: You shouldn't use ANYTHING with silicone in it to attach bulkheads, as
: silicone products bond weakly and leave a residue that makes it difficult
: to get anything else to bond to the same surface after the silicone
: inevitably fails.

I honestly have no idea why silicone caulk is so popular for everything. The stuff fails after a couple of years, regardless of the application, and when you go to repair it, new silicone caulk will not bond to old silicone caulk. It's virtually impossible to remove completely, and you have to remove it completely to apply anything new over it. There are plenty of other high quality caulks out there that can be repaired much more easily when they do fail. And when it comes to bulkheads, caulk will never be as strong as epoxy.

I used to like silicone caulk because everybody always said it was the high quality caulk, but after using it for a decade or two, I'll never buy another tube of the stuff.