Fuel tank filling options

Our aft deck needs to be replaced because of unattended leaks at the deck fills.

There will be a permanent rain cover/bimini over the aft deck, so I was thinking it would be possible to fill the tanks by reaching into the open lazarette hatch and doing away with deck fills altogether. The fill pipes are fairly accessible without having to over reach or crawl into the lazarette.

Sound doable? Any rules or regulations against this? Any other options out there?

Transport Canada fuel system regulations;

https://www.tc.gc.ca/eng/marinesafety/tp-tp1332-section7-2172.htm

I set up my tanks with corners accessible by opening a cockpit hatch. On top of the tanks are tractor trailer fill caps, about 3" dia. Makes filling a breeze and also allows dipsticking the fuel level. And when filling, vent is not in play as it vents through the fill opening. Never a vent spill.

One of the best features I built into the boat.

Ski in NC said:

I set up my tanks with corners accessible by opening a cockpit hatch. On top of the tanks are tractor trailer fill caps, about 3" dia. Makes filling a breeze and also allows dipsticking the fuel level. And when filling, vent is not in play as it vents through the fill opening. Never a vent spill.

One of the best features I built into the boat.

Click to expand...

Thanks

Ski, I agree, direct deposit is the best. And a big fill hole is great. This is my personal preference to. BUT, its goes against every regulation known to us.

kulas44 said:

Ski, I agree, direct deposit is the best. And a big fill hole is great. This is my personal preference to. BUT, its goes against every regulation known to us.

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As far as the Canadian rules in the Transport Canada link above, I think this is the big one;

7.3.5.1 The fuel tank venting system shall:

1. discharge fuel vapours overboard;
2. not allow a fuel overflow to enter the vessel

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They do mention requirements for deck fills, but don't say deck fills are mandatory.


Seems logical to dispense with deck fills, thereby avoiding deck leak issues and water accumulating on, under, or in fuel tanks, which can be an issue with older boats.

WE Deep Sixed the deck fills and lowered the fill hose to accept a pipe nipple and cap.

The fill hole is covered with a 6 inch bronze deck plate , as it is in a walked on area.

A plastic plate would be fine if no foot traffic.

Even if the bronze cover were lost no rain or sea water would enter the fuel fill because of the shape of a pipe cap.

I don't see the problem.
The fill hole in the cockpit deck is like any other hole in the deck. The core has to be properly sealed with epoxy and the filler fitting sealed with butly tape or similar. Problem solved. No different from the deck hole for your windlass, thru-hulls, antenna cable, etc.

If you want to be double sure you have no leakage onto iron tanks, use an elbow and offset the filler cap so it isn't above your tank.

AusCan said:

I don't see the problem.
The fill hole in the cockpit deck is like any other hole in the deck. The core has to be properly sealed with epoxy and the filler fitting sealed with butly tape or similar. Problem solved. No different from the deck hole for your windlass, thru-hulls, antenna cable, etc.

If you want to be double sure you have no leakage onto iron tanks, use an elbow and offset the filler cap so it isn't above your tank.

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You're right and I'd like to think I would have attended to the leaks as they came up, but we're the third owners of a boat built in 1982 that has lived it's entire life on BC's wet west coast.

Buying an old boat means having to deal with issues on a triage basis (especially when doing major house renovations at the same time) and there were more important things to deal with first.

So, if it needs a major overhaul and things need to be rebuilt and/or replaced, why not do it in a much better way?

kulas44 said:

Ski, I agree, direct deposit is the best. And a big fill hole is great. This is my personal preference to. BUT, its goes against every regulation known to us.

Click to expand...

What regulation prevents this? Not trying to argue, just curious.

I've got less risk of getting diesel in the bilge fueling than I do being sloppy on filter changes. And way less chance of getting diesel overboard.

My fuel vents run up the side of my house and vent above the roof. The fillers are on each side deck and have a large 3" cap that I remove with a pipe wrench. The tops of my tanks are also my decks.

On your "yacht" you could run nice shiny stainless pipe up the house for a vent over the roof and lose for ever any overflow issues. If you use robust material it could even be a useful grab rail.

I'm going to have to get up to your area one summer - my slip mate explored your inlet last summer and enjoyed it thoroughly.

Xsbank said:

My fuel vents run up the side of my house and vent above the roof. The fillers are on each side deck and have a large 3" cap that I remove with a pipe wrench. The tops of my tanks are also my decks.

On your "yacht" you could run nice shiny stainless pipe up the house for a vent over the roof and lose for ever any overflow issues. If you use robust material it could even be a useful grab rail.

I'm going to have to get up to your area one summer - my slip mate explored your inlet last summer and enjoyed it thoroughly.

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Interesting vent line thought given a fuelling experience I had this winter...which is another reason for the fuel tank system re-think. It was -10 Celsius with a brisk north wind and swirling/blowing snow had plugged one of the vent lines. Grrrrrr & Brrrrrrr!!!

Yes, there's tons of places to explore off the main channel, but don't spread the word too much

I'll have to dig it up, its in one of Gerrs book, something like all overflows must exit outside of the boat, IIRC. I think its a stupid regulation also and have never heard of anyone being cited for not doing it. However, on a coast guard inspected boat it would be required.

Greetings,
Mr. MM. Yes, 7.3.5.1 states the lawful design of a tank vent but it does not say one needs a vent unless such a fact is mentioned elsewhere...

Words are slippery things. If you read the vent requirements in post #6, it could be argued that a vent doesn't have to go overboard, only the fumes do, and that any fuel from overfilling can flow to a scupper and then overboard as long as it can't flow back "into" the boat.

