Under cowl foam seal

Morning, I’m sure I’ve seen this post before but can’t find it. I took my cowl out ages ago and like an idiot I glued my new hood to cowl seal to the firewall, not thinking about reassembly .

Fast forward to today, I bought screening to glue to the underside of my cowl slits but I still haven’t found a good replacement for the foam under the cowl and I’d like to reassemble it today. I’m worried the super soft foam from Home Depot for weatherizing might soak up water and cause more harm? Also, it seems to glued to the cowl and to top of the firewall. What have others used? Is there an auto purposed foam for this purpose?

Garage door bottom seal.
If it can sit in slush and rain for years, it can keep water out of your air cleaner.

Frost King and MD both work fine.

Contact adhesive or 3M weather strip adhesive to seal it to the cowl.
You could also use Household Goop or Shoe Goo.

I think you’re thinking I meant the actual hood to cowl seal (?) which I have (bought from bronco graveyard- expensive but seems high quality for anyone in a similar boat). But regardless I’ll prolly try some rectangular/ squarish foam insulation unless a better idea comes along.

I am meaning that.

Are you talking about the heater plenum seal?

Closed-cell foam doesn't soak up water - it's the correct modern replacement for the original junk.  Read this caption and the PREVious/NEXT several:

Oh ok, sry was having a hard timing visualizing it. I was thinking the foam would need to be thicker to fill the gap but looks like it’ll work! Thank you both :)

Funny you asked this as I just did this on mine today.
I used the closed cell foam you get at the big stores, Lowes for me here.

There was the outline of the old one on the vent so I followed it.
I was thinking when I pulled it off the roll it had paper still stuck to it that is had glue on both sides of the foam. It does not the paper is so it will not stick to it's self when coiled on the roll.

BTW that cowl vent to fire wall seal as I would call it is so heat from the engine bay and any fumes do not get into the cowl and in to the cab of the truck.

The firewall to hood seal kind of does the same but also keeps water off the back of the motor when it rains or gets washed. This is where the garage door seal is used.
Dave ----

Late in reply but...
Use the black neoprene tape intended for refrigeration lines and pipe wrap.
It's conformal and closed cell.

And yeah, buying a hood seal is stupid expensive when a $10 garage door seal will do two trucks.

Just reporting back - i ripped off my new hood to cowl seal since I stupidly adhered it to the wiper valance piece/ “under the cowl” area. ( my cowl had been off for quite a while). Rubbed the cowl with cutting compound then polished, and then cut plastic window screen to the underside and used window weatherstripping from Home Depot. The thickness was a big worry for me, I ended using using a closed cell foam that was 1/2 inch thick and might have been a smidge too thick.  Got the cowl in but it’s a tight fit. The foam adheres on one side - I stuck this side to the cowl and didn’t bother applying gasket sealer to create a seal between the foam and the valance. I figured that would just make a mess with no major benefit. I reapplied my now slightly warped hood to cowl seal with some gasket sealer. Looks good, hopefully it holds up. I noticed I have a leak in the cab after our first rainstorm and that may mean I’ll take the cowl off again at some point but I just needed it done. I may apply gasket sealer around the antenna too as I doubt the old black plastic base is soft enough to seal out rain water anymore.

Thanks for the follow up.  Hope it doesn't leak.