HELP - Steel Callisto - Oil in Water Tank

[DistantDrum]

I need help on a number of counts due to the discovery of sump oil in our main water tank. This has contaminated both hot and cold water systems. One theory is that we have been sabotaged and a person unknown has put oil and petrol down our filler pipe. However, so far I have extracted at least 10 litres of black sump oil. Engine and Generators connect to the hot water system but both are okay. Also the oil extracted smells very strongly of petrol so is not from the ship itself. Currently I am still flushing the system with a product called hydrobreak which should eat the oil, this has been a long process and although getting better there would seem to be a long way to go.

The help I need is as follows:

1. The water tank is part of the keel of the ship and from the drawing sits on top of a ballast tank, presumably full of lead. Has anyone heard of a practice where a ballast tank was filled with sump oil to prevent corrosion – Maybe we have a cracked weld and oil is seeping up into the water tank.
2. Has anyone any contacts from the, now defunked, steel boat builders, Croft Marine, Stratford upon Avon.
3. Has anyone had a problem like this before and what do you recommend.

Thanks in anticipation. We are stuck in Gibraltar until we get this problem resolved.

 

[Ships_Cat]

1. The water tank is part of the keel of the ship and from the drawing sits on top of a ballast tank, presumably full of lead. Has anyone heard of a practice where a ballast tank was filled with sump oil to prevent corrosion – Maybe we have a cracked weld and oil is seeping up into the water tank.

That is a real possibility but would not regard the use of old sump oil for it as good practice myself - diesel is often used. Is also very bad design practice to have potable water separated from fuel or oil tanks by only one tank wall.

Once the source of contamination is identified and fixed, personally I would get a tank cleaning specialist company onto the job - might save alot of hard work, time and heart ache (obviously if a weld has to be repaired then may be easy for the yard or yourself to steam clean it as the first major step).

Can you not determine from the condition of the tank filler pipes and around the inside of the fillers if the oil was tipped down them? Would seem difficult for anyone to have got 10 litres down without some such evidence.

If you find someone has sabotaged your water perhaps you could consider valving the filler pipes inside the boat. Our own are actually combined with the deck drain on each side of the boat with valving under the deck to divert to the tanks (so you actually fill the tanks through the deck drain) - so in normal circumstances anything put down the fillers goes straight out the bottom of the boat into the sea and is impossible for any malcontent to pee down, or put oil or anything else into the tanks.

John

 

[Signed Out]

Sorry, I have nothing to add to help, but I just want to keep an eye in here re: the 2nd part of your question- I also have a Croft Callisto, albeit at 35', a one-off, and would like to know about any contacts. Am doing my bilges now, and going crazy with their surely unique nooks and crannies...
Jem.

 

[Wansworth]

Some designers fill voids with oil,so possiblity that oild could have been poured into ballast section,but it should have been good oil.

 

[Signed Out]

I think that may be the case with Croft/Callistos; just ahead of my (lifting) keel, on the top of the stub, is a screw-plug, that looks like it could be a filler for oil or similar. I seem to recall the previous owner telling me there's oil in there, but am unsure.

 

[absit_omen]

Hi, I remember DD from Hartlepool about 10 years ago.

I have a Premier Callisto 460 (stretched deck saloon 435). Shortly after buying her I noticed a plug on the top of the forward edge of the main water tank. I thought it may have been a dip stick. I unscrewed the plug and, to my horror, oil spewed out under pressure into the bilge. I had exactly the same thoughts as you about sabotage!

This was fresh, new, light coloured engine oil. I thought that it was floating on the surface of water so I took a pela pump and extracted it all (about 30 litres). I was completely puzzled. I then cut an inspection hatch in the top of the tank expecting to find more oil on the surface of the water. What did I find - pure water!

After discussing it with a few others (we were in Spain at the time) I realised that what I had been pumping out was oil from the void of a double skinned water tank. The oil was in there as a barrier to corrosion. Unfortunately, as a process of cutting into the tank I must have nicked the inner wall and I did get oil contamination in that tank.

Do you have an inspection hatch? Is the tank empty? If you have a leak you will have a film of oil on each surface of the tank. I got rid of my film by using bilge cleaner. Sounds dramatic I know but it really did work. I have since flushed the tank through about twenty times and, two years on and with no trace or smell of cleaner, we do not drink from that tank. BTW, I did not replace the oil as I determined that the risks of contamination in the future were too great.

It is a horrible situation to be in and you have my sympathy. Like you, my first action was to contact Croft and Premier but they are long gone.

 

[timiskaming]

callisto 460

I built the Callisto 460 in my garden after the hull was delivered to me from Croft Metzeradt, Stratford on Avon- NOT Premier Yachts, they only did some finishing work.

I probably know the solution to your problem. Just describe it in more detail so I can assess it.

njprescott@gmail.com

 

[ean_p]

errrr it was all such a long time ago!!!!

 

[KellysEye]

As others have said oil is used in steel boats to fill voids and stop corrosion. What I don't understand is that the oil smalls of petrol. It might be worth getting a sample chemically tested to see whats going on.

 

[Downsman]

errrr it was all such a long time ago!!!!

Ah! It was a lot of oil, I bet the poor 'ol kiddies still pumping..

 

[daveyw]

I am in the slow process of rebuilding a steel boat. It was my intention to pour molten lead into the keel. Weld a capping plate on with a stand pipe leading to a small reservoir at approx sea level then fill the keel with castor oil and maintain the head in the reservoir. The idea being to reduce electrolysis between steel and lead and in the event any keel damage/penetration, the sea water would be kept out by the head of oil... Or the rising level of oil in the reservoir would indicate an influz of seawater.
The stand pipe/reservoir would also allow for expansion of the oil in warmer climes