Whatever steel your Hang, Handpan, or Pantam is made of, preventing rust is a must!  While it has been common practice to use oils to protect your instruments, my time tuning and oiling hundreds of Saraz handpans as well as instruments from other makers has revealed that sometimes oils can shorten the decay of the sustain.  While the answer is not totally clear as to why some instruments lose an amount of decay from oil use likely occurs from the various nitriding recipes and polishing techniques used by different builders.  This experience and conversations with other builders lead me to try and find an alternative to oil on the instrument while still maintaining a completely natural and organic formula that is free of scent.   After 1 year of research and rust testing, I finally settled on a formula using using two natural waxes mixed with coconut oil that can help preserve the original sound of the steel as well as provide a protective layer that leaves the instrument feeling dry.  Builders and players of stainless steel instruments have often switched to using Pure Sound Wax on their instruments as the oil options often leave stainless steel feeling wet and greasy.  If you find for any reason that the wax shortens your sustain, it is easily removed with rubbing alcohol and a soft scrubbing pad.  In these cases, oil may be the best option for your particular instrument.  In the case that oil is your preferred method I recommend using Phoenix Handpan Oil, which is the only oil made specifically for handpans. I also highly recommend knowing what product the builder of your instrument recommends for rust prevention.