Aluminum Corrosion

[Stormin' Norman]

Does anyone have first hand, personal experience removing and neutralizing corrosion on cast aluminum?

I was given a never used, 3 year old pressure washer, 3k psi, 190cc (6hp) Honda engine. The unit was stored in a garage that was about

200 yards from the pacific ocean.

The owner could not crank the engine and didn't want to be bothered with it. Upon examination I discovered a fair amount of surface corrosion on the flywheel and some of the cooling fins on the crankcase and cylinder housing.

After knocking off the corrosion from the flywheel, removing the spark plug and inspecting the cylinder I am able to easily crank the engine by hand.

I would like to completely remove all the corrosion and neutralize it. I remember the air crews using soft wire wheels, phosphoric acid, detergent and lots of clean water to deal with some aircraft corrosion.

Does anyone have first hand experience dealing with this kind of issue? If so, would you please share your knowledge?

[gfretwell]

Boeshield

[Ed Pawlowski]

The corrosion is actually oxidation. Depending on the severity you can use SOS pads, vinegar, sodium hydroxide. Loctite makes a jelly you put on and wash off. I've not used it but I saw the results a friend used and it was ok.

[Stormin' Norman]

This looks like a very interesting product. $19 for a 12 oz spray can on Amazon. Would you mind sharing your experiences with it?

[Stormin' Norman]

I have subsequently gotten some more information from the original owner. Turns out he had the unit stored under a shelf that had some drain cleaner on it. Apparently the container of drain cleaner ruptured and dripped on the machine which is what caused the damage / corrosion. I suppose you could call it oxidation, but that would be akin to calling stage 4 cancer a minor medical issue.

So, now, I will neutralize the acid with a slurry of baking soda and thoroughly clean the area.

The sodium hydroxide you mention is basically lye, which is a component of a lot of drain cleaners, so, I will avoid that. The Aluminum Jelly, by loctite, is basically phosphoric acid, as I mentioned above.

I think a lot of neutralizing, scrubbing and protecting is the best I will be able to do. Drain cleaner is nasty stuff.

Sounds like a good job and learning experience for one of the grand kids.

[gfretwell]

It did a pretty good job cleaning up the cases on a Harley that was on fire

[Stormin' Norman]

So, you just sprayed it on the aluminum engine components and wiped it off? Or you had to do a bunch of scrubbing? Or, it had to soak for a while? Feel free to elaborate and let me know if there are question I have not asked but should.....

Thanks.

[gfretwell]

It took a little rubbing.

[Stormin' Norman]

Thanks

[gregz]

Navel jelly is a bit stonger, more effective.

Greg

[Art]

In addition to Boeshield mentioned by gfretwell, the following are also used in the aluminum aircraft world:

ACF-5

CorrosionX

[Stormin' Norman]

Thank you very much!

[Stormin' Norman]

Thanks for your input Greg.