Mcallis, I would recommend a clear 100% "Silicone Seal" product -- such as this one at Home Depot
http://www.homedepot.com/p/GE-...
You can get it in the tubes to use in a caulking gun, or in toothpaste-size tubes. This stuff is used inside aquariums, once it cures it is completely clear, waterproof, and nontoxic -- and it's strong enough that when we remodeled our bathroom and had the shower tiled, our "tile guys" used it to attach the ceramic soap dish thing to the tiled wall. It probably says something to this effect on the tubes, but I would try to apply it on a dry, mild, overcast day and give it a good 24 hours to cure.
The Seal All is a "contact adhesive" that no doubt contains some solvents that will dissolve the poly greenhouse panels. And, unless that's a different type of Gorilla Glue than what I've used, I would think it would make quite an unattractive mess around the panels.
I hope that helps -- another thing is, I would think you would want to use the silicone seal the entire length of the panel sides, if that isn't what you've been doing (the reason I mention that is the apparent small size of the products that you show in the photo, it doesn't seem like those amounts would go very far. Which is probably just as well since they didn't work right
)
