How much access do you have? You can pump the oily water out with your bilge pump, but there will also be a disgusting thick sludge at the bottom, blocking all your limber holes. This will have to be removed mechanically; inother words, dig it out. You'll have to improvise you digging implements depending on the access.
Peter.
This is a job I've got to do in the next few weeks as well, so you have my sympathy. Once you've bailed as much sludge out as possible, using an old plastic teacup into a bucket, disposable nappies make excellent absorbant towels for wiping the slime off as many surfaces as you can reach. They can also soak up the last few drops but don't be tempted to leave one in the liquid for more than 20 minutes or it will explode. I find that a bucketfull of warm soapy water poured in afterwards helps to wash off much of what's left, but I can never get every last drop of gunge out.
On the plus side, I usually find what's in the bottom of the bilges replenishes my collection of brass screws and odd nuts and bolts.
Assuming it's still oil in the bilge water, and not a very thick sludge, there's now a product you can buy which absorbs oil but not water. It's available in white sheets about a quarter-inch thick, or in thicker pads for industrial levels of use. Ask around. DON'T pump out the bilge before you use it, because then the floating oil sinks on to the surface of the hull and tends to stick. Lay the oil-absorbing sheets on top of the bilge water, leave for a day or two, and you'll find the worst is gone. Lift them out and dispose of them (responsibly). We keep one sheet permanently under the engine to collect the inevitable drips from an older unit, so we never feel guilty about pumping out the bilges wherever we are. There seem to be about three manufacturers making it now, and some are not so good as others. Sorry, but I've got no records handy of who makes the one we use, and we're in the Netherlands anyway. Again, ask around. Maybe someone on the forum knows of the best British source. Hope you can find it.
Forgot to mention in my own post - yes, nappies are fantastic for the final stages. But I've never had one exploding! Thanks for the warning. An image worthy of Monty Python!
I've also had some success removing the oil from the top of the water by laying newspaper carefully on the water. It's cheaper than paper towel, which I have also used with success.
Peter.
We also use a "bilge dog" (at least that's what I think its called), a rolled-up mat that floats around in the bilge water and absorbs hydrocarbons. 3M make one commonly available at chandleries. Having suffered a couple of minor but irritating diesel leaks over recent years, I can say that these things are ok for mopping up residual amounts but if there's enough to form a layer on the bilge water, then bail that out manually and wash out the bilges because you'll need several of these and they're not cheap enough to throw around by the dozen. They absorb about 3 times their weight of oil, I believe.
chaps,
many thanks for all your ideas, I had already bought many rolls of kitchen towel for the job but will get back into tragos in falmouth for some cheap nappies,
regards, harry.
Not an experience to be repeated. They are filled with water absorbing gel, the same stuff you can buy from garden centres for hanging baskets. Unfortunately it expands enormously, far beyond the ability of the nappy's tissue envelope to contain it. At that point it's back to the shovel and bucket. Yuk!
did it today!!! only took about an hour with mainly cheap kitchen roll, into a black sack in a bucket. worked a treat and the bolts were not rusty at all but covered them in wd40 anyway.
thanks for all tips,
regards, harry.