It's called "Pliobond" and it's a contact cement, as is shown in the above post, the Pliobond was used on the seals for the storage compartments which were coming loose at the corners (look at the photo of where my hand is on the storage compartment). I think some of the slide seals (The large ones that are glued either to the slide itself or the frame) have contact cement on them, some seals for the slide have a channel that the seal fits in to hold it in place, you just have to look and see how the seal is installed on your trailer. When the slide is out, the large seals flip out and there should be an overlap at the top corners between the vertical seal and the top horizontal seal so that the rain water flows from the top corners to the outside of the vertical seal, of course the trailer must at least be level or at 1/2 bubble off level so that the slide is tilted downward a bit to get the railn water to run toward the outside end of the slide. If you have two slides, one on each side of the trailer, of course you can't do this and in this case I would consider getting an awning for each slide-out, in fact I have only one slide-out and I'm considering getting an awning for it. You can find replacement slide-out seals here:
http://www.rvsurplussalvage.com/cata...ategory_id=106