Propane locker through hole

SanDiegoChip · #1 02-28-2011

Hi,
We are proceeding nicely with our build of our propane locker for 2 – 21/2 gal composite propane tanks. We decide to build the locker because we could not find one that works with two 2 ½ gal composite tanks and the others were real costly. Any way my issue is the only space we have to put the locker in our 1978 36 ft sail boat is in the port lazzerett. It also is a bit low. Not real low but I am trying to work out the drain solution. It of course needs to drain out any leaking propane to the outside of the boat. The idea we have been thinking of is a scupper (to keep weight down) coming out the bottom of the locker and then a hose to a through hole with a valve on it for safety above the water line and at a slight downward slant. We do not want water coming into the propane locker when healing over. This may require a long hose towards the stern aft port side for a through hole. The hose would need to be attached to the hull so gear does not put a low spot in it.
To avoid running a long hose to a aft through hole there is a through hole with a flapper in it. This would enable us to run a short hose to the hull next to the propane locker. This would seem to work if it was pointed down as the flapper would hang open as on the side of the port hull low. Then if healing over it would (the flapper) prevent water from getting into the propane locker. It is not the best solution as we would need to check the flapper from time to time. However it is an option or is it is my question.
What size vent is also a question, hose and through hole.
Anyone have any other ideas or sugestions and what would be the issues witht he flapper through hole, if it stays open?

Example:

pdqaltair · #2 02-28-2011

Seems to me the propane is not going to push the flapper open.

Would a vent through the transom make more sense (heeling does not affect the center line)?

Does the box have a lid? Propane is not that heavy. It would not be difficult for the propane to overflow the box and go into the locker or the cockpit. I wonder if this design will be any better than simply storing cylinders in the locker, which you have ruled out.

Unfortunately, I do not believe this is a suitable location and the problems may not be fixable. Is there no place to install a new deck hatch, away from the cockpit?

Stay safe.

mitiempo · #3 02-28-2011

The vent has to be a minimum of 1/2" inside diameter. I would skip the valve and the flapper as the drain has to always be open. The locker, although inside, will need a tight fitting lid as well.

SanDiegoChip · #4 02-28-2011

OK I failed to say it is under construction, the propane locker. We have a lid and a seal for the lid. We are fiber glassing the box now.
There is no other place for the box. It will work if we use a long hose to a through hull located in the aft port side. We are just trying to get away from that.
I figured if the through hull was located in such a place that it was pointed down the flapper would by default stay open. This was I guess another crazy idea I had to run by someone else to see if it was really crazy.

chef2sail · #5 02-28-2011

I am not liking this especially if you a putting this in a lazzarette which actually is inside the hull and there maybe a panel which opens to the engine compartment. Oour lockers are under the port and starboard helm seats which does not empty anywhere into the hull of the boat and is solid fiberglass.

Dave

JohnRPollard · #6 02-28-2011

SDC,

I agree with these guys to skip that flapper. I also share some of their concerns about the location of the locker. In any event, your should 'glass the inside of that locker too, not just the outside. that might require taking it apart and 'glassing the components individually before re-assembling.

Quote:

The idea we have been thinking of is a scupper (to keep weight down) coming out the bottom of the locker and then a hose to a through hole with a valve on it for safety above the water line and at a slight downward slant.

Another thing: In the sentence above, when you say "with a valve on it", are you referring to the flapper? It's not clear to me, but it sounds like you might also be contemplating a seacock-type valve on that through-hull fitting, so that you can close it? If so, it's my understanding that ABYC does not permit a close-able propane locker drain, i.e. no seacock.

Some of these other guys may know the answer to that, but it is something you should clarify before adding a seacock or other close-able valve.

Sometimes, the only way to get "drainage" on all points of sail, is to have two drains.

mitiempo · #7 02-28-2011

There cannot be either a valve or flapper in the vent hose. It must "always be open" which also means it cannot be able to be closed. The outlet of the vent on the hull has to be a minimum of 20" from any other hull opening to the boat's interior.

From ABYC

SanDiegoChip · #8 03-02-2011

Wow this is some great information about the location and the valve on the through hole.
We will not be putting a valve on the propane locker through hole then and will keep it 20 inches away from any other.
Last night I was working on the propane box, glassing the inside. It is getting glassed inside and out and the top will be glassed also, top and bottom. Then it will get a hole curt in the bottom for a vent hose to the through hole. NO flapper or valve.
Thanks for this important information, it is just what I was looking for.
Chip

JohnRPollard · #9 03-02-2011

SDC, Looks like you're doing some nice work there.

When it comes time to run the propane line(s) from the locker to the appliance(s), be sure to use something like this where the line exits the locker: Trident Vapor Tight Fitting. These are really slick and easy to install.

mitiempo · #10 03-02-2011

I agree with John, but try and find an electrical supply house - they cost less. After buying mine from a marine store I was at my electrical supplier one day and found them for $1.25 to $2 each in many sizes. Exactly the same product without the package.