Gas can safety

B

bob Petritsch

Active member
ive always used a small outboard motor with a self contained gas tank. I’ve now purchased an 8 hp engine and it has a remote tank. I am concerned with putting a gas tank under the deck on my fiberglass Higbee sneakbox.
Do I have to worry about gas vapor accumulating belowdecks? I would not want to keep the gas tank on the top deck. Any safety hints would be appreciated.
 
bob Petritsch said:
ive always used a small outboard motor with a self contained gas tank. I’ve now purchased an 8 hp engine and it has a remote tank. I am concerned with putting a gas tank under the deck on my fiberglass Higbee sneakbox.
Do I have to worry about gas vapor accumulating belowdecks? I would not want to keep the gas tank on the top deck. Any safety hints would be appreciated.
Click to expand...

My first response would be to consult the CG regs on venting a fuel storage location. Those regs are written with your safety in mind.

Also a couple questions; Is the tank "new"? Is it presently free from seepage and leaks? Even a little bit of seepage can and will create major fumes. As long as those fumes are not allowed to collect in a closed space, you should be OK. The best ventilation allows for a flow of air thru the compartment. Even tho the front deck may be wide open on one end, it may not have good air flow. One could always add one or more clam shell vents to increase and promote a positive air flow. These can be purchased in various sizes and are commonly used to vent the engine compartment on boats with an inboard engine.


View attachment clamshell vent.jpg
 
Is the compartment sealed? I never worried about fumes with a tank under a deck if it was open to the cockpit, and you would need an ignition source close by which you don't really have with an outboard.
If its sealed, then you may have fumes collect, but still no ignition source. I believe the Coast guard requires a sealed space be ventilated, and you must carry a fire extinguisher. So ventilating may be enough. If your real concerned, you could install a permanent tank with outside fill and overflow, but you lose all portability.

But what do I know, I did dangerous stuff all the time, lol.
 
gcs said:
Is the compartment sealed? I never worried about fumes with a tank under a deck if it was open to the cockpit, and you would need an ignition source close by which you don't really have with an outboard.
If its sealed, then you may have fumes collect, but still no ignition source. .
Click to expand...

A spark from static electricity has been know to start more than one gasoline fuel fire. Hard to prevent all sources of ignition. Easier to prevent a build up of flammable fumes in the first place.
 
All portable gas tanks are made to vent. If were not, it would create a vacuum from the fuel pump sucking fuel. I have never had a lot of vapors. Did have a one gallon spare fuel can that I sealed Really well, looked like a two gallon can after sitting in the sun.
Cans under the deck should not have any problem.
 
Capt Rich Geminski said:
All portable gas tanks are made to vent. If were not, it would create a vacuum from the fuel pump sucking fuel. I have never had a lot of vapors. Did have a one gallon spare fuel can that I sealed Really well, looked like a two gallon can after sitting in the sun.
Cans under the deck should not have any problem.
Click to expand...

Newer tanks, for many years now, have been designed with a one way only vent. The vent is designed to let air in, but not let vapors out. Yes with a rising temperature, there will be a resulting pressure increase inside the tank. It is quite common around here to leave home at 30 degrees or less and by mid morning be up to 45 or 50 degrees.

Maintaining the entire fuel system in good condition is critical to preventing fires. The complimentary approach is to promote good air flow to disperse any possible fuel fumes.
 
Dave, used to be a yard sale junkie. Still have metal gas cans from years ago, some like new. Hate to buy at marine supply stores, cleats, oar locks and other hardware are my downfall. Found a 50# box of brass and bronze hardware [screws, bolts, nuts etc] for my estuary project.
 
To Dave's point on air flow, barometric and relative humidity issues can cause negative pressure with only a top vent, not allowing vapors to rise. A bottom vent will help.

Ran a construction company and we studied a case of CO2 poisoning in a warehouse with good airflow. A combination of factors caused a "no drift" area around the work being performed. 2 OH doors, 20' ceilings, etc.

When ventilating you're managing an atmosphere interchange between ambient and your control.
 
Two points:

1) I wouldn't worry too much about vapors exploding. Motor is outside the deck, gas can is in. However, it's not a 360 degree sealed deck like a lot of I/O or inboard gas boats.

2) The tank will vent just fine.
 
You must log in or register to reply here.
Back
Top