Advice re diesel engine with rusty oil pan

[Althebass]

Our Nicholson 32 sailing yacht is powered by a very reliable Perkins Perama m20 (3-cylinder, 18hp) which dates back to 1998, I believe. The only problem is that the oil pan is showing signs of rust. No oil is leaking (yet!) but I am trying to prevent a catastrophic failure while at sea.
Access isn't great (I suppose there is six inches of space below and access is from the front of the engine bay), so replacing the oil pan would most probably require engine removal from the boat.
My question: can anyone suggest a remedy for repairing or reinforcing the oil pan without removing the engine? Additionally I have heard from another owner that the bolts securing the oil pan are difficult to remove and are prone to break.
Any advice would be much appreciated!

[2big2small]

I once had an oil leak on a Yanmar 3GM. I just put a metal brush on my drill and went under the engine to sand the affected area. Then I applyied an epoxy based two-component “cold welding” paste. And finally I spraypainted the area with a black paint in a can meant for cast iron fireplaces. You then have to run the engine for its heat to cure this paint. So it didn’t cost me more than $30 and a few hours and I never removed the engine. It worked fine for years afterwards with more tha a 1000 extra hours on it before I sold it.

Sounds to me that with 6” of space you should be able to brush the rust away and repaint.

[a64pilot]

I’d knock off as much rust as possible and then apply one of the rust killers, which I believe is Osphoric acid, I think it converts rust from iron oxide to iron phosphate. Whatever it does, it stops rust chemically and seems to keep it from reappearing.
I’d brush paint myself as I’d make a mess trying to spray.
I would not put a layer of anything except maybe rustoleum on the pan as I’m afraid you may just encapsulate the rust and make it worse. With paint you can regularly inspect and see if the rust comes back

[senormechanico]

I have a Volvo MD2020 which I think is the same engine.
I had the same problem years ago, but with only about 3 inches under the engine.
As our engine is accessable from above, I pulled it using the main halyard and another 4 part purchase on the aft end of the boom.
I just left it hanging there and removed the pan (no problem at all) and wire brushed off all the paint, soldered a few small rust holes and repainted it with Rustoleum spray paint.
That was at least a dozen years ago with no reoccurance of the leaks.

[robbievardon]

A64 Pilot, little query on your rust treatment. If you encapsulate the rust, do you not deprive it of the oxygen it requires to grow? The inside is protected by the oil swirling around.Mind your eyes if you use rotary or handheld brush as both can eject loose wires at any time.

[Althebass]

Thanks everyone! I'm feeling much more positive about fixing it

[AlanR]

a64pilot says: "I’d brush paint myself as I’d make a mess trying to spray."

That should stop him from rusting.

It is always worth reading your message before you post it. My primary school teacher told me that.

[Suijin]

Originally Posted by Althebass

Thanks everyone! I'm feeling much more positive about fixing it

Fix it now. Sure beats sitting there for hours in a seaway with a roasting pan and a turkey baster, recycling leaking oil. Ask me how I know.

[Althebass]

Thanks everyone. My engine is now degreased, wire-brushed, rust removed with phophoric acid gel then primed and painted in Perkins blue