Advice needed: How to remove exhaust soot on bulkheads

Dear Gcap forum

I have no doubt that some brilliant mind in here has the experience to help me and my engine boys out.
We have suffered from pretty bad exhaust leaks in our engine room and this is proving incredibly hard to remove with just rags, hot water and the vhemical we normally clean with.
There must others who has had this problem before, do you know of a certain chemical or other that removes this without too much physical labour??
Thanks in advance from the Esvagt Innovator :slightly_smiling_face

‘Second Engineer!’
‘Remove that soot from the bulkheads’.

Return to cabin.


This discussion may help or point you in the right direction.


I used Cleanbreak from Unitor sometimes on hard to clean things. Smells kinda like WD-40 and works similar. Then we’d hit it with Enviroclean which is a citrus cleaner to remove the residue and get rid of the slipperiness. Always like Enviroclean for general cleaning.

I worked on a brand new OSV that got about forty diesel driven pieces of client equipment on the back deck for several months, and so we had a lot of soot come indirectly into the engine room. Anyway, we tried most of what was mentioned and still had discoloration and were starting to scrub the paint off so before we drove ourselves too crazy we just painted.

Stop the exhaust leak and then use soap and water for cleaning.

Back before the days when we worried about how much water (& oil) was introduced to the bilge I seen mixtures of washing powder, hot water & diesel cut through soot like a warm knife through butter. It didn’t do anything for the discoloration but easily made pipes & bulkheads soot/oil free.

If you are managing the clean up personally, don’t tell your crew to clean all the bulkheads in the engine room. From my experience, when I told some crew to do that they would either rush through it to get it done not doing a thorough job or complain that it was too big of a job & take forever. Assign each watch or crewmember a small section each day, telling them you want them to focus on cleaning that section the best that it possibly can & move on.

As mentioned above, make sure all the leaks are fixed first & paint it as soon as you can or all that work will be for nothing. Every C/E, Capt, office rep & inspector that comes through later will see the old stains, think it is a recent leak & have the crew washing it all over again trying to shine a turd.

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If at all possible use a power washer, even if you have to make a tent and do one area at a time. you will still have some coloration left over, I also think that ‘‘sticky’’ feeling left by many soaps contributes to the problem. if you want it white you’ll probably have to paint it but a power washing should be good enough for most.

Since 1971 I have inspected plenty ships of all sorts and also bought some of them. In the engine and tanker pump rooms I first looked in the bilges. Dry, clean inner bottoms were a good sign. Then I talked with the crew about any mechanical, electrical and structural problems they were aware of. No need to crawl around in double bottoms, cofferdams and void spaces to get a feel of the ship. And then I studied the log books. Most crew actually registers problems there. I never found any problems of soot removal on bulkheads, though!

Man, what was that cleaner we used to use on tugs in the 80s. . . came in plastic five gallon buckets. Royal Cleaner, or something like that? It was good stuff.

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Rig Wash, Blue Max, Royal Diamond, Purple Power, Red Devil, Superclean & I’m sure several others that I forgot. The worse it was for your skin the better it was for cleaning. For a 2 man engine room I would clean one side, 1 gen & one main & the assistant would scrub the other side before each crew change. I’m damn sure the environmentally safe, non emulsifying stuff today isn’t as good at busting crud like the older stuff. I could feel the natural oils in my skin disappearing just by opening a bucket. That stuff was strong.

Maybe it was Purple Power. Hell getting old. . . .I do remember that we would use the empty buckets, with lid, hooked up to the airbox drains on the EMD mains. It was a good way to keep a flow through the airbox and prevent an airbox fire. I always installed them on my mains and never had a single airbox fire. Just had to remember to dump them every once and awhile. Oh, but I digress. I do recall a more environmentally friendly cleaner that was made from orange oil and was also pretty effective. . . and left the machinery space with a pleasant citrus aroma. . . .

Was that CitriClean or something like that?

Gamlen was my favorite of the eco-destroyer products.

<story time>

I bought a 25L drum of multi-purpose cleaner in the now-gentrified fish market district in Oostende. The guy told me to be careful and always use gloves, even when working with highly diluted product, because a friend of his had neglected to do this, and his nails hadn’t grown back out. Oh baby, now we’re talking!

The stuff worked great, it laughed at shaft grease and anything else you pointed it at, only real issue was that it would strip paint if you let it. We just called it nasty shit and used it for everything. A little bit went a long way, so we kept a bit in an old PET bottle clearly marked “NASTY SHIT!” and put the drum away in the paint store. I figured that was plenty safe, because who would drink from a bottle with that written on it?

Things went well for a long time until we were in Tunisia having work done. One of the yardbirds figured Nasty Shit must be somebody’s name, and was sure Mr. Shit wouldn’t mind if he “borrowed” his water bottle. Thankfully, he noticed that it was foaming a bit much for drinking water, and tested it on his fingers, whereupon all hell broke loose. He was very angry with me. I asked him: “So what does your religion say about theft anyway?” which put an end to the discussion.

In the end, I learned my lesson about using food packaging for harmful substances, and have also come to realize that pictograms have their place.

As for stripping soot, there is literally nothing out there that’ll dissolve it without all kinds of exothermal fun and games. The best you can hope for is to dissolve the carrier substance. I’d use nasty shit if I had it…

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I worked of a GoM OSV company in the early 2000’s where some cleaning supplies were purchased at the grocery store. A crew member on another vessel mistakenly placed a bottle of purple floor cleaner in the walk-in with the juices. Another dope came by & poured a big glass of it without reading the label or smelling of it & took a big gulp. The office people had a fit & had a company wide safety stand-down. Over 100 boat crews had to stop whatever they were doing to discuss some idiot swallowing a mouth full of purple floor cleaner!? My question/comment at the end of the meeting was, “Why don’t the office have a safety stand-down & discuss not hiring so many morons?” Even if I stupidly drank a mouth full of floor cleaner I sure the hell wouldn’t tell anyone & deny it if someone seen me.



Whatever you wash with, if it ends up in the bilge you will have to process it unless you are able to hold it for pumping to a truck. Read the label carefully or you will wreck your OWS and spend a lot of your precious time getting it functioning again. Most detergents will create an emulsion and you will be screwed.
I would try to minimize how much waste water generated, period. Maybe work one small section at a time.
One more thought- soot is a carcinogen, good ppe is an absolute must

Yeah, something like that.

As usual, this thread is heading off of the rails, and I seem to be at the switch. . . but, I have a similar story, although without the cleaning product angle, and this time I was the subject. I was up in Indiana shooting a sprint car race. I have a good friend (that I also sponsor) that races, and was taking a break at his hauler. It was a hot, July afternoon, so I reached into the ice chest, pulled out an ice cold bottle of water, opened it and took a bit swig. . . wait. . . this is a bit fruit. . . oh, WHY IS THERE A BURN?!?!? Too late down it goes. . .some kind of berry infused vodka. . . and there on the bottle, clearly labeled in tape, "Do Not Drink, this belongs to [name redacted]. It was the driver’s (now ex) wife’s beverage. . . .the driver was in the hauler watching me and just started rolling in laughter. . . it was enough to give me a nice buzz. . . . The driver still will give me a look if he sees me reaching into the ice chest after all of these years. . . .


Try Phosphoric Acid or CocaCola