If you really don't want to permanently attach a shelf to your melting pot then you can do what I did. I built a base for my pot to give it some stability, as they get rather top heavy when full.
Yesterday I had some time to finish up my shelf project. I bought an 8" x 24" piece of flat steel from Lowes, bent it around a 2" x 10" to create the corners, screwed it into my base on the sides and cut off the excess with an angle grinder.
It's not perfect but it gets the job done and allows me to pull my melter out and store separately.