I found some serving trays the right size. The metal ones that I made, I cut it out, bent the sides then the ends. I had cut the ends where there was a tang that went over the sides. Screwed the tangs and sealed. Have got some of the stuff like the guy that put a storm door in the bottom of a boat, haven't tried it yet though.
I have quit using oil and gone to dish washing liquid and water. Good luck
Joe