[FlyboyTR]

After doing my initial repair as noted in this thread, over time and miles things shifted and my soft spot returned. Wavery's suggestion about using the expanding foam was a good suggestion. Except....

I had concerns about being able to remove the tub (if the need ever arose) because the expanding foam would have to be cut before the tub could be pulled. This was my solution...

I add a length of vinyl hose to the spray foam spout. I went in through the bottom/floor vent. I then inserted the hose into a lightweight garbage bag and then worked the bag into the area where I wanted to foam. Once satisfied with the bag placement, I then started spraying the foam. The bag expanded around the areas I needed. I did sort of pull the hose a bit and added more foam as needed until I was satisfied. After curing, I removed the excess bag.

I didn't remove any of the extra foam that had expanded beyond my intended target. Since the vent was still about 60% clear...I didn't worry about it. In hindsight, I wish I had used a smaller bag. BUT...things are solid and I have no worries about the foam being stuck to everything should service ever be needed.

Travis