Use of Bilge Blowers

[Sailor_Al]

I was just reading a post about the storage of propane on sailboats and it brought to mind my lack of use of the Bilge Blower.

I do not use it on my diesel sailboat. I'm I making a mistake?

What does our forum forum members do? Do you clear the air after refueling or anytime starting the Diesel engines?

[wingssail]

Originally Posted by Sailor_Al

I was just reading a post about the storage of propane on sailboats and it brought to mind my lack of use of the Bilge Blower.

I do not use it on my diesel sailboat. I'm I making a mistake?

What does our forum forum members do? Do you clear the air after refueling or anytime starting the Diesel engines?

We've felt that diesel is not an explosive risk. We do not use a blower.

Propane is definately an explosive risk however it is contained in a self venting propane locker. We do not put a blower there either. However, if we smell propane (pretty strong smelling stuff) we take a lot of precautions.

Gasolene is not only explosive, but powerful. It is not introduced into the boat.

[dougweibel]

Bilge blowers can serve two purposes - to remove hazardous fumes or to introduce a cooling airflow into the engine compartment. With diesel I have no concern about fumes. I would probably run mine for a half hour before and after shut-down to help cool the engine and engine compartment except they are such energy pigs. They suck almost 15A each.

It would be interesting to hear an engine expert opine on if cooling the engines more quickly after shutdown is a good or bad thing. I'd suspect it is neutral or bad, with a longer cool down being better. It is nice to get any extra heat out of the boat, though, when it is hot outside.

[Sailor_Al]

I keep the outboard gasoline in the anchor locker; it's sealed and drained

I normally keep the Starter battery Off for the engines because the fire suppression system will kill the Start battery. I am considering starting the blower when the Start Battery is turned on.

[osprey877]

Not directly on point perhaps but The marine electric shop that serviced my alternator suggested I run the engine compartment blower to ensure a supply of cool air to the rear of the alternator. Apparently the fan on the front of the alternator draws in air from the rear of the alternator which in a crowded engine compartment can get pretty hot.I don’t have a separate bilge blower so that is not an issue.

[BillKny]

Diesel fuel under normal conditions is not an explosive risk, but it CAN be. A leaking high pressure line in a fuel injection system can make a fine diesel mist that is extremely dangerous.

Aside from that... Diesels LOVE to breath cold air. The colder the air, the more oxygen there is per volume, and the more efficiently the engine can burn its fuel. In addition, everything from batteries to electronics prefer to NOT be overheated. Many (most?) small sailboat engine rooms are VERY poorly ventilated.

Our boat has a push blower AND an exhaust blower than come on whenever the engine or genset are turned on. It makes sense, and really helps. It makes almost no difference at all in the running temperature of the engine, but engine room temperature is a LOT cooler with them running, and that is good for everything.

[VWKDF]

My ignition had a timer relay that prevented starting the engine till the blower had run (I forget for how long). It was a bit of pain on short trips around town. Oh, this was on my 67 Amphicar.

[chasfgr]

Originally Posted by osprey877

Not directly on point perhaps but The marine electric shop that serviced my alternator suggested I run the engine compartment blower to ensure a supply of cool air to the rear of the alternator. Apparently the fan on the front of the alternator draws in air from the rear of the alternator which in a crowded engine compartment can get pretty hot.I don’t have a separate bilge blower so that is not an issue.

My fresh-air inlet, a 50mm diameter pipe, from cockpit to engine compartment, actually ends above the alternator.
I fitted after I had my 3rd alternator burn-out when I first had the boat in 1996-98. Since then (22 years) I've never had to change the alternator.
Incidentally the water pump">raw water pump, driven by the same belt, has stopped developing leaks
Most alternators draw air from back to front, and sparking brushes appear to overheat the whole unit. So making sure those are in good condition is probably the most effective check.

[sail sfbay]

Originally Posted by Sailor_Al

.........lack of use of the Bilge Blower. I do not use it on my diesel sailboat.........What does our forum forum members do?........

My Hunter 46 and powerboat have below deck blower(s) but have never found a need to use it to clear the compartment air after refueling or during diesel engine starting unlike my gasoline engine skiboat, albeit I do operate periodically to test its functionality. Propane is always shutoff at the tank, located in the aft lazarette, and solenoid switch is off when not in use.

[Cadence]

I've oiled on a tug summers, while in school. The butt bucket was a can of diesel fuel. This dumb ass smoked but threw the buts into it as did the guy I relieved.

[Cheechako]

Originally Posted by Sailor_Al

I was just reading a post about the storage of propane on sailboats and it brought to mind my lack of use of the Bilge Blower.

I do not use it on my diesel sailboat. I'm I making a mistake?

What does our forum forum members do? Do you clear the air after refueling or anytime starting the Diesel engines?

I run mine 100% while motoring unless it's a short trip. Less so in cold climate, but in warm areas, a long motoring makes the cabin hot and the heat is still in the engine room next AM.

If your goal is to have it extract fumes, be sure to install properly with a suction hose from the fan to below the engine.

[Scrimshaw4]

I have a large diesel engine and run the blower in the summer when the engine is on and for about 1/2 hr after shutdown to get the heat out of the boat.

[caffel]

Propane use is safer if you use an explosion proof blower that's sourced low in the bilge.
There are any number of leak suseptible tubes and fittings outside of the propane locker.
The safest procedure is to run the blower before any sparking load such as a starter motor and all the time while the propane solenoid is open.

[Mike Banks]

A 15 amp bilge blower is OK while engine is running--I used to use a radiator fan to do it but the simple axial fans that I use mounted in PVC conduits draw very little power. All one needs do is to set them to blow air into the bilges and dark unventilated places on your vessel while extracting air from the aft bilges. Each day they change the air in the vessel once or twice. They can be driven with a small solar panel and rechargeable battery.

[CarinaPDX]

Volvo-Penta requires ventilation, as specified in their installation manual, for their D1 and D2 diesel engines. That is for cooling. It would be a good idea to have an ignition-protected fan if you are using propane, just in case you need to vent some fumes. But ultimately the propane tanks need to be safely vented overboard, the gas line shut off at the tanks when not actually in use, and sniffers need to be installed and working.

I installed a ventilation fan that is very heavy duty. The usual suspects are only rated for a few thousand hours MTBF and are only suitable for the required 5 minutes of ventilation before starting a gas engine, and not for continuous duty. I have added a speed controller so I can get the rate down to a reasonable level, and am considering a thermostatic delayed-off relay.

Greg