CNG vs. Propane?

[Emmalina]

Had a CNG car in Italy . Very economical but had to get the tanks checked every 2 year. Not mad about 200bar tanks full of gas in my boat ! LPG fills at 8 bar so I now have two nice Composite tanks in my boat that you can buy of any gas supplier in Thailand. If CNG has been around for so long in the US doesn't anybody have to get there bottles certified ?

[Tricolor]

Originally Posted by Emmalina

Had a CNG car in Italy . Very economical but had to get the tanks checked every 2 year. Not mad about 200bar tanks full of gas in my boat ! LPG fills at 8 bar so I now have two nice Composite tanks in my boat that you can buy of any gas supplier in Thailand. If CNG has been around for so long in the US doesn't anybody have to get there bottles certified ?

Very true, some trucks and city busses also drives on CNG. But you don't want to go with a taxi to try to get your CNG boat tank filled.

[Island Time O25]

https://www.corpbrothers.com/ma0502/...ng-dealers.php

Our boat came with 2 CNG cylinders - one larger and one smaller. We go through the larger one about 1 per season. Costs $70-80 to refill locally. Not cheap but worth every penny in terms of safety and peace of mind. For now we do short coastal trips and mostly weekends liveaboard.

With plans to travel further afield I picked up 2 add'l larger tanks from a marine yard sale for $5 each. Considering they are $250 to first buy for subsequent exchanges not a bad deal. 3 large + 1 medium tank should last us at least 1 full cruising year.

No need to re-certify periodically as you just exchange the cylinders at point of sale. If you drive to the company owned exchanges it's about $15-20 cheaper to refill. It costs them that much to transport plus the dealer's cut, etc.

We contemplated converting to LPG but since we are not yet ready to cruise we have pushed that decision down the road, if ever. I am told by several cruisers that in most cities where there are bus/car gas powered fleets one should be able to recharge the cylinders, even if semi-officially. Especially in the poorer regions of the world where one's dollar goes much further then here. Not as easy as the LPG refills but considering safety I'd rather cook over a charcoal Magma grill then on an LPG stove. But that's me.

[Island Time O25]

Originally Posted by Tricolor

Very true, some trucks and city busses also drives on CNG. But you don't want to go with a taxi to try to get your CNG boat tank filled.

Interestingly the launches in our mooring field (as per CG regs?) are not allowed to transport gasoline in any type of containers but are allowed to transport diesel and CNG. Not sure about LPG as I bring the 1lb cylinders for the grill in my sail bag.

PS Most launch passengers usually assume that my CNG cylinder is a scuba tank and I resolved not dissuade them from that thought.

[clockwork orange]

As has already been said LPG is very convenient, at least in the US being available everywhere IF you use standard 20lb steel tanks to exchange but this is not always the case. My old Gemini cat came with horizontal steel tanks which were quite rusty and I changed them out for 11lb composite tanks because 20lb vertical steel tanks would not fit the locker. So, with the composite tanks (or aluminum tanks) I can not just exchange them and have to find somewhere to have them filled. Not a problem when in my home area but when I did a month long trip we needed to fill them twice which was not so easy but at least we were able to. I doubt we could have if it were CNG. Coincidently just this morning as I was leaving my bank I noticed that the gas station next door had a sign saying they fill CNG tanks. I hadn't even thought of CNG in years.


Steve.

[john61ct]

Seems clear to me, *if* usage is low enough *and* CNG refill is available in at least one port visited regularly enough, the inconvenience of occasionally refilling with CNG may well be worth not having to retrofit and ongoing inspections for safe use of propane.