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Clean Your Room!

It’s hot, cramped, and hard to reach, but your engine room still needs a good scrub now and then. Here’s how the pros do it.

If you’re like me, you’re a little too old and creaky to maneuver easily around a cramped engine compartment. But inspecting your machinery regularly, and keeping it spic and span, is a vital part of maintenance: You won’t see telltale leaks and drips if your engine is dirty. Your mechanic will be happier working in a clean space, so maybe his bill will be lower. And a clean ER is sweeter-smelling—whiffs of dead dinosaurs will no longer waft through your cabin.

Arriving with the right tools and elbow grease, professional cleaners may be a smart investment.

Arriving with the right tools and elbow grease, professional cleaners may be a smart investment. 

Unfortunately, giving our engine rooms the attention they deserve often requires bending one’s spine into a pretzel to reach the area that’s outboard of the motors, not always easy for folks cruising through middle age. So rather than pop a disc or dislocate a hip, or have to summon the fire department to haul me out from behind the genset, I find somebody thin and flexible to handle this chore for me. You might want to do the same—it’s cheaper to pay a cleaning person than an orthopedic surgeon.

For me, that means calling my friend and go-to source for answers to any boat-cleaning questions, Margarita Xistris, owner of Nautical Details ( Anyone who can make a living for more than 30 years maintaining boats in New England, an area with barely a six-month boating season, must be doing something right. When I asked her for tips on cleaning machinery, Margarita summoned me to a Bertram 33 Sport Fisherman she was scoping out for just such a project.

Clean It? I Can Barely See It!

The Bertram was in excellent cosmetic condition even after almost three decades of service, but the machinery and engine spaces needed TLC. Twin MerCruiser engines lived partly under engine boxes protruding into the cockpit, and partly under the saloon. Their tops were easy to reach, but full access meant dropping down through a centerline hatch and then slithering around below. This would be a job for svelte Anna and lanky Nick, Margarita’s cleaning team for this particular project. (Anna was in charge, so I assumed Nick would do most of the slithering.)

Black MerCruisers don’t show dirt like white, gray, or even green engines, a good thing in one way, but bad in another. Black sucks up light like a … well, they don’t call them “white holes,” do they? Leaks, rust, water drips, and other nasties hide in the shadows of a black engine, so regular, detailed cleaning is even more important than they might otherwise be.

An eraser can help you remove stubborn stains.

An eraser can help you remove stubborn stains. 

There’d once been another engine aft on this particular boat, a generator under a leak-prone lazarette hatch. Thanks to excessive saltwater intrusion, many Bertram 33 gensets died an early death. Where the genset once lived, I found lots of dried bilge gurry that needed cleaning. Nick estimated at least an hour’s work to scrub it, until Anna reminded him he’d not only have to clean the bilge, but also sop up any wash water—Nautical Details folks are very “green”—so that hour of cleaning would stretch out a bit. The outer sections of the bilge, from the rudderposts to the chines, were out of reach for even Nick’s long arms, and would have to stay dirty for a while.

Ready for her Close-Up

For Margarita, step one in machinery maintenance is to shoot a few pictures to show the state of the motor or motors before cleaning, especially areas where there might be a problem: Maybe there’s rust on an exhaust elbow, or hoses that look tired, or salt stains that could indicate cooling leaks. Sending the photos to the owner lets him decide if he needs to call his mechanic. More photos taken after cleaning show, first, that the job was done, and also provide a baseline for checking the engine later in the season.

When you think of it, this sort of thing could also qualify as a bona fide use for one of those annoying selfie-sticks. Rather than climb into the engine compartment, you could stick your camera phone down there and shoot away. If you want to try, the Flexion Quick-Snap Pro is $22 on Amazon and seems to get good reviews.

Degrease It

Cleaning an engine isn’t rocket science—it’s more about taking care and spending time over the target, but the job’s easier if you use the right cleaners and careful practices. First step is degreasing, taking care not to rinse gunk into the bilge. Margarita’s crews use Mean Green Super Strength Cleaner & Degreaser (, a biodegradable product that can be used on engine-room bulkheads and other surfaces, too. Spray it on, use a kitchen-pot-scrubber-type brush, toothbrush, tongue depressor, chopstick, or even a Q-tip to break up caked-on grease, then wipe it off with a sponge or rag and rinse the cleaned surface with water. For cleaning flat surfaces, engine beds, especially dingy bulkheads, the bilge under the missing generator, etc., the Nautical Details go-to tool is an eraser (, which works with plain water or boat soap to gently abrade and do away with dirt.

