Old hws

[aitken1929]

Hi guys I'm from Australia and hoping that this hot water service is designed the same way world wide it is a old Bristol heater with a internal copper tank and a sheetmetal outside with this corky insulator in between the two with a cast iron base and legs, now my question is what is that corky insulator?

 

[Beni]

Hum. probably cork. It is used as in insulation in some parts of the world. Most water heaters in the USA have had fiberglass insulation for the last 70+ years or so.