I orginally bought this product to seal the seams in a project for Camping.  I recently woke about 4:30AM in my water bed, wet and cold.  I needed a patch kit and thought of this.  Worked like a charm.  I cut a little patch from the instruction flap and smeared this stuff on one side and after drying the area put it on.  After about 20 minutes I went back and put a layer all over the patch and extended it out over the edge onto the solid portion of the mattress for about 1/4 inch and left it for the recommended 8-12 hours and everything is dry again.  I had some other stuff before and it was junk.  Im here looking to buy some more, just in case.