Stopping Air Infiltration at Cable / Phone Line Entry
 

I have an entry point for cable TV coax, phone lines and a couple of grounds. There are about 8 Coax cables and 8 phone lines. They exit the basement of the home through a hole drilled in the poured foundation.

The air infiltration at this opening is significant. There is effectively an open
path to the outside between every cable. They fit pretty tightly together but if you flex the cables a bit you can see sunlight.

I'm struggling with how to stop the airflow. My first thought was expanding foam but that could be a mess and not guarantee that the leaks would be filled.

I searched the web but mainly came up with industrial products for outdoor utility boxees.

Any suggestions?

Thanks for your help,

Johnny

silicone?

all of my wire entries are siliconed on the outside to stop water but it's effective against air. do outside and inside and you should be fine.

expanding foam is your best bet, sticking the straw of the can in to the center of the bundle in the center of the hole so it is expanding both directions is most likely going to give you the best results.
If it was a new hole, putting a chunk of pipe in the hole with a rubber cap at each end then drilling a small hole for each wire would be a good way to go and you might even want to add a small pipe/tube to your current hole just so you can add new wires at a later point in time, you should also make sure that you don't have any extra unused wires that should be pulled out before doing any sealing.
If you don't want to use foam, you can also also use caulk but it's not going to seal as well, also if you are worried about the foam expanding enough you can wet the area with a spray bottle as the canned foam tends to react with water to make it foam so a little water in there will make it foam and fill even more then normal.