It isn't the CO that is rusting the metal. It is the fact that the metal is cold and the heater warms the room. Just like a cold glass, the metal condenses water out of the air. This water helps it to rust.

If the room were keep warm all of the time the metals would not rust.

There is a little more to it than just warming the air. If you were simply warming the air, the dew point would remain the same and no increase in condensation would occur. Unfortunately, water is one of the byproducts of hydrocarbon combustion, so using an exhaust stream for heat will add moisture to the space, lowering the dew point. Your breath will add a little to this effect as well.

 

While this type of heater burns with excess air and should result in complete combustion, there are always a few radicals that get through. In addition, there are impurities in the fuel, such as Sulphur, which form acids and other nasty compounds when burned. These corrosive compounds feed directly into the work space and attack what ever they come in contact with.

 

I have no idea whether this would have a significant impact on eGlass construction.

 

Rob