BLACK WATER TANK TO DIESEL

BIGUA

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Nov 6, 2016
33
HUNTER 380 RIO DE LA PLATA
Hi, I am preparing my boat for a large trip and need to improve fuel capacity storage and need some advice, is a Hunter 380 from 2001 , the black water tank is new (never used), I know that tanks for diesel are made from cross linked Pe and black water tanks from linear Pe, or something like that..... , anyone with first hand experience about using black water tank for diesel could comment ? appreciate any idea
 
Feb 21, 2013
3,916
Hunter 46 Point Richmond, CA
Sorry no first hand experience about using black water tank for diesel. I know the 380 has a 30 gallon fuel tank and 35 gallon holding tank so arguably conversion would more than double fuel capacity . Why not install additional fuel tank(s) in the aft lazarettes AND/OR carry multiple 5 gallon containers of diesel fuel strapped to the deck? That avoids plumbing to tie it in the fuel supply system to the holing tank and isolate the holding tank from the waste system and and future tank clean-out to revert it to waste service.

Fiberglass and polyethylene are common plastic materials for both holding tank and fuel tanks. You might find this article helpful on diesel tank material of construction.

 

BIGUA

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Nov 6, 2016
33
HUNTER 380 RIO DE LA PLATA
Thanks for your info sfbay, I just found a lot information here and other forums where explain clearly why is NOT possible to use Pe black water tanks with diesel, the point is I don't want to use 5 gal container on deck , seems the only one solution is find a proper place to put a flexible tank......but space is tighty in a 380....
 

Johnb

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Jan 22, 2008
1,301
Hunter 37-cutter Richmond CA
How much fuel do you carry and how much extra do you want to add?
 

BIGUA

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Nov 6, 2016
33
HUNTER 380 RIO DE LA PLATA
Hi Johnb, the H380 come with a 110 liters fuel tank, and for my planned trip I want to add the same qty at least, the Yanmar 3JH3E burn 2 liters / hour at 2.000 rev aprox with a flat sea ...I am looking a good place to put a flexible tank that don't take any useful space, i see you have a H37, nice boat !
 
Feb 14, 2014
5,783
Hunter 430 Waveland, MS
You might consider this tank that fits in available storage , but capacity will change as it conforms.
IMTRA CORPORATION Nauta® Flexible Diesel Fuel Tanks | West Marine

Marine Fuel Bladders - Auxiliary Bladder Pillow Tanks - Collapsible

But the key to any extra tank is the...

Fill and Empty method.
_______
I carry 12 gallons of diesel in my Port side Lazarette.

But there are many posts on securing cans safely on the weather deck.
Jim...

PS: I could store 10 gallons more in my swim platform storage hatch.
 
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BIGUA

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Nov 6, 2016
33
HUNTER 380 RIO DE LA PLATA
Hi JamesG161, thanks for the info, agree with you that need to keep in mind ALL details....specially fill and empty method.....but first find the place, second choose the flexible tanks for the job and final think the filling and empty method in real world......everything need to be sure and easy.....if it become a pain in the @$$ I will go with 5 gal containers on deck .....
 
Feb 14, 2014
5,783
Hunter 430 Waveland, MS
if it become a pain in the @$$
I like the $$$ in that reply.:facepalm:
But would like about 40 gallons extra too, for summertime trip i plan, to some remote islands.

You have given me food for thought.
I bet I could store that in the Starboard swim platform hatch and use this to transfer.

  • Transfer Pump, Marco TP-VP45-K

Jim...
 
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BIGUA

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Nov 6, 2016
33
HUNTER 380 RIO DE LA PLATA
Jim, that $$$ are the worst...haha, I iwill use a similar pump but conected to a cav 296 filter, H430 have lots of space !! nice boat
 
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Oct 26, 2010
1,456
Hunter 40.5 Beaufort, SC
  • Transfer Pump, Marco TP-VP45-K

Jim...
That pump delivers 11 gal per minute. Seems like way overkill for a sailboat for the intended purpose? Not sure I'd want one delivering that much that quickly. It will empty the portable tank very quickly. Why not opt for a 2 to 3 GPM pump or even less. I can't imagine a time when you'd need to transfer that quickly on an extended cruise. When you are cruising and the main tank gets to where it has how ever many gallons you want to put in a slow transfer could be initiated.
 
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Jan 5, 2017
2,172
Beneteau First 38 Lyall Harbour Saturna Island
3E04E02C-C324-4710-A130-8429992D2E63.jpeg We also have limited fuel capacity. Not wanting to limit storage we opted for jerry cans on deck. The extra 40 gals has come very handy a couple of times.
 
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Oct 26, 2010
1,456
Hunter 40.5 Beaufort, SC
yeah I saw that rate later... :yikes:
Told the Admiral it would empty my 6 gallon Jerry can in 1 second.:laugh:

This a better choice.
12v DC Transfer Pump 290 GPH

Just get the right hoses!

Watch out for drips after too.
Jim...
@JamesG161 I think I'd want to opt for something that is rated for diesel. The one listed says clean water transfer. I might also opt for something that would survive the marine environment a little better. Not knocking Harbor Freight but I doubt that would be a good candidate for something that sits "unused" for much of the time and then needs to operate when it needs to operate.

For this application I might choose a high capacity hand pump like used to set on the top of 55 gal drums (but smaller of course.) I don't imagine there will be a lot of "head" associated with this application so capacity at low head, high flow conditiosn would be ideal. I wouldn't expect to be using this "extra capacity" very often and and hand operated rotary pump would probably be very reliable and nearly bullet proof. When you need this capacity, you generally "really need it." Just my thoughts as a Navy guy who likes the Kiss principle as well as the "sailor proof" option.

OBTW - how did the new rudder work out? I may be shopping for one the next haul out. I can drive mine down to Foss Foam and they will rebuild it for a pretty reasonable price. PM me
 
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Jan 5, 2017
2,172
Beneteau First 38 Lyall Harbour Saturna Island
Michael, looks like you and Bev have been relaxing on the cabin top. :biggrin:
Yeah, the hook is down and it’s time to relax. Notice the blue sky and lack of snow.......just to show we get nice weather( sometimes)
 
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