Hi everyone,i came across some doors on craigslist...so i made some half doors.......Now before i close it up and weld,i wanted to see your thoughts on insulation.....or packing the inside with that stuff you can get at home depot (Dont know what its called) its in a spray can....when sprayed it starts expanding.....and when it dry's its like hard foam.....im not to concerned about insulation weather "wise" its just when you close the door its sounds really "hollow"