then there is a presstite cork insulation tape that you can add over that black foam that you now have on the line there. You sure the air filter is clean . blower clean freon ok no ice or frost on the line by the coil??

ED ;)