So far I have tried the 5200, but had problems getting it into the holes. I had a lot of back pressure and it did not seem to be going well. So next I tried injecting the Gorilla glue by putting it into empty caulking tubes and squeezing it in to the spaces. I found it is too easy to get too much in and it squishes out when you place weight on top. Then I tried putting some Gorilla glue in the hole and then blowing it with air. I had mixed results. Some area bonded and another area did not. I am sure there is some technique I could refine by talking with Dave. I still had another tube of 5200 so I thought I would try it one more time. What I had noticed with the first try is my caulking gun did not hold the smaller tube very well. The tube pushed out at an angle and the ram was pushing against the side. So duck tape to the rescue, I wrapped the tube in place. Then I cut the tip so it did not go much beyond the otherside of the plastic. You do not want the tip to bury in the foam and not come out. I was drilling holes about 3" apart and found I could put some 5200 in and work it to a further hole. I would put a finger over the hole and push. Then you need to hold for a few seconds as the thick 5200 is slow to move. Then I would put duck tape over the hole I filled to keep the 5200 from coming out. Then as a last thing I put some metal bars and such directly over the holes so the weight pushed the on the holes and forced the 5200 to spread out. The big draw back is the 5200 takes forever to cure. For me in NJ it is now a bit colder and the humidity is lower. The 5200 needs moisture to cure and likes to be a bit warmer then what the outside temp (well unheated un attached garage) is currently. I am planning on doing more 5200. I am thinking I might first put in a very small amount of water and then blow it in with compressed air. This should help the cure. So that is my current story. I am currently waiting for a more full cure on the 5200 to move on. Also I found HomeDepot is advertising the 5200 at $17.90 or so.