Diesel Tank Question

[stretch33]

Forum members, l have removed my engine pending a replacement Beta. The diesel tank was under the engine at the bottom of the bilge. The Beta guy had a look and suggested that this was the ideal place for the tank (its out at mo) When l took it out and drained it there was a fair bit of black sludge in the bottom. Had to pump it out as no drain. Now l had intended getting a replacement tank with the facility of having a drain tap and mounting it higher up. After the input from the Beta guy l'm confused. Yes l agree that it is a good spot for the tank being low down and 55 gals is a lot of weight. Against this is having no access to it for draining/service. The other point is its taken me an age to get all the crud out from under the tank which will again accumulate over a period of time if l refit the original tank. I think all the design had this tank in the bilge. I was going to use this space for spare anchor chain if l fitted a new tank. Your thoughts/opinions most welcome (hope this all makes sense) Phil

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[Chris_Stannard]

My tank is mounted, by the builder, where a bottom drain would normally be inaccessible. to over come this they have thoughtfully put a pipe in the tank which runs to the bottom of the tank, and has at the top of it a threaded connection for a pump which they also provide, but which is normally capped. Every couple of months or so, when the boat has been a rest for a couple of days, I pump a bit out of the tank by this means to keep the tank clean.
I think if the builder put you 55 gallons = about 450 lbs of diesel underneath your engine you will have to ballast if you move it elsewhere, so I think you would be well advised to adopt the pipe to the very bottom of the tank. Incidentally this means that you engine supply should be a bit higher so it does not suck up the crud. It also means you must make it a regular routine to suck some out.

Last thoughts make the tank of the right grade of stainless steel of the right grade, and dont forget to have an emergency fuel cut off valve fitted.

Good sailing

<hr width=100% size=1>Chris Stannard

 

[waterrat365]

Suggest you use an aluminum tank (which is what I have, but only 10 gallaons, alas!), mounted on neoprene rubber busings, to keep it away from SS, which can be a problem w/diesel. Tanks that size (55 gals) should have a proper baffle to knock down free-weight effect of floating liquids. Also, a proper clean-out at the top of the tank, oddly enough, for periodic inspections and cleanings. BTW, after cleaning the crud from your old tank, you may wish to re-use it provided it is free of corrosion and has a cleanout. Have it steam cleaned, then use a "Baja filter" to clean diesel before it gets in the tank,. and use a proper biocide (we use Biobor in the States) to knock down the algea - the source of the crude - before it has a chance to build up. This may be a controversial view, but its SOP in the USA, where warmer waters grows algea faster than in colder European waters. BTW, Baja filters are available from West Marine in the USA, and although pricey, work amazingly well. They actually get the water and particulate matter out before it gets into the tank. I often get a tablespoon of water out of a 5 gal jerry can. Best, Cliff Moore, S/V Pelorus, Keyport

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[Talbot]

I had a new tank constructed by TecTanks out of 9mm plastic with all the baffles etc. I created a full size model out of mdf to ensure that it would fit, and they built it exactly to size. The tank has a large inspection hatch at the top which contains all the connections so that I can get into the bottom of the tank if/when required. It is cheaper than stainless, not so liable to the bug, and lighter. Gets my vote!!

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[dickh]

Is it possible to fit a remote drain/pump out for removing the crud ocassionally and also to make an access hatch where you could get at it. 55 gallons is a lot of weight(approx 500lbs) high up.
This may be a cheaper option than a new tank - but make sure it is pressure tested if new fiitings are welded on for a drain/pump out point. Make the pump out point with a tap and then the pump with a flexible hose mounted higher up.

<hr width=100% size=1>dickh
I'd rather be sailing... /forums/images/icons/smile.gif

 

[Capt_Scarlet]

I had a water tank made by Tec-Tanks, and I was very impressed by their quality and service.

Built like a brick sh*thouse.

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