Help with corrosion removal

[ccm71115]

Hello,
I have a 2006 Yamaha F150 that has developed some corrosion on the lower unit. I discovered it when I removed the prop to lubricate the splines. It is kind of hard for me to describe where the corrosion is but it is inside of the space where the thrust washer sits. Due to its location it will be really hard to remove via sanding or with a file. My questions are:

What would you recommend to use to remove the corrosion?

Should I prime and paint over the areas after I remove the corrosion?

I have some Yamaha paint that I could use to repaint the cleaned
surfaces. Do I need to use a special primer?

Thanks in advance for your suggestions.

Charlie

[robert graham]

Apply a mild acid solution with a spray bottle and scrub area with a brush. Acid should be strong enough to foam a bit when you spray it on. Rinse with fresh water quickly as soon as corrosion is removed. Repeat acid, brush and rinse until clean metal is showing, dry it thoroughly(maybe with a heat gun or a hair dryer), prime it and paint it. Good Luck!

[99yam40]

I think I read some where that vinegar was good for removing or loosening aluminum corrosion

[robert graham]

Once you remove that white aluminum oxide corrosion completely you may consider spraying that entire area with white lithium grease, rather than the primer and paint. The white grease sets up semi-hard and can remain for quite a while providing excellent protection from water and corrosion, and it would be much easier than trying to prime and paint that area behind the prop. I use the white grease on my tilt and trim unit motor, pump, rams,etc., and it works very well. Good Luck!