Propane Storage on Rail

[RonRelyea]

I'm considering getting a 17 pound fiberglass composite tank for my boat. I have no propane locker so, I am considering some sort of method to hang it from the rail. I do not need it hooked up when stored.

There are Polyform fender holders that will accommodate a 12" fender and the propane tank is 12" in diameter. Has anyone ever used a fender holder for this purpose? Will it hold the 27 pound filled tank or are the holders too fragile?

Does anyone else have a good solution?

 

[Stu Jackson]

Could be questionable. Good application for a starboard holder like this one. Make sure you seal all penetrations.

 

[WayneH]

This picture is not from my boat. But it shows the top of a rail mounted propane tank and it's wooden support. The support had a shelf on the bottom and angle pieces to hold the shelf and side screwed together.

I took this picture because my unit does not have the curved support piece to prevent the tank from rolling thwartships and I wanted to remind myself to add this support.

 

[Ken Cross]

It seems like a good idea if it's stout enough. Aesthetically a canvass cover would add little weight. Doggoneit now you got me thinking.

 

[Stu Jackson]

WAIT.

How can a holder that's designed to contain what is essentially a basketball be strong enough to hold a metal cannister of propane???

Man, I'd think twice.

UIf it was such a good idea, I think we'd have seen it employed all over the place.

I haven't seen one in 40 years of boating.

 

[RonRelyea]

Polyform's reply

I eMailed Polyform, the maker of the fender holders ... they DO NOT recommend using their fender holders for this purpose. (Thank you Tom Case of Polyform for replying in 3.5 hours - nice customer service!)

I am going to go with Stu's recommendation of building a box out of starboard. I will post pictures as soon as I do it - after installing a new exhaust elbow, building a shelf for 2 more egc batteries, installing a new hevay duty alternator (thanks MaineSail) , install new autopilot and radar ... well, maybe next year!

 

[Captn Scotty]

I built a propane holder out of a split piece of polycarbonate pipe that clamps on my stern rail. It spreads open when I push the cylinder in and hold it very secure when in rough seas. I'd send you a picture, but I'm at sea for another week!

 

[Apper]

Any such container should be vented from the bottom to well below the gunwale and away from any drain or exhaust openings into the boat. Propane and CNG are both heavier than air.

 

[RonRelyea]

The relative density of propane gas when compared to air is 1.56. Propane gas is, therefore, heavier than air.
Natural gas (CNG) is lighter than air. The relative density when compared to air is 0.63. Consequently, natural gas will always rise when there is a leak.

 

[Apper]

RonRelyea is correct that natural gas is lighter than air and will vent upwards while propane is heavier than air and should be stored in a properly vented locker to prevent leaking gas from collecting in the low areas of a boat.

 

[markwbird]

I think it is good idea. I am glad you thought of it because I am considering the same thing. Stu makes a good point in that it is worth a looking over to make sure that it will support the weight. It probably will. A fender is very light but that does not necessarily mean it will not hold more than that. I looked at some of those photos of the homemade wooden box holders. No.

 

[RonRelyea]

I ended up getting a device that is used to mount an Igloo water cooler to a truck. I mounted that on my aft rail with stainless hose clamps. Not the prettiest, but it made it from upstate NY to FL

 

[Captn Scotty]

Here are some pictures of the pipe one that I built. I got the idea from dive bottle holders and works extremely well. I'm sure someone could make something more aesthetically pleasing than mine with little effort.

 

[Apper]

If you use the small propane cylinders such as those made by Coleman then here is a simple propane locker you can make for less than $20.00. This locker will store 3 partially full, full or empty propane cylinders. You need 1 30" to 32" length of 4" white PVC tubing (4" id), 1-4" x 1 1/2" fitting with 1 1/4" x 3/4" hose connection, 18" of 3/4" id tubing, 1- SS screw clamp for tubing, 1 - 4" socket x 4" threaded fitting, 1 - 4" threaded plug, 1 - PVC solvent cement, long nylon quick ties or long SS screw clamps. For this application primer for the PVC should not be required. To mount the completed storage container fasten to a stanchion in the rear cockpit by large nylon ties or multiple screw clamps and hang the tubing over the stern below the gunwale.

 

[LeslieTroyer]

From the PO I have mine on the stern in a fender holder - looks ugly and doesn't feel secure. I plan on spending the $$ for two mounts and relocate everything to the anchor locker. Even with two sets of chain and rode I have enough space for two 6lb canisters. I've seen lots of folks with them on the stern rail, I'm not sure that meets the requirement of off board venting, a slight wind over the stern and a leak could get in thru a lazzerett or ???

 

[markwbird]

Yes, the stern rail meets the venting requirements. I am not sure putting them in the anchor locker does. Is it compartmentalized and vented overboard? I would be concerned that the tanks could be damaged by chain. One of the rules of propane installation is that you cannot have anything else in the compartment with the tanks.