First boat <img src="pic.gif" border=0 alt="*PIC*">

[Guest Frank Hagan, Weekender, O]

Ray, good advice. My "real job" is as a service manager for a manufacturer of gas fired appliances, so its good to see some common-sense warnings about propane. We make propane boilers, and I've got to tell you, I was never so nervous in my life as when I first started with this company and assisted a service technician ... he got down on the floor, reached back, and lit the pilot with his lighter. On a 5,000,000 BTU/hr propane boiler. Wow! He now uses a click start ignitor (or he better be!)

Anyway, just a bit of clarification:

:

: Propane tanks are designed so that if pressures

: inside the tank build up too much, they will

: vent outside the tank. This could mean in

: your garage or house. Definitely a real

: bummer if this happens to you with a flame

: source present.

A bummer even if no flame source is present. Propane gas settles, as you noted later, and doesn't dissapate into the air. So if the tank vents when you aren't around, and come back much later, it could be pooled around your feet when you go to light it. Natural gas is lighter than air, so it tends to rise and mix with the air. So you don't have pockets of it that can ignite. But you do with propane.

:

: Propane is stored as a liquid in the tank under

: pressure. As gas is used, pressure is

: reduced and the liquid evaporates into a gas

: to maintain constant pressure. If the tank

: was cold and then warms up pressure could

: build faster than the gas was used and vent

: to outside the tank.

Pretty close to my understanding. Propane becomes a gas when it is warmed up. The amount of available gas is a function of the amount of liquid propane in the tank and the temperature on the side wall of the tank. So as it warms in the room, the pressure might build in the tank. In a properly maintained tank, you could never have the gas suddenly build pressure due to warming up a room, unless the room was on fire or something. But you are right that the tank could vent to the room for other reasons. Most of the time it isn't the tank at fault, but a hose that is compromised because of fat drippings (on a barbeque) or sunlight degradation.

:

: When used on boats, propane is always stored in

: a very expensive propane locker that is

: airtight, with a hole in the bottom of the

: tank with a hose attached and vented

: overboard. Propane gas is heavier than air

: and sinks.

Propane lockers are sealed off from cabins and cockpits, with holes through the hull so the gas can escape overboard. Sometimes they are stored in racks above the deck. They often have loose fitting hatches over them when they are in lockers. Small bottles for your rail-mounted barbeque are often stored in bags hanging over the side of the boat. Think of the stuff as explosive water, which will pour out. You don't want that pouring below into a cabin or bilge, or into your cockpit. But overboard is fine.

:

: Never bring a propane tank into a closed in

: area.

A drafty garage is probably OK. The main problem with propane heaters is that they produce a lot of colorless, odorless carbon monoxide (CO) gas. More people are killed or injured by CO than burned by propane gas each year ... about 200. I talk to survivors sometime, and its not the most pleasant thing I do.

Newer propane heaters have an "oxygen depletion sensor" that shuts off the gas flow when oxygen is depleted ... they rely on the LACK of oxygen rather than the presence of CO to trigger the safety. I personally don't like that approach, and recommend using a CO detector from Walmart. They are accurate, fairly inexpensive, and work like a champ. If your shop is a stand-alone shop, you could plug it in semi-permanently. If you share your boatshop with the wife's car, remember to bring it indoors with you. If she warms up the car in the morning, it will trip the CO detector.

Jake's method also works, keep air flowing in the room to take the CO with it. CO is just slightly lighter than air, so it will move with the air currents. If you install a CO detector, install it close to where you normally work.

Wow, really long winded! Sorry about that guys. Maybe we should add something to the FAQ on shop heating.

fshagan@ev1.net

[Guest Mike - Oregon]

That sounds bad on glass work or paint. Propane heater with a long hose to the outside tank sounds like the ticket - or wait for spring to glass and paint.

Which really sounds good to a guy with no experience glassing a boat and is prone to put it off anyway. Plenty of other thing to tinker on.

Thanks for all the great input!

[Guest J Metzner - Fairbanks, AK]

One small trivia item. Propane will not turn to gas when it's colder than -44F. We had a difficult time cooking the Thanksgiving turkey a few years ago. I had to run a drop light outside to keep the tank warm enough to keep the gas flowing to the stove. It took me a little while to figure that one out.

--John M.

woodchuck@gci.net

[Guest Ray Frechette jr]

There were nights last winter when the 20 lb tank was too small for the ambient outdoor temperature to keep up with the 50,000 btu output of my heater.

The flame would go out on occasion.

a 30 lb tank would have worked better, however the 20 lb was only a minor inconvenience on some nights.

refent@prodigy.net

[Guest Frank Hagan, Weekender, O]

They actually make a device that uses a pilot light to vaporize the propane ... it feeds off the vapor to keep the pilot lit, so there must be a "start sequence" somehow ... so propane can be used in really cold areas (and so you can use a smaller tank). Liquid propane is pulled out of the tank into a small chamber, with the pilot light below the small chamber. If you get many -47 nights, it might be something you'd want to try. Either that, or moving someplace warm!

fshagan@ev1.net

[Guest Frank Hagan, Weekender, O]

It also helps to have more propane in the tank. The lightbulb hanging next to the tank is a good trick ... safe enough so that if the propane vents, it won't burn, but warm enough to help heat up the tank and create more vapor.

fshagan@ev1.net

[Guest Frank Hagan, Weekender, O]

Hey, having Tom compliment someone on his shop is something! Tom's pictures showed the most organized, cleanest shop I've ever seen. I figure yours must be clean enough to eat off the floor.

