Engine Room Corrosion

[jlightonjr]

Recently I spoke with a boat owner who has a sedan style boat with cockpit engine room entry. The boat owner equipped his engine room with a dehumidifier that he runs non stop when the boat sits at the dock.

The boat is stored in FL and is a 2003. He felt that the dehumidifier helped to reduce some corrosion and with 500 hours on his diesels I looked in the engine room and for a salt water boat I was VERY impressed at the LACK of pitting on the metals and the lack of green that was on the bronze.

So here is a question, for boaters in salt water what are some tips to keep the engine room in great shape, reduce corrosion and keep pitting to a minimum?

What do you all use? Do you think a dehumidifier is a good idea? What about sprays on metal, fittings, etc.?

Warm Regards,
Jack

 

[Boss Lady]

The largest cause of corrosion is the salt mist that winds up in the engine room and coats everything. Salt is hydroscopic so it naturally attracts moisture, plus the temperature differences of large metal objects (like engines) causes condensation. Now you have a solvent and a corrosive on everything. If you wash down the engine room periodically you can eliminate the salt. The de-humidifiers are a good idea.

 

[luckydave215]

I battle engine room corrosion by coating everything in there with grease........elbow grease.
I apply the elbow grease with rags and 409, Windex, WD-40, silicone spray, and car wax. Lots of car wax.
In the end, you just have to strip and repaint things on a regular basis. It's like keeping up with brightwork on deck.
Get used to it. An engine room radio helps........

 

[MikeP]

Yeah, I think Dave's pretty much got the answer - to keep it clean you have to keep it clean! I haven't found a substitute for that elbow grease. I pretty much do the same thing he mentioned. As far as keeping the secocks/whatever free of the green stuff I found that a coating of CorrosionX works pretty well and also makes it easier to get the green off once it forms.

But no matter what you do, you still have to clean it fairly frequently. There is no magic stuff except in the minds of cleaning-agent marketing people!

 

[34Hatt]

I can't see how a dehumidifier would help. I know when I am in mine I feel the breeze coming thru the vents all the time. How could it catch up it almost like keeping the door open with the ac on

 

[the kuz]

Keeping engine pad heaters on thermostat @ 58 degrees especially from mid fall until late spring keeps engines warm and seems to reduce moisture/condensation on engines/trans. Also I plug vents over winter (except when out boating on nice days ). Also, closely watch quality of paint work in ER. Other than that, the above post on cleaning are pretty much all I know to do. Regards, Bob K

 

[REBrueckner]

For boats in humid conditions like Florida, running air conditioning or equivalently running a de humidifier can't hurt. But I doubt it helps much in such conditions to alleviate corrosion. On windy days a lot of air can blow in thru engine room air intakes. Keeping such dust out could be a benefit.

As noted, when temperatures drop, heat or dehumidifiers can help avoid general dampness. In winter in NY I usually run a humidifier set at about 55 or 60% humidity and it runs more than you would think. I seal all external air entry for the winter as I keep heat on all winter. But my electricity bill goes up ....might cost as much as $25/mo extra with electricity at 30 cents per KWHR. It helps keeps down that "Hatteras smell".

The only other option not posted so far: some new boats use air conditioner/ hot air heat type filters in engine air vent intakes...a loose mesh of some synthetic material. I used some, from Home Cheapo, very inexpensive,for about three years...after seeing them in a new Sea Ray. I cruise at only about 10 to 12 knots so maybe I don't generate much mist that far forward on the hull (there is plenty on a windy day further aft in the cockpit). I figured they might trap some salt moisture...and dirt....but after 400 or so hours of running they are still very clean...For my boat they did not seem to accomplish anything.

Rob Brueckner
Hatteras YF

 

[Brian Degulis]

I used a de humidifier on my last boat and sure on windy days it's proubably not doing much. But you run it 24/7 and it's not always windy so overall it worked very well. I'm in FL so the aditional heat created by the de humidifier was a pain if you forget to turn it off before working in there but it definetly without a doubt substantialy reduced corosion and rust on everything.

Brian

 

[jim rosenthal]

I don't think the dehumidifier hurts anything but I think it is an expensive way to accomplish what you want, which is to keep things from corroding. I use Dave's method- spray everything with corrosion blocker. (This months PBR has a test of these, and there seems to be a new winner- a CRC product that is also sold by WM as a house brand.) I also keep the oil pan heaters on most of the time, which keeps condensation from occurring as much inside the engines.

Since water vapor, like anything else, will run down its concentration gradient, you can't really keep a ventilated engine room very dry. The dehumidifier may help a bit, but the fact that it exhausts warm air may be helping as much as anything...I would think it costs less to run two pan heaters than the dehumidifier.

 

[rswirtz]

Where did you run the water hose for the drain?

 

[Brian Degulis]

Into the bilge

Brian

 

[luckydave215]

I toured another 60C in my marina a couple of weeks ago, and the owner had installed "hepa" furnace filters in the engine room air intakes.
I think they would trap airborne salt spray, and I'm going to try some.
On the 60C's, the engine room air is taken up from under the cockpit coamings and runs forward through the aft engine room bulkhead through ~24" square openings, where I have blaster squirrel cage fans, so some surgery will be needed, but it may be worth the trouble to reconfigure the fan installation.