Years ago I did some metal repairs to both steel and aluminum with I think it was "Belzona Molecular Steel".
It was an epoxy kit, two cans of liquid and some cloth mesh. It worked well for repairing a car gas tank that was split on the seam in one case and for sealing a crack in an aluminum cabinet in the other case.
I can't remember where we bought it, might have been Acklands or something similar. Can't remember the price either as I wasn't footing the bill.