"No different from the deck hole for your windlass, thru-hulls, antenna cable, etc"

All of which must be re bedded on a sked to keep any wood under from dissolving .

5 years is great ,8 stretching it , 10 way overdue.

Goop, glop or thick tape are not forever!

Inside fill would seem to violate the reg's ref in post #2

"7.3.4.3 Deck fill plates:

shall be located at least 380 mm (15 in) from any fresh air intake for gasoline systems;
shall not permit a fuel overflow to enter the vessel; and
shall be labelled as indicated in section 7.11.2."

"7.3.5 Ventilation of Fixed Fuel Tanks
7.3.5.1 The fuel tank venting system shall:

discharge fuel vapours overboard;
not allow a fuel overflow to enter the vessel;
minimize the accidental entry of water; and
prevent pressure in the tank from exceeding 80% of the rated pressure of the tank."

I'm assuming your vents are exterior now and would remain where they are so vents probably not a problem but fill??

I'm assuming you need to repair the area around the existing fills and doing it correctly to prevent further problem (and leaving fills where they are) no more work than filling / fairing & finishing the holes.
Sealing correctly (w/ 4200 or butyl tape) should prevent further leakage.

Here in the US, I sometimes run commercial boats that used to be a commercial fishing vessels subject to inspection. Those and other commercial vessels also also all have deck plates over fuel fills.

They do vent overboard.

Bacchus said:

Inside fill would seem to violate the reg's ref in post #2

"7.3.4.3 Deck fill plates:
shall not permit a fuel overflow to enter the vessel

7.3.5.1 The fuel tank venting system shall:
discharge fuel vapours overboard;
not allow a fuel overflow to enter the vessel

I'm assuming your vents are exterior now and would remain where they are so vents probably not a problem but fill??

I'm assuming you need to repair the area around the existing fills and doing it correctly to prevent further problem (and leaving fills where they are) no more work than filling / fairing & finishing the holes.
Sealing correctly (w/ 4200 or butyl tape) should prevent further leakage.

Click to expand...

The damage (sponginess) in the aft deck is quite a bit more extensive than just around the fills.

The reason I've left it this long is because the aft deck needs to be replaced, so why not replace the fuel tanks and solve the blocked vent lines at the same time? Big project (for me anyway) so smaller projects have been ticked off the list in the meantime.

Anode, a TF'er who hasn't been around here for a while, did a complete refit of his 30' Sundowner Tug and here is what he found contributing to the soft aft decks...mysterious holes through the aft deck hiding under the storage boxes;

https://www.facebook.com/chip.estab...06927992.176048.509307992&type=1&l=a47ad998a8

RT Firefly said:

Greetings,
Mr. MM. Yes, 7.3.5.1 states the lawful design of a tank vent but it does not say one needs a vent unless such a fact is mentioned elsewhere...

Click to expand...

If your fuel tank doesn't have a vent, the engine won't run for very long. You will also have trouble putting fuel in the tank if air can't get out.

Regulations or not, you don't want spilled or overflowed fuel inside the boat. Think about it before you redesign things.

Greetings,
Mr. WK. Hahahahaha...Doh! I'd forgotten about that. Thanks.

My tanks have normal vents like any other tank, it's that the fill caps are on the tanks themselves. When filling, the vent is not in play, it vents through the big fill opening. When running the vent is in play.

I probably am violating a rule by being able to spill fuel into bilge, but I like better this way. Filling normal tanks almost guarantees spilling fuel. Never had a spill on mine.

Ski...I don't think so as my employer has a fleet of boats that is similar.... cant imagine with all the USCG stuff those boats have been through, they haven't been flagged.

Greetings,
Mr. MM. I like the idea of a high vent. How about mounting your fill cap (large) in a recess just above deck level on the inside of your transom and running your vent inside the transom to a fitting outboard and high up against your gunwale? The vent will be higher than the fill and any spillage, if there EVER is any will be on deck and not out the vent.



Fuel fill recessed similar to oval hole in the 3 o'clock position. Photo courtesy of Mr. Hendo's fantastic rebuild of Axe post #1992. Thanks Matt.

RT Firefly said:

Greetings,
Mr. MM. I like the idea of a high vent. How about mounting your fill cap (large) in a recess just above deck level on the inside of your transom and running your vent inside the transom to a fitting outboard and high up against your gunwale? The vent will be higher than the fill and any spillage, if there EVER is any will be on deck and not out the vent.

Fuel fill recessed similar to oval hole in the 3 o'clock position. Photo courtesy of Mr. Hendo's fantastic rebuild of Axe post #1992. Thanks Matt.

Click to expand...

I see, and envy, those elevated fillers on a late model Halvorsen IG 32 on my marina.
When I had my teak decks redone I floated the idea of elevating the existing flush fills by a centimeter so any water on the deck was below filler level, got talked out of it by the yard. Probably saved some stubbed toes.

Make a nice aluminum or stainless box with a top that seals and some sort of a latch (or a lock). Put the filler with its cap in the box and a drain in the bottom of the box that drains spilled fuel back into the tank. Tee the vent so that one branch of the tee terminates in the box and the other tee goes to the roof with a 180 degree bend and an insect screen. Any fuel that exits via the vent will drain back into the box/tank and vapours will exit up high where delicate noses are not insulted.

Mount the box flush in the deck or flush in a wall or in the lazarette or anywhere that it is convenient to refuel. Spills will be caught in the box and returned to the tank, overflows likewise and the Carbon-nazis will sleep a peaceful night.

I think this is called a fuel chest?

Run the vent hose up inside a stanchon.

Thanks for the design options...all have merit and will be pondered accordingly