Save on elbow grease by using quality boat cleaners.

Save on elbow grease by using quality boat cleaners.

Use water hoses carefully in the engine room, by the way. Even though most vital engine electronics are in waterproof boxes—these are boat engines, after all, and boats get wet—don’t just spray wildly and spatter emulsified grease and oil all over. You’ll just have to clean it off again. Remember: water in equals water out, and if the water out contains oil or fuel drippings or other non-biodegradable contaminants, you should suck it up with a Shop-Vac and dispose of it properly, not discharge it overboard with the bilge pump. Bottom line? The less water you use during this kind of cleanup, the better. 

Steam It

Some things can be cleaned with plain boat soap and water, but if you’re cutting grease, hot water works better. Which brings us to steam, specifically Nautical Details’s VaporJet steam cleaner ( They say to the man with only a hammer, everything looks like a nail; I say to the woman with a VaporJet, everything looks like it needs steaming. And she’d be right: Steam, in this case superheated steam at almost 300 degrees, not only loosens dirt, but kills bacteria and viruses, removes allergens and eliminates odors. If your upholstery smells like a wet sheep, steam will make it sweet again.

Margarita Xistris

Margarita Xistris

And in the engine room, steam can break up grime and soften grease, using a minimal amount of water and no chemical cleaners. Bilge areas, grimy hullsides, under the engines and gearboxes, even super-caked-on grease on the engines themselves are all candidates for the VaporJet. Areas beyond arm’s length (like the ones between the Bertram’s rudder posts and chines) can be cleaned with the Vapor Jet’s long extension nozzle and plethora of attachments, but Margarita said the process works best when you can wipe off the surface after steaming. It’ll make the engine compartment smell nicer, too. You probably don’t want to buy your own VaporJet, so hiring a pro with one can be a good investment.

When a job is finished, Margarita leaves an absorbent pad under each engine so any fluid drips will show up clearly. It’s best to have a drip pan or pans here, but most boats do not—maybe that’s an investment to consider, too. Even if you have a pan, however, the pad corrals the drips and makes them easier to clean up. 

Once you’ve spent time and/or money spiffing up your machinery spaces once, add it to your maintenance list; regular cleanings are more touch-ups than scrub fests, and if you’re lucky you can get through the season without calling your chiropractor.

2018 Boatyard rule

Touch Up the Paint

If you’re serious about keeping your engines looking sharp always have a can of touch-up paint onboard. Nothing shouts shoddy maintenance louder than a rust-patched, paint-flaking motor, and it’s easy to avoid. You don’t have to be Rembrandt, either: Basic prep and a light touch with the spray can are all it takes.

Scrape off flaking paint and knock off loose rust with a brass- or bronze-wire brush, taking pains to control the metal bits and dust. Feather the paint edges with sandpaper or emery cloth, and wipe off any remaining dust with a rag moistened with rubbing alcohol. Prime the metal with Ospho or another rust converter to form a solid, rust-resistant base for the new paint.

Engine manufacturers sell touch-up kits in the appropriate colors, and Dupli-Color and PlastiKote both make paints to match common engines. Your local auto-parts store may carry them. (Use engine paint that can withstand high temperatures.) If the paint manufacturer recommends a primer, and you’re feeling ambitious, order it, too. I’d be OK with painting right over the Ospho, however.

Mask the area you’re painting using whatever creative method comes to mind. Masking tape is a pain on engines, so I usually just drape old rags where I don’t want overspray. If there’s no way to mask small areas, smearing them with Vaseline will keep paint from sticking. Let the paint dry and wipe it off. Spray the touch-up paint on in multiple thin coats, letting each coat tack-dry for a minute or so. Too little paint is better than too much. When you’re done, invert the spray can and blow out the nozzle, then stow it for next time.

This article originally appeared in the August 2015 issue of Power & Motoryacht magazine.