SMELL IN BOAT

[bunyip]

We have a Maxi 84 (1978) and there is a smell of hot oil/exhaust/diesel which permeates sleeping bags, cushions, upholstery etc. When ventilated with hatches open the smell disappars from the cabin but is there the next time we open up.The boat is dry and there are no obvious leaks from the fuel tank,exhaust etc. We have tried various air fresheners without success. Any suggestions?

 

[chippie]

If you have a blower in the engine compartment make sure it is sucking air out rather than in, otherwise the compartment becomes pressurised forcing fumes through the boat. A domestic upholstery deodoriser may be some help.

 

[Twister_Ken]

Gunk

My boat from 1980 suffered similarly. The engine was replaced last year. While the engine space was empty I crawled in and excavated a bucket full of oily gunk, which seemed to be 20 years worth of dust and dirt that had gravitated to the lowest part of the bilge, and soaked up every drip of oil or diesel that had ever found it's way down there. A thorough clean up, followed by a month or two of emptying a few gallons of freshwater/fairy liquid in the bilge, and then pumping it out after an hour or two's sailing had sloshed it around, and the problem has now gone,

 

[Chris_Robb]

Re: Engine Room Blowers

You suggest that engine room blowers are for extracting. They are normally there to ensure that there is enough supply of oxygen. The engine itself will act as a powerfull extractor fan as it sucks in air.

It would be very wrong to extract air, except on a petrol engine room - prior to starting up. By reversing this air you may well cause your engine to produce black smoke at speed.

As for the smell, you may well have some old oil which has degraded in the engine room, which is supplying this smell. A really good clean up would be worthwhile with a grease buster.

 

[Guest]

Re: Gunk

Absolutely .....

MY perkins was lifted last winter for new mounts etc. and the mess underneath was unbelievable. But in all the time of looking it never appeared to be so bad.

So you can wipe away as much as possible with rags / handfuls of tissues etc. Then spray with oven cleaner ..... Leave it for a while. Then wipe away and then wash it all down with water .... saltwater's ok if you wipe out well and then rinse off with fresh.

That way you'll have the cleanest, sweetest bilges you've seen for a long time !

Then as another says ..... washing up liquid ... few squirts in the bilge and let the water slop around for a bit that collects from condensation etc. before pumping out.

 

[bunyip]

Re: Gunk

Thanks for the responses so far - My boat does not have a deep bilge so the gunk solution is not going to help - i am interested in the idea of a blower and did in fact purchase an in line one to fit in one of the two engine compartment breather ducts but then discovered that the engine control cables are running through one and the bilge pump tube through the other! Could it starve the engine of air if I am able to fit the blower? or would a vent to allow air to be drawn into the engine compartment from the boat be ok? Another thought I had was that the exhaust system tubes which look like rubber may have become porous like some toilet tubes?

 

[chippie]

Re: Engine Room Blowers

My understanding of blowers is that they create an airflow .The air doesnt know if it is being sucked or blown.As long as a there is adequate ducting to allow air in and out it doesnt matter much which way the fan is working.The point was that avoiding pressurising the engine compartment was also avoiding seepage of any fumes present getting to the rest of the hull. It would be a mighty extractor that would overcome the engine's own rate of air intake to cause it to run rich.

 

[Chris_Robb]

Re: Engine Room Blowers

The problem with most engine installations is that in trying to sound proof the compartment, one also stops up the free air circulation.

Most blowers also only work one way, ie those with the horizontal vanes as opposed to a propellor fan, so unless they are mounted the other side of the bulkhead, will make lots of noise,but move very little air.

The reason for my posting was that I actually tried to reverse the air to extract 70hp Perkins) and did get black smoke on high throttle settings. Putting them back to the correct way cured the problem.

The engine will do all the air extraction you need and move vastly more air than an extractor could ever do.

 

[dick_james]

The problem may not be occuring when the engine is running as previous contributors describe, the engine acts as a good extractor. However, when you switch the engine off there is no air flow at all and the hot engine sits there quietly with the attendant smells seeping through the boat. Try switching an engine fan (sucking out) on for half an hour until the engine cools down a bit.

 

[bunyip]

Thanks for this contribution - you make a valid point about the period after the engine has been stopped - I had thought of using an extractor fan while the engine is going but you idea makes more sense - the only concern then is the risk of running my service battery down and having to run the engine to charge it up again!!