Stainless, or not?

[Alcyone]

I'm in the process of fitting a new engine to our yacht. As part of the job, there are quite a few places, shim plates for the engine mountings, bolts, washers and so on, where I could, and would like to use stainless.

Should I be worried about galvanic corrosion, or just get on with the stainless?

 

[pathfinder]

I used stainless steel flat bar to raise the bearers 10mm when I replaced my engine over two years ago.I also made stainless shims and used stainless bolts.No probs so far despite sea water spills etc when cleaning the heat exchanger stack.Mild steel seems to rust when used here no matter how well its coated.

 

[vyv_cox]

Galvanic corrosion could be a problem if your engine sits permanently under water. OTOH if it is inside a dry boat the risk is minimal - non existent. There cannot be corrosion if there is no water present, so wipe a bit of grease over everything to cater for the possible damp atmosphere and don't worry.

 

[Redwing228]

Should I be worried about galvanic corrosion, or just get on with the stainless?

Shouldn't be a problem as these parts are normally dry. I used stainless extensively, for drip-pan, mounting bolts, shims etc., when re-installing an 8hp Stuart two-stroke in a timber launch a few years ago, with no corrosion problems.

 

[Alcyone]

Brilliant. Thanks guys. Stainless it is, then. Missis will be pleased. She's paying!

 

[omega2]

Some expert used stainless bolts on our rocker shaft pedestal, guess what they work hardened and snapped, if there is any vibrations in the vicinity we were told to use mild steel.

 

[Seajet]

Be careful to use Marine Grade 316 Stainless Steel, for both nuts & bolts etc, penny washers + backing plates ( with wooden backing pads in between if possible ).

Even fighter aircraft stainless can have a 'rust' look after a few years around salt water - though not actually corroded.

So go for 316.