304 vs 316 form rudder stock

[northwind]

I'm looking at replacing my aluminium rudder stock with stainless steel.

I'm wondering about using 304 stainless, and protecting it with a powder coat finish.

My question is, how suitable is 304 in the marine environment? I understand that 316 is the ideal, but the price difference for a 6mm square metre of the stuff is quite large.

 

[Neil_Y]

Not suitable is the simple answer, 316 is, as far as we are concerned the bare minimum for marine use.

Stainless is quite vulnerable if there is any chance of oxygen depletion so make sure all areas are either well protected (epoxy) or have free flowing sea water, not trapped areas with little movement.