Ignoramus26696 wrote:
Thanks to all. I cleaned up the pieces, applied a rustoleum primer,
and applied one coat of rustoleum metallic hammered looking paint. I
will apply another coat soon.

This setup will be suspended in the air 99.999% of time, and will be
dunked into freshwater a few times a year at best (quite possibly very
little next year). Given that it is made of 3/8" of steel, it is
unlikely to be damaged structurally by rust before I replace this boat
or I die.

This started me thinking. You're most likely right, but as I said to Tom
Q. earlier, engineering offers plenty of surprises. You get some pretty
weird-ass corrosion sometimes. I looked at a few websites on pitting
corrosion and found figures quoted for mild steel corrosion in harsh
atmospheres of several mm/year. Unfortunately I couldn't find a figure
for pitting corrosion in a pretty regular outdoor, damp, non-salty
atmosphere. Having watched stuff corrode myself, I reckon leaving
something outside with a bit of missing paint might corrode at 0.2
mm/year if pitting started. At that rate you'd have 48 years if you were
unlucky, so I reckon you're safe. But I saw an engine which had been
left outside with the cylinder head removed for maybe 10 or 15 years at
a boatyard on the coast. There was a hole corroded through a piston
maybe 10 mm thick. It makes you think.

You can tell I'm bored tonight...

Chris