In case you're wondering where the mess has gone to, I think its in my shop ...

fshagan@ev1.net

[Guest Ray Frechette jr]

I noticed the 20 lb tank having trouble keeping up with 50,000 btu load at about 12 below 0 F.

Thankfully we don't get too many of those up here.

usually no more than 2-3 weeks worth per winter of 10 below or worse. Rarely below 20 below here, close enough to the ocean that it helps keep us warmer than we might otherwise get.

Inland a bit more, and 30 and 40 below is not unusual though.

refent@prodigy.net

[Guest Arnie Eaton]

It's been awhile since Tom saw my shop. It's a big mess now and I need to take time to clean it up. Hunting season starts this Sunday so that will slow things down some. Hope to get a cow elk permit tomorrow, some left over from the drawings.The State Game Dept had 10 left at 5 min. before 5PM. They close at 5. Open at 8 tomorrow and I'll be at their door.

aeeaton@cybernet1.com

[Guest Frank Hagan, Weekender, O]

Elk are limited that much? Maybe I'm thinking of a different animal, but I remember seeing so many of them near Jackson Hole that thinning the herd would not be a bad thing (they feed them during the winter I guess, so the population is larger than it otherwise would be).

My brother is off for his annual "ghost of the forest" search (he calls it "deer hunting," but I call it "taking his gun for a walk in the woods.") Of course, if he actually bags a "one fork or better" buck (the requirement in California), then I'll stop teasing him and join in the meal.

fshagan@ev1.net

[Guest P Doug (WA)]

Thanks guys for all the info. That is what I like about this form, you ask someone a simple question and you gain a whole lot of knowledge. I hope to join you all within a year in the boat building. I have the plans just need to save up the money for the wood. In the mean time I am building the little items, got the ship wheel almost done.

Thanks again

pp.doug@att.net

[Guest J Metzner - Fairbanks, AK]

No worries any more about propane flowing when it gets chilly....we moved. The only propane I use is for the BBQ. I don't do much on the grill in the -40's. It's ok -20 or even the -30's, but -40's is a bit brisk and -50's is hunker-down time. You do go out unless you reeeeealy have to.

I've thought about moving someplace warm. Eventually we will. Someplace where we can get more use out of the Weekender (and justify building an f-boat)

--John M.

woodchuck@gci.net

[Guest capt jake]

ONLY occurs with organic based produsts! I.E. Watco, Danish oils, Lindseed oil, some tung oils.

Spontanious combustion WILL NOT occur with petroleum based prodects.

A lot of folk lore out there on htis. i know the results of this first hand!

jwentz4@attbi.com

[Guest capt jake]

Propane is stored as a liquid in the tank under pressure. As gas is used, pressure is reduced and the liquid evaporates into a gas to maintain constant pressure. If the tank was cold and then warms up pressure could build faster than the gas was used and vent to outside the tank.

True, though this is the reason for the recent requirement for all propane cylinders to be equiped with an OPD (overfill protection device).

I can't remeber teh last time I was called out for a venting cylinder. the only times I have been, was due to being overfilled.

jwentz4@attbi.com

[Guest Ray Frechette jr]

Amerigas still reccomends Never storing or using a propane tank indoors. Even with the new OPD.

The vent is controlled by a mechanical valve. This valve can fail. The spring can get week and vent at lower pressures than rated for.

Also, propane should never be stored, used, or transported in any position other than upright.

refent@prodigy.net

[Guest Phil Davis (TX)]

John,

Like I said before..... Brrrrrrrrrr

Today's high is dog gone COLD..... 59!

Phil

phil@coolbluedesigns.com

[Guest capt jake]

True, true and true agian. I bend the 'rules' a bit.

If transported on it's side, just set it upright for 15-20 minutes before use.

You are right, never 'store' propane inside. I don't qualify my shop as 'inside'. It is isolated from any sources of ignition (furnace and HW heater).

Only me, but practical experience.

jwentz4@attbi.com

[Guest Ray Frechette jr]

The big concern with transport or use on side is that the opening for the gas to come out is now under liquid propane.

If the tank vents from whatever reason, the tank will expell liquid propane as opposed to gas.

If you remember highschool science, a liquid will take up far less room than a gas. Hence, when the liquid propane spills to the ground and no longer has gas pressure to keep it a liquid it will convert to a huge volume of gas very quickly.

OUCH.

refent@prodigy.net

[Guest Ray Frechette jr]

You are right, never 'store' propane inside. I don't qualify my shop as 'inside'. It is isolated from any sources of ignition (furnace and HW heater).

Is your shop wired with elecricity? Power tools can arc on the brushes and be an ignition source.

Even cordless tools.

Keep 9 volt batteries away from steel wool too.

Local church burned down when it was undergoing renovations because when orkes left for the day and closed the door, vibration caused a 9 volt battery to fall off a shelf and into some steel wool.

refent@prodigy.net

[Guest J Metzner - Fairbanks, AK]

Phil,

That's +59 right

When we first moved to Fairbanks, June '92, I noticed something odd about some of the bank time and temperature signs. I couldn't quite figure it out a first, but it dawned on me after a week or so. They were displaying +65F and such. I had never lived in a place before where there was any confusion about WHICH 65 degrees you were talking about when you said 65 degrees. I realized then that, nope you've moved to a different kind of place.

-- John M.

woodchuck@gci.net