Bilge Blower Technique

[higgs]

When I had a gas engine I would run my bilge blower during fueling. As best as I can remember, this was what I was taught to do. Made sense to me.

I am now preparing to teach a Power Squadron course and they say to turn it off during fueling.

It seems to me tht if a bilge blower running has the potential to ignite funmes, then it is not very satisfactory as a blige blower.

I am interested I your thoughts on this.

 

[Ross]

I always heard to run it for 5 minutes after fueling before turning the key. Never heard or read any concerns about running it all of the time.

 

[Peggie Hall HeadMistress]

Run blowers only AFTER fueling, never during

Before fueling, all hatches should be closed and all electric/electronic devices off. Run blower(s) for at least 4 minutes after fueling, then open engine hatch and sniff before starting engine.

So why not during fueling? It's not because the blowers could spark...it's because blowers pull in air via the passive ventilation louvres...and there a lot of gas fumes present outside the boat during fueling...so if you run the blowers WHILE fueling, they can pull gas fumes into the engine room....which would make running the blowers kinda pointless.

Btw...I owned gas engine boats all my life was a CG Aux member for several years.

 

[sailingdog]

I'd second turning the bilge blowers off when fueling. If someone has spilled gasoline on the water near the fuel dock, you could suck in a fair amount of vaporized gasoline... and that would be bad. You want to minimize any chances of getting gasoline vapors inside the boat. So close all hatches, ports, the companionway and sliding hatch, if possible before fueling. The Bilge Blower should be connected to a switch reachable from outside the boat through the open companionway.

One point... if you're at the fuel dock for more than a few minutes and someone has spilled fuel there, there is a small chance that you won't be able to smell gasoline fumes below on your boat, since your sensitivity to it drops after a while due to all the nasal receptors being taken up. If you have an in-board gasoline powered engine, having a fume detector aboard is a good thing.

 

[Ross]

The point concerning gasoline vapors in the marina are most valid. Several of the boats in our marina are gasoline fuel power boats and the owners refuel them from cans. When the wind is right I can smell the gasoline being poured two piers up wind from me.

 

[higgs]

Thank you Peggy, it makes sense to me now.

 

[Paul Mermelstein]

Before fueling, all hatches should be closed and all electric/electronic devices off. Run blower(s) for at least 4 minutes after fueling, then open engine hatch and sniff before starting engine.

So why not during fueling? It's not because the blowers could spark...it's because blowers pull in air via the passive ventilation louvres...and there a lot of gas fumes present outside the boat during fueling...so if you run the blowers WHILE fueling, they can pull gas fumes into the engine room....which would make running the blowers kinda pointless.

Btw...I owned gas engine boats all my life was a CG Aux member for several years.

I am an instructor with the Power Squadrons. Peggy has it right. One more thing to add: gas fumes are heavier than air, and will settle in the low spots of the boat, so if you don't smell it, it does not mean the fumes are not there. Hence, the need to keep hatches closed, then run the blower.

 

[Stu Jackson]

We have a diesel engine

and have never used the blower. Reasoning: I want to be able to smell any fumes that may be in the boat. The blower is a "leftover" from the old gas engine days on the Catalina cockpit engine control panel. Everything electrical should be off when fueling, including the 1-2-B switch (or whatever switch arrangement you may have). In our weather here most of the time the entire boat is opened up anyway, so we have good ventilation all the time. Pull up to fuel dock, turn off engine panel, fuel, sniff, check bilge, sniff some more, check expected fueling amount to actual fuel delivered (gee, if I put in 2,000 gallons when I was expecting only 12, then something's wrong big time), record readings in engine/fuel log, check around some more, and only then get going.