So I used weatherstripping for air conditioners for the ducts but what do you guys think about using closed cell foam for the AC and heater lines where they seal against the firewall

 

I used 1/2 Inch Wide X 1/4 Inch Thick, Neoprene Weather Stripping High Density Foam Tape
for the blend door seal and around the firewall opening... worked fine.

 

Did you order it online or did you get it in a store?

 

A place i used to work at had closed cell sponge rubber neoprene with super sticky adhesive on the back(all thicknesses). I used that, It will out last the standard foam you can get at the home improvement stores. When i took my hvac box apart all the seals where shot.

 

Got mine from Amazon.

 

That's The issue with mine. To bad you didn't know the name of it

 

Thanks man

 

I stripped all the old stuff, wiped it down with alcohol, and stuck on my precut piece.

 

How did you do the firewall seal for the AC lines and heater hoses? Just layered it on top of one another?

 

Just did strips placed snugly together and trimmed around the edge.
You can use some rtv or seal adhesive between strips if you want to be certain it’s sealed.

I didn’t use any sealant, and it doesn’t leak.