I am adding my Lowrance Structure Scan Transducer to the rear of my skiff. The transducer is already bolted to a 6061 T6 aluminum plate the is form fitted perfectly to my hull. Now all I have to do is tape, glue or bond the aluminum plate to my high density polyethylene hulls, without bolts, screws, or modifying the hulls in any way. I wanna stick it and forget it.
Anyone have any experience attaching dissimilar materials to hdpe, so my transducer does not pop off every time a gator wraps a line around it?
Quickest answer is that pretty much nothing sticks to HDPE. That's what high density polyethylene it was designed for, and why it is used for buckets/barrels/etc. Mechanical fasteners are the very best solution, especially if you expect a gator to wrap a line around it.
There are some epoxies that claim to work. West Systems has a product called G-Flex (instructions here), but the couple of times I tried it on hdpe kayaks it only sorta worked.