Originally Posted by garystrome
Insert a hypo needle full of contact adhesive into the bubble. Press flat until set is complete.
What you're addressing is a delamination of the raft material--the external coating separating from the fabric. This happens after the internal coating has broken down, allowing air to pass through the fabric and form bubbles. I've seen this happen many times on blue Riken rafts, but never on the gray ones, like this Shoshoni.
And in any case, sealing the bubbles down with glue in a syringe is at best a temporary fix, since it can't address the underlying problem.
But as I interpret the problem with the Shoshoni, it is not surface delamination, but rather ballooning of the entire floor structure. This is what commonly happens when the internal I-beams tear or separate from the top and bottom layers of the floor. It universally results from water inside the floor, combined with the fact that Riken never installed pressure relief valves in their floors.
Typically, the failure mode begins with weakened I-beams or I-beam adhesives. Then when the raft is pulled out of the river, the air inside the floor quickly expands, causing the I-beams to separate or tear. The result is that the floor (or part of it) takes on the appearance of a pillow instead of an air mattress. And as I said before, it is not practical to repair this kind of problem.