Corrosion Protection

[rayjay]

I need some help from all you guys who boat in salt water.

Started to collect bits and pieces for my engine, and was wondering what is the best way to protect things like AL oil pans, centrifugal superchargers, chillers / intercoolers, throttle bodies, and AL intake manifolds. I’ll be running in the salt water of Long Island Sound and will be installing a closed cooling system. The boat will be trailered or fork lifted so it will not be sitting in the water. But as I live within walking distance of the Sound, there will always be a bit of salt in the air. I’ll have to be doing this to the AL pieces of my car engines too just as a precaution. Will ceramic or powder coating work? Should it be applied inside and out?

Below is a picture of the intake system I am considering buying, and there are a lot of bright shiny polished AL pieces there I would like to know how to protect.

Thanks,

rayjay

[Morgan's Cloud]

I know your predicament very well...

Closed cooling a big plus but your engine has many parts I've never had to deal with.Exotic finishes and powder coating unavailable here.
I've always relied on a good moisture displacing spray to keep corrosion down.
Boeshield is what I've been using for a while now. Is cleaner than the others I've used and does'nt 'melt' off the warm engine as easily as some do.. a bit overpriced if you ask me though.Of course there's new products introduced almost monthly now so someone else around here may have something else better ...

S

[Forrest]

There is no real way to protect bare aluminum parts from corrosion due to contact with salt water. The only solution is to provide protection through a protective coating such as paint. Since aluminum forms a very thin oxide on its surface almost immediately after machining or polishing, it very difficult for almost any hard coating to adhere to the an aluminum without proper preparation. In order for a paint coating to adhere, it is imperative to use the correct primer that literally etches the surface of the aluminum. The primer of choice in the marine environment is zinc-chromate primer which is usually green or yellow in color. Other aluminum etching primers exist that may work well in an un-submerged application, but unfortunately I know of no "clear" aluminum primer that could be used with a clear paint in order to show the beauty of the polished aluminum parts. My only suggestion if you must have the polished aluminum look is to keep the parts wiped down with a protective petroleum product LPS, CRC, etc., or one of the hi-tech expensive versions like Corrosion Block. A chrome-look powder coating may also be an alternative.

[MOP]

I have been a salt wrench for a long time, you don not have many options. Zinchromate is very good on aluminum, Pettit Rust Loc is the best on iron and for super grip on galvanized stuff. The pretty stuff all you can do is spray regularly with any good corrosion spray. I wash my motor down every so often and re spray so it don't look to gooey.

MOP

[RickSE]

I'd suggest anodizing for AL parts. You can get anodizing in almost any color. Hard coat anodizing (Mil-A-8625, Type III) typically has 50% buildup & 50% penetration and you can specify the thickness. There also is an anodize called "Anodize with Duralox Seal" which states, "The ultimate seal for salt spray resistance on all alloys. 8000 hours+ without pitting on 6061 and 2024 aluminum alloys". This is from our anodize vendor,

Barry Avenue Plating (http://www.barryavenueplating.com/index_ie.php3)
Los Angeles CA
310-478-0078

Powdercoating is nice but it still can chip and peel allowing corrosion under the surface. Anodizing can be scratched, although hard anodize is incredibly though, but it will never chip or peel.