It's interesting you should ask that. I had some issues getting the EternaBond to go over the spongy material without getting a bunch of air bubbles. The tape sticks to anything except silicone so sticking to the old sealant was no problem. The 4" wide tape was enough to cover the old sealant well but then I discovered that I could just peel that old material up so that's what I did on half of the area around the skylight and that eliminated the air bubbles. The tape is not supposed to be stretched. I know that because Jayco stretched a piece of it that covers the outside seam on my main slide out and it started to lift in a couple areas. I had the dealer repair that under warranty soon after I purchased the RV. I also used the EternaClean product to clean all surfaces then applied the EternaPrime before applying the tape. Probably a whole lot more than you wanted to know

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