The refrigerator. This appliance was surrounded by a tight enclosure, making access tricky. Luckily, there was a return-air grill right behind the refrigerator. I was able to drill a hole in the floor joist, using a 1/2" drill bit. Down in the basement, I used a hole saw to drill an oversize hole, hoping to fish the tubing through. I pushed the tubing through the first hole, trying to find the second hole. My objective was to avoid removing the foil/cardboard material that covered the joist bays to form the return air duct. But I was unable to fish the tubing through within five minutes, so I removed the duct covering, which was held in place with staples. With the return-air duct exposed, I was able to quickly fish the tubing through the holes. The block of wood was the source of my earlier problems. The valve was attached to a clean section of copper pipe (cold water line). The piercing point must be fully retracted or a sudden leak could develop! Using a small wrench, I turned the valve body slightly, to point in the right direction. The nut was slipped over the tubing, followed by the ferrule. The tube was inserted into the valve. The ferrule gets squeezed between the nut and the precision-machined valve body. The compression nut was threaded by hand and then tightened with a small wrench. The valve handle was turned all the way in. The sharp point punctures the soft copper pipe. When the valve is opened, water will flow. I finished running the tubing. The refrigerator is just behind that hole. There was a plastic cap over the water line connector on the lower rear of the refrigerator. The compression nut and ferrule. As before, the tubing was slipped in and the compression nut was threaded on by hand.. At this point the ferrule is loose enough to slide along the tubing. After the nut is tightened, the ferrule will be compressed onto the tubing, never to move again. The nut was tightened. Pipe dope is not needed on compression fittings. The completed connection. The white plastic tube runs to the freezer compartment. Behind the shiny steel plate is an electrically controlled water valve that lets water fill the ice trays.