CNG to LPG conversion

[LauraJane]

Ahoy!

My Sabre 34 has a CNG tank and stove. I want to change to LPG as CNG is harder to find.
I am OK with replacing the stove instead of retrofitting, but the problem is with the tank changeover.
Its a small compartment and it has been recommended that I mount an LPG tank on a bracket on the stern pulpit. I have been away from the water, but I haven't seen this done before. Anyone have any experience with this?
There are many different size and shape tanks on Defender and Westmarine, so I don't see a compelling reason for an external tank mounting.
Thoughts?
Laura Jane

[rwidman]

Originally Posted by LauraJane

Ahoy!

My Sabre 34 has a CNG tank and stove. I want to change to LPG as CNG is harder to find.
I am OK with replacing the stove instead of retrofitting, but the problem is with the tank changeover.
Its a small compartment and it has been recommended that I mount an LPG tank on a bracket on the stern pulpit. I have been away from the water, but I haven't seen this done before. Anyone have any experience with this?
There are many different size and shape tanks on Defender and Westmarine, so I don't see a compelling reason for an external tank mounting.
Thoughts?
Laura Jane

For safety, that propane tank should be in an approved "propane locker". It needs a shutoff solenoid and a gauge so you can check for leaks. There are several other requirements so you should find the ABYC specifications or find an ABYC certified installer to do the work.

The stove should be approved as well with automatic gas shutoff if the flame goes out. If your stove already has this feature you may be able to keep it and just change the orifices.

[GordMay]

Greetings and welcome aboard the CF, LauraJane.

Does this resemble your CNG locker?
If so, see
➥ http://mjsailing.com/projects/cng-to...gal-gsi-stove/

[LauraJane]

Thanks, GordMay,
The link to the thread on CNG-LPG conversion was very helpful. I am not going to convert the stove, but have a lead on a good used LPG stove. Nice to know that others have sailed this way before me.
LJ

[DeborahLee]

Size does matter. You won't get as many hours out of LPG as you do with NG. Our boat didn't have a gas locker when we purchased it and could not find a place to put one. We had ours put on the stern pulpit. At first we had 2 6lb aluminum bottles but found we were constantly changing them every 6 weeks or less. Now have 2 10lb fiberglass tanks and that almost doubles our capacity. The auto shut off is somewhat exposed back there and gets replaced every couple years. Other than that no problem.

[garyj4101]

Originally Posted by LauraJane

Ahoy!

My Sabre 34 has a CNG tank and stove. I want to change to LPG as CNG is harder to find.
I am OK with replacing the stove instead of retrofitting, but the problem is with the tank changeover.
Its a small compartment and it has been recommended that I mount an LPG tank on a bracket on the stern pulpit. I have been away from the water, but I haven't seen this done before. Anyone have any experience with this?
There are many different size and shape tanks on Defender and Westmarine, so I don't see a compelling reason for an external tank mounting.
Thoughts?
Laura Jane

Number 1, CNG is lighter than air so it can be stored inboard.
Number 2, LPG is heavier than air and in case of a leak the gas will find its way into your bilge. Not a good idea, where there is gas and a spark things have a tendency to go BOOM!!!
Unless your LPG storage space is vented overboard go with the recommended storage on the pulpit.
GaryJ

[sailcrazy]

FWIW-we had an internal LP storage locker...I sealed the deck lid, converted the space to a hanging locker in the Mastersuite (a much better use of the space), and mounted the LP tank on the aft side rail. As someone pointed out, LP is heavier than air, so instead of sinking into the bilge, it now sinks to the water, outside the boat, if we have a leak. We used a painted steel tank for several years, and have now replaced it with a F/G tank. All in all, a good conversion!