Topper leaks at interface with truck bed

[yodabest]

HELP With Preparing 3rd GEN Taco For GFC install

@oddball this is what I used under the bed rail. I got it at Home Depot for like $5 for a roll. It’s super thin and very sticky it’s Also flexible. It’s pretty cold here on the East Coast so what I did was took a torch and very lightly heated the top of bed so that the adhesive would take better. Then after it was applied I took a razor knife and cut just a small enough hole so when I put the cap back on the clips would go through it. Also before I put the cap back on I ran two to three lines o…