Author Topic: Under deck structures Fuel Compartment Question  (Read 1383 times)

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legaleagle

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Under deck structures Fuel Compartment Question
« on: July 06, 2021, 09:39:16 AM »
Hello,

I'm referring to pages 58 and 61 of the manual where Under-Deck Structures are discussed. 

The Note on page 61 says that All bulkheads should be limbered with exception of the the fuel tank compartment. 

On page 58 paragraph 6 , the manual says to strongly consider 2" or bigger gimble holes at the bottom of all bulkheads.

What is the difference between a limber hole and a gimble hole?

Should the fuel compartment not have either?

Todd j

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Re: Under deck structures Fuel Compartment Question
« Reply #1 on: July 06, 2021, 08:39:28 PM »
I cannot speak directly to your question, but some of us have built our fuel tank compartment to not communicate with bilge.   I think there may have been some changes to the dwngs since Dan B made some really great suggestions re: fuel systems in these boats. 

Brian.Dixon

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Re: Under deck structures Fuel Compartment Question
« Reply #2 on: July 11, 2021, 11:32:02 AM »
I cannot speak directly to your question, but some of us have built our fuel tank compartment to not communicate with bilge.   I think there may have been some changes to the dwngs since Dan B made some really great suggestions re: fuel systems in these boats.

I agree with this.  It's best to keep fuel fumes from creeping forward under the deck (or other structure) where it can build up and explode if an ignition source occurs, e.g. a sparky non-ignition-proof switch or a loose connection/terminator somewhere.  It's also best to use all ignition-proof electrical components too.  Finally, recall that ABYC standards say that the ONLY electrical connections allowed in a fuel compartment are for grounding/bonding and fuel level sensors, period.  It's OK for wires to pass through, though, if there are no connection/terminals in the fuel compartment - but make sure they are protected against wearing through their insulation due to vibration.

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Grady300

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Re: Under deck structures Fuel Compartment Question
« Reply #3 on: July 11, 2021, 05:34:04 PM »
I have a 3" plastic pipe starting inside the cuddy on the forward port side just aft of the cuddy window going into the top of my sealed fuel compartment. At the far aft end it leaves the fuel compartment down low and exits out the back near the tuna door. This allows for ventilating the sealed compartment. I also have down low a drain plug in case water ever were to get in there as well as a few deck inspection plates. You can see both of these on my most recent photos
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Brian.Dixon

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Re: Under deck structures Fuel Compartment Question
« Reply #4 on: July 12, 2021, 09:08:51 AM »

Haha ... I have no idea what a "gimble hole" is, nor why it is listed at 3".  I need to look that up and clarify the docs ... there are "limber holes", which I like to make at 15/16" ID so a standard boat plug will fit.  There are scuppers, which I like to make at least 3" or so and suggest using pipe plugs (with new stainless hardware).  There is a bilge drain, anchor well drains, and dry well drains.  And there are ventilation for fuel chamber if using plastic (requirements vary).  Did I miss anything?

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legaleagle

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Re: Under deck structures Fuel Compartment Question
« Reply #5 on: July 12, 2021, 02:00:14 PM »
Thank you for the input.  That really helped me figure it out on how I'm going to proceed.  Thanks

Todd j

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Re: Under deck structures Fuel Compartment Question
« Reply #6 on: July 23, 2021, 09:01:39 AM »
I ventilated my fuel coffin with a 3” OD stainless steel tube from outside the cuddy port side to the port transom locker where it will be dumped overboard.    Very easy and clean, it’ll last longer than the boat!