“Why is my near-new ram shaft showing signs of rust?”
The hard chrome finish on ram shafts is micro-porous, which means if it is situated in a salty environment the moisture can go down through the pores to the base metal and rust outwards. This is especially noticeable if the new shaft or new ram is left extended, especially in coastal areas.
After the ram is in use for a while the oil and warmth created in operation will tend to seal these holes up, which is the reason that once a ram has been in use for a time it is a lot more resistance to rusting.
Ways to prevent this from happening are to apply wax or soft-seal or equivalent product. Once the ram has been in use for a while it is normally ok.
If the ram is to be exposed continuously to a salty environment, consideration should be given to making the shaft from stainless steel – 2205 or similar, or hard chrome plated stainless steel.