Removal of Glue/Cement on outside of tanks?

[Colonel Sanders]

So I have a couple of jacketed brite tanks that were once used for the bottling line and are now in our cold room. They were originally wrapped in neoprene to help insulate them during bottling, but have since had the neoprene insulation removed. Unfortunately, there is a hardened glue/cement that is seriously bonded to the stainless, nearly impossible to remove, hideous, and always raises questions during tours. The only way I have had success removing the glue is by manually scraping it off, which tends to scratch the hell out of the tanks. Ive tried caustic, acid, sovlents, heat, and elbow grease. Im just hoping that someone else has encountered this before and can give some advice/hints into this situation.

Thanks,

The Colonel.