The Dreaded CNG to LPG conversion

[SV ALL IN]

Good day

I'm newer to this forum but have searched them before, but if this is already posted sorry and send me the link...

ok so i debating to convert to lpg or not, i have cng now.

Crusing: will be leaving florida for the bahamas and than the virgins for 6 months all told.

the options as i see them
1. buy additional cng tanks and carry extra
2. change the orphasas and do i full convert approximate cost is $1000 or so i think
3. buy small lpg burner that isn't attached to the boat

would appreciate any feedback, personal stories, or anything that can help.

thanks

brad

 

[Alan]

I would check first to see if CNG is available in your destinations. Personally I would prefer to carry an additional CNG tank than convert. CNG is a lighter than air gas and poses much less explosion threat than does propane. Of course when handled properly both work equally well but the added expense of converting and the loss of cockpit storage space would put me off propane. To its advantage propane is far more available for refill.

 

[Benny17441]

One of the drawbacks of CNG as a fuel for cruising boats is the lack of CNG availability in foreign countries. I don't think you will find any in the Bahamas or at least let me say I have never seen any. Many folks are having difficulty here in the states finding tanks and and getting them filled. The CNG stations mostly service converted automobiles and trucks and most will refuse to fill or allow the use of adapters. Im sure you know about the characteristics of Propane and CNG that while one tends to collect the other one disipates having a much lower risk of reaching explosive concentration. If you can find additional CNG tanks and get them filled that would definitely be your best bet. I'm leary of the use of camping propane stoves on a boat as they do not offer the necessary safeguards to be used in enclosed spaces. In lieu of a conversion I would recommend you get a two burner non pressurized alcohol stove. Origo makes a fine stove and you may find one for around $350. Denatured alcohol can be purchased by the gallon at Home Depot or any hardawre store. Alcohol is a very safe fuel as it disipates quickly and a fire can be put out with water. I used an alcohol stove for many years and was very pleased with it. Some complain about the smell and others about the fact that fuel left in the cannisters tends to evaporate but they work well. Have a good trip.

 

[walmsleyc]

My sources for nearby CNG (2 hour drive!!!) have disappeared. I converted to propane 2 years ago. Cost was less than $1000 (but not by too much). I re-jetted my stove at it works quite well. I have the combine remote solenoid, and propane sniffer module and am happy with that. My little propane take has lasted 2 years now without a refill.

BTW. I now have a spare CNG tank and regulator if anyone is interested.

 

[Benny17441]

I am all in favor of re- jetting a perfectly working stove to keep the cost down on a conversion but be aware that your stove will probably lack the thermocouple switches that are now standart for propane stoves. These switches will automatically shut off the flow of gas should the flame go out and the valve remain open. A little extra care and a propane sniffer would make such conversion safe.

 

[Rick Sylvester]

My 2 cents

I agree with Alan that stowing another tank is easiest and probably cheapest. Whether or not it'll last you 6 months is another story. We're liveaboards and we never got 6 months out of two tanks.

Those non-pressurized alcohol units look pretty nice too. Be careful with putting out an alcohol fire with water though. Since alcohol is water-soluble, burning alcohol will continue to burn until it is diluted enough. A small amount of water would only spread the flames rather than put it out. I think I'd grab a blanket or extinguisher first.

The best answer may have to do with what you plan to do with the boat after the cruise. If you're going to keep it long term and cruise again in the future this might be a great time to do a gas refit.

We did it. $1000 is probably realistic. I don't remember what ours was but that's probably close. I built my own vented boxes that used dead space but we splurged for aluminum tanks. The conversion wasn't difficult but it was tedious.

Our old Seaward stove didn't have thermocouples on the stovetop burners to begin with so we rely on common sense and a hope that we're on the right side of the Darwin curve. Seaward provided a kit with all the parts for the conversion for the stove. They were pretty helpful on the phone.

Hope this helps.