Bill, that stuff is ok, the problem is that when you heat the aluminum, you change the molecular structure of the metal and it becomes softer/ more malleable. This means the repair( when the alloy rod is added) wont split again, but the chances of the edges of the repair will spilt again.

Op, first you need to remove the roller. It needs to be welded to hold for a long time, anything else is wasting money. If you insist on putting jb or marinetex, make sure it covers a wide area. You need a lot of adhesion/ surface area to keep the patch from ripping off.

Mine gets a similar treatment several times every year, I'm to cheap to have it fixed(split is under a rib) and I keep saying that this year is the last year on this boat... I've had it 25 years- she's been a good one.