Model boilers: The trend seems to be to go with stainless materials...which is fine. We just need to understand that what we are trying to prevent in corrosion, as a result of using stainless, we generally make up in repairs due to cracks. I believe that a well treated boiler (chemicals and the way the boiler is handled) is just as well off with a steel boiler as you would be with stainless. I have seen more steel boilers last longer than stainless steel boilers before a failure begins to happen. Even in a well treated stainless boiler...you will never prevent the inevitable crack in the material.