This insulation foam trick went wrong after only 3 days in my garage

I saw this idea online where you spray the expanding foam into a trash bag to make custom shaped packing support. Tried it myself last Tuesday, let it cure for 24 hours like they said, and it looked perfect. By Friday morning the whole thing had crumbled into sticky chunks that smelled like a chemical spill. I'm wondering if anyone else has found a way to make this actually work without it falling apart?

3 comments

3 Comments

casey_barnes7d ago

Actually "window and door" foam is usually closed-cell too, it just cures slower than the big gap filler stuff.

jason_stone127d ago

Tbh @casey_barnes I always thought that stuff was open cell, good to know I was wrong.

susan_ward19d ago

Oh I tried that same trick last year... ended up with a mess just like yours. What actually worked for me was using the low expansion foam instead of the regular stuff, the kind that says "window and door" on the can. I also gave it a full 48 hours to cure and kept the bag in my heated basement where it was around 70 degrees. That batch held up for months without crumbling.