Hi all, I'm looking for help. I'm making a mold for the seatback of my Tesla Model S. I've sanded the surface with a 1500 grit. It's silky smooth. I put modeling clay into the crack surrounding the seatback. I'm now looking to create the flanges for the vacuum tape. This design is a little tricky for me. I tried corregated signboard but with no flat surface on the underside. I'm having trouble getting it to stick. I'm now thinking of using pour foam to get my flanges. I'd wrap the piece in a bag, find a big box to where the foam will ooze out the sides of the piece and create the flange. Suggestions?

It's also easier to cut the flange into multiple pieces rather than trying to stick it on as one big piece. Coreflute and the likes are relatively flexible, but the tension it creates on the hot melt glue often causes it to pop off. So it's easier to cut it into 2 pieces rather than bend it.