Gas Tank Rigging Advice/Grounding? 1977 18' V-Hull

Stringers, bulkheads and transom are finished! Just laid down 3 coats of Totalboat bilge paint, came out great! The paint was super easy to apply, set up quick and is very thick. Moving on and getting ready to set install the tank I had built; 69" long, 16" wide, 8" high = about 37 gallons. She will sit between the stringer and I will be using some heavy duty through bolts to secure it to the stringers via the four tabs. There is a gap between the stringers and I will tab so I will be using a few pieces of starboard to make the tabs flush with the stringers. I will also be using 1/2" neoprene strips for the bottom of thank for cushioning/bracing between the bulkheads. Also will probably use two pieces of starboard to hold the tank down (width wise/using some screws through the stringer) to prevent the tank from wanting to lift upwards (still debating on this approach). Any input /thoughts are welcome!

Anyways, my real question here is to do with grounding. The tank I had built came with a welded on tab that is for grounding. I've read countless articles on this and am still at a loss. From what I gathered, you want to have a grounding wire at the fill cap secured via a screw to the bottom of the fill that is in the gunnel which runs from the tank to a grounding point. And also you should have a grounding connection via the fuel pick up unit. Should one wire run to the installed grounding tab and that be the one coming from the fuel fill?

Full disclosure here, a few of my buddies are boat builders and will certainly be lending a hand with this aspect if I can not figure it out on my own. I really want to build out the entire boat myself but I rather be safe then sorry. Any input here is welcomed and thanks for your time and effort! Some pics of tank below.

 

You need: (to be ABYC compliant which means that this is for your own safety)

1) an anti siphon fitting on top of the draw line

2) Two clamps for the filler hose, a marine type with the band and screw being stainless, 1/2 band width
(a recent thread I had suggested that you use two clamps on fuel lines WHICH is not required under ABYC BUT, for the small expense of extended fuel fittings, spuds which allow enough room for 2 clamps, I would recommend them)

3) Proper marine grade filler hose, vent hose and fuel lines. There are specific permeability requirements which do not always apply to automotive fuel lines. Meets SAE J1527

4) It appears from the pictures that the gasket under the sender unit is rubber. It cannot be either all cork or the rubber and cork mix. They disintegrate over time.

5) Ensure that your vent line has a loop at the top before it it attached to the vent to hull fitting so that any water that enters the vent will drain overboard. The screened type can easily pass water into the lines. This type is probably not allowed any more. Ensure that the fill hose does not have a dip where fuel will accumulate when filling or the fill process will be very slow.

6) Any wiring in the boat should be done with marine grade wire which is automotive wire where each strand is tinned to reduce corrosion

7) Since the writing of the manual that I have, to limit fuel vapors getting to atmosphere, there are new rules regarding vents and fills. Basically, they only vent when fuel vapor hits a limit as compared to always venting to atmosphere.

 

What is the grounding for ?

 

Barry once again, great input here, thank you very much for your time and effort! I certainly have some things to mull over here. I just may rely on my boat builder friends here for the tank install. Thanks again!

 

All metal components, vent and filler if metal, tank tab, get grounded with the negative sender wire to the ground bus for the start battery.

corrections welcome

 

I don't like metal filler fittings, you may get a spark, otherwise what can go wrong ?

 

well, they have them at all the fueling stations across America; and the inlets are metal as well

 

The purpose of grounding the fuel system in a boat is to reduce the chance for a difference in voltage between the fuel system and any other objects that carry a different voltage which can create a spark as the two items get close to each other.


There are at least three situations (probably more) that could occur between the boat and the fuel hose.

1) A transient stray current ( and subsequent voltage) within the marina caused by improper polarity wiring from say a 120 or 240 volt service. This could include wet receptacles.
2) Static electricity which can be produced due to the fuel moving down the hose and creating the potential difference, ie difference in voltage to create the spark at the fuel fill.
3) Stray currents within the boat that may occur within the grounding side of boat wiring> ( I suspect this is why ABYC requires the ground wire for the filler neck, sender and tank have a dedicated to ground wire though it appears
to be a bit at odds with stating that this wire can be connected to a common bus?)

{Is there a situation where the wires carrying current to other equipment in physical parallel proximity with ground wires experience an induced current and hence voltage in the ground wire and raise the absolute voltage in the ground wire>}

Static electricity can be developed by the fuel simply moving down the hose and this static electricity can be transferred into the fuel in the tank as well. Static electricity can exist on non conductive materials or conductive materials
that are not grounded, but not on conductive materials that are properly grounded as the PD will in essence go to a zero PD

High temperature which reduces the vapor pressure of say a high volatile fuel, gas as compared to diesel, and air entrainment increases the chance of ignition if a spark occurs.

It is best to touch the marina fuel fill hose to the filler on the boat prior to opening the fill cap and then ensure that the pump fill handle is in contact during the fill to ensure that a spark will not occur when pulling the pump fill handle
is removed.

 

And I dare say they are grounded, I have always been careful, rightly or wrongly, of keeping say a metal jerry can away from a metal filler opening, by using a plastic funnel.

 

Look at tank requirements here Boat Building Regulations | Boat Fuel System https://newboatbuilders.com/pages/fuel.html
Look here to see diagrams of fuel tank installations: the top one is the current Coast Guard , EPA, and ABYC standard. The bottom image is the simpler Coast Guard and ABYC standard prior to January 1, 2012. see below https://newboatbuilders.com/images/Fuel_Tank.jpg


Grounding is not all that complex. If your have a metal fuel fill fitting, then you need to run a wire from that fitting to the grounding tab on the tank, and then run a wire from the ground on the tank to the boats Ground which is normally the negative battery terminal on most small boats. Some may have a separate grounding buss, that all ground wires lead to, and the grounding buss is connected by a single wire to the battery negative. If the Fuel fill is plastic, it is now recommended by ABYC and the Coast Guard that you do not run a wire to the Fuel Fill.

