CNG availability on the Great Loop

[boatpoker]

Originally Posted by captstu

There seems to be some confusion on this thread. Compressed natural gas (CNG) is somewhat safer than propane because it is lighter than air doesn't present explosion hazard if it leaks in the bilge. But it is stored under high-pressure as a gas in the tank that must be strong enough to withstand the pressure. Special handling is required to fill the gas under high-pressure.

Propane is a liquid under modest pressure and can be stored in a tank without extensive safety precautions in the design of the tank. Propane tanks are quite inexpensive and are generally exchange rather than refilled because it is easier for retail outlets to store and return the tanks.


Compressed natural gas systems can be converted to propane relatively easily, usually by just changing the orifice a small part in each burner. Conversion of propane tanks to CNG is not practical because the lines design for propane are not designed to handle the pressure of CNG.

If you were contemplating a long trip outside of the CNG refill area in the United States, you might consider just purchasing enough CNG tanks to last the last of your trip. The tanks are quite strong, leaks are very rare, and the cost of the tanks may be Worth the effort you avoid having to hot for a welding supply or gas supply house they can fill your tank.

I don't see any confusion here at all, the posts are quite fair and accurate and while the changing of a few orifices is not a big deal, building a proper storage system for propane tanks can be difficult and expensive.
Safe Boat Propane Systems

[Mike Crothers]

I can only speak for the East Coast, we have a 40' Hunter Legend and have an adaptor to fill the tanks for just pennies but it is a bit dangerous to do it yourself due to the pressure difference between automobile fill stations and the CNG tanks used on Hunters. (2,200psi vs 5000psi)

With many people getting out of CNG we had no trouble buying extra tanks, 5 total, so we could go several months between fills. You can exchange tanks in Annapolis but it is expensive. There is a utility company in Florida that will fill them for a reasonable fee. The website Active Captain could tell you about other Marinas that offer CNG.

So while you can keep the CNG it is a bit of a pain especially if you live on board and use significant gas. This may change in the future as the surplus of methane gas floods the market.

[BobLocal60]

When we got our latest vessel, The prior owner had made an adaptor for the CNG tank, Owned her for 3 + years and only filled the tank once... only cost $2.50 to fill as it is available in Pensacola as a by product of the landfill at $2.05 per gallon, only issue is the station is self serve and they put a $150.00 or $250.00 hold on my bank account for a few days till the $2.50 charge cleared. It did take several calls then I just drove out to the station that all the county vehicles use and did it my self.

[donradcliffe]

A scuba sized cng tank holds about 3.3 lbs of cng at 2000 psi. The standard BBG 5 gallon propane tank holds about 20 lbs of propane. Both have about the same BTU/lb, so the propane tank will last 6 times as long in your boat.

We took a full cng tank on the transpac. There was no wind and we ran out of cng on day 12. Cold food is not fun.

A 20 lb propane tank lasts the two of us 90 days.

Propane is readily available everywhere.

Your choice.

[savoir]

Beats me why anyone would want to cook withCNG no matter where they are headed. Sales outlets are too few and far between while on the other hand propane is everywhere. I have never seen CNG at a fuel dock or at a nearby gas station. One 20lb propane tank should last you 3-5 months depending on how many people you are cooking for so one fill per summer is quite doable.

I fill mine at the local Ace Hardware once a summer. Too easy.

[Bill Seal]

If you don't have room for a spare LPG tank, U-Haul sells one with a float actuated fuel gauge for about 30 bucks, so you can re-fill it before it runs out in the middle of your steak dinner.

[WSMFP]

Originally Posted by savoir

Beats me why anyone would want to cook withCNG no matter where they are headed. Sales outlets are too few and far between while on the other hand propane is everywhere. I have never seen CNG at a fuel dock or at a nearby gas station. One 20lb propane tank should last you 3-5 months depending on how many people you are cooking for so one fill per summer is quite doable.

I fill mine at the local Ace Hardware once a summer. Too easy.

It's 85 cents to fill and it's making a come back since many buses, heavy equipment and delivery trucks are converted to CNG.

Fueling Solutions - Blue Gas Marine

[a64pilot]

I would want it for the safety aspect, but will wait for it to become more available before I switch
Like gasoline engines propane makes me nervous. I believe the danger can be mitigated by inspection and good practices of course, just I think CNG is less hazardous

[rwidman]

If CNG is unavailable where you cruise or live, the safety factor doesn't really matter. Propane is safe when installed and used correctly and of course it's available nearly everywhere.

There's a current thread asking how to patch a propane connection. This is a good example of unsafe propane practices. For this person, CNG (or a wood stove) would be better. For those of us who understand the importance of doing things the right way, propane works fine and is safe.

[ctl411]

Do a search of your intended cruising area for car CNG filling stations. If you find sufficient for you, Google and or YouTube the adapter to fill your tank. If you are knowledgeable enough to run/maintain a cruising boat you can refill your own tank. If going out of CNG area you can also change the Jets in your stove to run propane.

[donradcliffe]

3600 psi car CNG filling stations, boat tanks designed for 2200 psi. What could possibly go wrong??

[ctl411]

Originally Posted by donradcliffe

3600 psi car CNG filling stations, boat tanks designed for 2200 psi. What could possibly go wrong??

Yup if you can't/won't build a proper adapter regulator then don't do it... That's why I said if you can not just do it.

[rwidman]

Originally Posted by donradcliffe

3600 psi car CNG filling stations, boat tanks designed for 2200 psi. What could possibly go wrong??

The people giving advice here aren't the ones living with the consequences. And some are not the sharpest crayons in the box in the first place.

[boatpoker]

Originally Posted by rwidman

The people giving advice here aren't the ones living with the consequences. And some are not the sharpest crayons in the box in the first place.

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