Corrosion prevention in bilge under engine?

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SuzieWong

Member
Joined
Jun 24, 2018
Messages
12
Location
Hong Kong
Dear community members,
Currently I have a situation which will develop into a problem in the long run if not addressed.
I had a diesel leak in the engine room. After treatment with bilge cleaner and cleanup I discovered that the paint in the bilge underneath the engine is not diesel resistant: the paint started bubbling and paint comes off in flakes.
As this is a steel hull I am very concerned that rust will develop there.
Unfortunately the area is not accessible for sanding and applying paint by roller and brush.
Has anyone experience of how to do rust protection in an area which is very difficult to reach?
 

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Greetings,
Mr./Ms. SW. Welcome aboard. We visited Hong Kong back in 1996. Interesting part of the world.
 
Hard to tell exactly the best approach without knowing the amount of space you have to work with. My thoughts go to a pressure washer with long wand to clean as much of the old paint / grime out of the bilge pocket as you can. Then a similar long wand spray paint wand to spray a product such as POR-15 to coat the bare metal.
If you use POR-15 be sure to wear a respirator and ventilate well - it is great stuff but highly toxic.


I'm personally glad that my boat was fitted with Detroit Diesels and therefore keeps the bilge well oiled to avoid corrosion :D
 
In our last boat I went ahead and pulled both engines, one at a time, in order to cleanup and paint the bilge. It was a big job but certainly doable. I built a crane in the salon and lifted each engine up and then slid it over and stacked it above the other engine for the winter. Then I had a lot of room to work. It took 3 of us about 2 hours to pull the engine and stack it.
 
Much of what you show in the pictures is accessible by a small size worker
armed with soap and water and rags on sticks. Sand areas you can reach
and follow that with OsPho which is just diluted phosphoric acid.
Epoxy bilge paint would be a good choice.
Small brushes on sticks will reach most spaces you can see. Tedious, yes.
I am not a big fan of POR-15 but that would probably be OK to use in the
bilge. The name implies that you can paint it on over rust but don't!
 
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I like POR15. I have used it on the metal motor mounts in several boats. I followed the directions explicitly and never had any more rust show up. They have an excellent degreaser.
 
Difficult or not, you need to clean, prep and paint if you're going to avoid rust. There are products that will eliminate rust by soaking or brushing like Evapo-rust without sanding, down to good metal.
 
Eastwood makes some good products for rust that comes in spray cans. I use this in areas I can't reach and I'm more concerned about killing the rust vs overspray.
 

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