Heater Core Insulation

[gilber33]

I stupidly threw out the old heater core before cross referencing where the insulation needs to go on the new one and now I have this gap at the bottom of the heater core. I assume there is supposed to be a strip of insulation along the bottom here?? Can anyone confirm? And if so, since I used the little bit I go on the behr unit, what can I use in its place?

[roguetoaster]

What typically comes with heater cores is a small piece of closed cell self adhesive insulation, so whatever you can find at the hardware store will probably work to fill the void.

[gilber33]

What typically comes with heater cores is a small piece of closed cell self adhesive insulation, so whatever you can find at the hardware store will probably work to fill the void.

If that’s all it is then no issue getting some and filling the gap. I didn’t know if I was missing some specific seal or if there was more to it that I didn’t have.

thanks