Everything you need to replicate an original is at your local Menards or Home Depot.

Start in the paint department and find the "Heavy" plastic. I think it is 4 mil, but don't exactly remember.

Next, go to the tape isle and grab the black duct tape available. Now head over to the plumbing department and find the plumbers putty. This material rolls into a perfect ribbon as the original to seal the plastic.

Hope this helps.

D