My Hoopla 4 did not come with any seam sealing instructions but my Hoopster did! See attached diagram — looks a lot like a Hoopla 4! So I inspected the Hoopla 4 and found that the seam next to the glossy side of the shelf was not factory taped. All other seams were. Look closely at the seams, if there is a transparent strip about 1/2" wide covering it, it is taped, if not it isn't. I know from making home-made dry bags that some fabric coatings can't be taped so that could be the issue.
So I put the hoop in and instead of flipping the tent over, I staked it out upside-down and pitched it like that with the offending seam on the outside, easily accessible. I brushed seam sealer into the seam,removing the stakes one at a time as I worked around the tent to get closer to the job. Then I made two dumb mistakes. In my eagerness to be done I took it down 12 hours later, and without talc. The seam started sticking to itself when the fabric folded over onto itself. I immediately re-pitched the tent, upside down as before, pulled the sticking bits apart, waited another 24 hours for it to get good and dry, then applied talc.Now I'm good to go.
Incidentally the instructions say "make sure the pole is not in place when applying the sealer", but I ignored that, did it my way :)



