Repainting Rusty Yanmar

[lockie]

Hi all;

The 2GM in my boat looked a treat when I bought it 5 years ago, but the paint is gradually being replaced by rust in places.

Can anyone advise the best way to treat this and keep it looking if not pristine, at least decent?

The engine is in great shape internally, starts and runs perfectly, and has done a mere 1500 hours so it's got plenty of life left. But it's a bit depressing to whatch it turn into an ugly duckling, not to mention resale when I eventually turn this boat over.

Cheers, lockie

[spraygun]

Can you take it out easily?

Sent from my SAMSUNG-SGH-I747 using Cruisers Sailing Forum mobile app

[delmarrey]

Wire brush the spots and spay it down with break cleaner. Then brush on a good primer for steel, and you can paint over that.

The problem with blistering paint is it holds moisture and creeps outward ruining the rest. You have to stop it at its source. Sea water is getting on your motor and it needs to stop. Yanmars do a lousey job of painting and even w/o an undercoat.

[Andrew Troup]

Might pay to use a rust conversion treatment, such as "CRC rust convertor", for immediate relief.

You can use a small brush (even a child's watercolour paintbrush)
to apply this onto just the rusty patches, after removing oil, grease and loose rust.

It will prevent rust spreading or deepening until you can remove the engine and repaint it properly.

[sailorchic34]

I used plain phosphoric acid available at many hardware stores in the paint department. Phosphoric acid is I think what is in CRC. The acid will pasivate the rusty iron or steel. Plus it acts like a primer too. Brush it on let it dry and paint over it. Worked for me during my engine overall.

[maxingout]

I have 20 year old Yanmars that look new because I spray them with Boeshield a couple of times a years. Magic stuff. Keeps a coating on the engine that keeps the rust away.