foam in front hood cavity

[TheSecondChris]

There's some yellowish foam type substance in the forward cavity of my hood. Car is 1987 951. This seems to be a little strange, so thought I'd check if others have the same.

[Monkey Wrench]

mine isnt' that new so maybe its OEM but likely someone just sprayed expanding foam in the cavity, perhaps to quieten ..

possibly it was used in a repair strategy .
as an example My brother had a triumph , added different carbs, cut a hole int he hood for clearance, then he wanted a bubble.. so he shaped pour in place foam to get his desired teardrop shape then applied fiberglass overtop.

it can be used to hold insulation in. I stripped my antique living room walls which had no insulation. I cut ISO board, which is basically the same substance. made them fit each stud bay loosely, put plastic overtop and strips of lath to hold insulation tight in wall cavity. sprayed expanding foam between each stud. when dry removed lath and plastic and trimed any ooze out with a box cutter. wall is then very tightly insulated. Its basically the same thing as crazy glue , wont stick to soft plastic but sticks like crazy to anything else, including your fingers. getting any off your fingers is the same situation as getting crazy glue off your fingers. I think its the same thing but foamed up with a gas. the gas expends the foam when released from the can, and it quickly hardens up.

a concern may be that if water gets between metal and spray foam it may creep along, but I think it is closed cell so shouldn't absorb moisture. if it's dirty , not stuck well, then capillary action will draw water in there and cause rust. If its clean and stuck it may not be a big issue.

could be an attempt by someone to solve a problem with a wasp nest , or similar.

one may add a hood quiet kit and use that to hold the foam board in place permanently. Perhaps a sort of quick and dirty way to do it, but possible.

[icb]

I have it in my 88 944S hood. Just in the front edge. I thought it was strange too.