As stated before by others the wire should be marine wire, usually labeled UL 1426. It does not have to be tinned, but tinned is better and tends to last longer. But I have some untinned wire in my boat that is over 40 years old and still perfectly acceptable.

By the way, anti-siphon valves are only needed if the fuel lines run down hill. If the fuel inlet on the engine is higher than top of the fuel tank you don't need one.

 

Thanks for the reply, this is great information!

 

Within the last two years, this picture is one that I would have agreed with and responded to a thread with this set up in mind. A contributor, new I think, provided a new picture that said that the new ABYC guidelines now require
a carbon canister and a fuel system that only vents when a certain pressure is hit. I could not find this thread that came with an accompanying drawing.
I was able to find this excerpt though and it appears that the USCG states that the EPA reg below it is actual law. Ike you would know better

I will post a link to a document that may or may not be up to date but it is this document that the info stated below came from. There is a picture of the Traditional Installation, the one that I thought was still in effect as well as a new picture of the complaint installation
Link as above https://www.uscgboating.org/assets/1/AssetManager/ABYC.1002.01.pdf

IT’S THE LAW - USCG: 183.507 General. Each fuel system component on a boat to which this subpart applies must meet the requirements of this subpart unless the component is part of an outboard engine or is part of portable equipment.

IT’S THE LAW – EPA: 1045.1 Does this part apply for my products? (2) The requirements of this part related to evaporative emissions apply to fuel lines and fuel tanks used with marine engines that use a volatile liquid fuel (such as gasoline) as specified in 40 CFR part 1045.112. This includes fuel lines and fuel tanks used with auxiliary marine engines. This also includes portable marine fuel tanks and associated fuel lines. The boat manufacturer, not the manufacturer of each component, is required to certify each boat as complying with this regulation. Component parts of outboard engines and portable equipment, such as a self-contained gasoline engine generator unit, are not covered by these USCG regulations. Outboard engines, their fuel systems, along with other spark-ignition marine engine systems are covered by the EPA regulations. The Equipment Standards of this regulation appear to impose requirements, and consequently certification responsibilities, on component manufacturers including inboard engine manufacturers. This is not the case. The boat manufacturer is responsible under these regulations and must certify compliance. Purchase orders can stipulate that component manufacturers provide affidavits of compliance which a boat manufacturer may choose to recognize as supporting evidence in certifying the entire fuel system.

 

If this were a manufacturer I would have specified the USCG/EPA/ABYC required configuration. But the question arises; do the USCG and EPA requirements apply to a DIY boat built for ones own use and not intended to be sold? The USCG regulations are very clear, they apply to boat manufacturers. The EPA regulations are not so clear, but could be interpreted as applying only to boat manufacturers, fuel systems manufacturers, repair shops and so on.

However, if the DIY boat builder wants to comply they certainly can, and the parts are readily available from marine retailers. Below is a link to the newer requirements.

https://www.uscgboating.org/assets/1/AssetManager/ABYC.1002.01.pdf
Also my page on fuel systems Boat Building Regulations | Boat Fuel System https://newboatbuilders.com/pages/fuel.html
The diagram is on the same page as the pre-2012 diagram and reflects a fairly standard way of complying with the EPA standards. There are alternatives, outlined in ABYC and by some fuel system suppliers.

 

Hi Ike
An interesting facet regarding DIYers being required to build to ABYC/USCG and or EPA specs or not. A query then would be this: If the OP rebuilds a boat he would have a HIN number and probably be able to apply for insurance without a survey.
If unable to apply without a survey, would a surveyor be required by law then to point out the deficiencies wrt to USCG and or EPA to give to the insurance company prior to binding? And if non conforming and the insurance company
binds, then do they take responsibility if the non-conforming part say causes a fire and creates damages?

While I am certainly not a lawyer, my limited understanding is that in order to be sued for damages, there must be negligence. My limited understanding of negligence is that if you know that you purposely did not conform to
accepted practices or law, you are negligent OR if you have done something incorrectly that you should have known that it is incorrect, this is also negligent leaving exposure to suit.

Ie a person driving a car at the speed limit on icy roads, creates damages, should have known that it is unsafe and therefore is negligent.

Anyway, some fine points here. But with insurance companies and a 20 page description limiting what they cover or rather what they do not, the Exclusion Chapter, a person has to be comfortable with what they do and bear the consequences

 

Interesting question. I'm not a lawyer either. The only parts of the law I know fairly well is the stuff I enforced. The writers put sneaky stuff into laws and regulations, that if you don't read it carefully you can make a mistaken interpretation. Anyway, As far as I know a surveyors only responsibility to report, is to his client or employer.

Probably. but it would most likely be only liability. I can only speak from experience. When I applied for insurance on my 1972 Sea Ray, they had me do a self-survey. They provided a form and instructions and wanted lots of pics, but it really didn't matter because they wouldn't have provided damage insurance anyway.

As for negligence, that's pretty much up to the jury. I can recall stories Peter Ball told me. He did a lot of expert witnessing, mostly for the builders, and some of the things the jury found negligent were, to me at least, baffling. I suppose if you built your own boat and installed the fuel system by the old standard, and it went boom, you could be considered negligent. But the current EPA standards are only emissions standards, not safety standards. The USCG safety standards have changed only in respect to the evaporative emissions, and the slight amount of pressure allowed in the fuel system. (something we strenuously objected to) .