Removing old seam sealer

You could try using mineral spirits (just like some use to thin seam sealer when applying) to re-dissolve it and then wipe it off. Just soak a rag or brush and start scrubbing. I have no idea whether this works or not.

I'm sure someone with actual experience will come along soon….so free bump :)

For urathane, you could try Acetone or toluene. But be carfull about any fabric. Some of the polyester types will also disolve. Cotton and nylon appear to be immune to it as is PET.

I had a buddy here suggest that I just seam seal the inside of the tent. In the meantime, good thing the wife is out of town. I have it setup in the living room in free standing mode (very cool BTW) flaking off the old stuff by hand….

Agree with your buddy, just seam the inside.

You could also apply bonding tape on the outside over the flaking off stuff and that could help a bit.

Urethane seam sealer oon a silnylon fabric? Yeah, that's going to peel!
You could try a few strips of sticky tape: it might stick to the PU and pull it off. Let it bond for a few minutes first.

Cheers