How important is a blower?

artistofdesign

Yeah,
 I've heard all the stories about someones engine blowing up due to fumes in the engine compartment. but it sounds to me... it's out of stupidity by not being careful and opening up the engine cover before starting the motor. A simple precaution right?
I bought my (212 Rinker, carbed 350 mag) used and for some reason the blower was removed...but the hose was till there.
 What other advantages does a blower provide?
and no.. it's not a personal problem... get your mind out of the gutter!  really, I'm being seriousness here

Black_Diamond

@Artist:  Gasoline fumes are heavier than air, so they sink to the lowest point, so just opening the engine hatch does nothing except let you smell and look around.  You should be EXTREMELY concerned about not having/using a blower.  It is the only think to keep fresh air moving through the engine compartment before start up and below cruise speeds.  The intakes to the blower should be ideally at the lowest point in the bilge area.

Do a google search..it's not 'stories' you'll read, and it's not the engine blowing up, the whole engine compartment explodes.  Usually with very bad results for those in/on the boat.

Black_Diamond

http://www.boats.com/reeds/jsp/rn_ch_2_a.jsp  See the ventilation section

http://www.uscgboating.org/regulations/boatbuilder_s_handbook/vent_partc.aspx

FYI: you would fail a boat safety inspection and at least here in the USA, the CG or marine sheriff would find your boat a 'towback' if they checked you on the water (ie: not suitable for operation).  Plus a nice handy-dandy fine.

 

Do yourself, your crew and anyone around you a favor and buy a blower(s) and use it, they are ~$30.

 

artistofdesign

@ Black Diamond

I didn't know this.

Thanks for the informed explanation. Woo! such a cheap preventative investment. 

Hmmm... so which brand do most boaters use?

Black_Diamond

If you look at www.westmarine.com and search 'blowers' you'll see the selection.  depending on your hose diameter, you can pick your type.  Only a few brands.

raybo3

You should add the blower, like yesterday. 

Babyboomer

http://www.boatus.com/boattech/articles/bilge-blowers.asp

TikiHut2

BD is absolutely right about fumes down low. Our blower "exhaust" hose inlet is tie wrapped about 6" from the bottom of the bilge with 3 other "intake"(bilge fresh air intakes). Our engine starting drill ALWAYS begins with the blower running, immediately followed by actually taking a whiff at the vent for unwanted fumes well before turning the key. It's often just left on whether we are idling around or even running at cruising speed. I'll say that's because we're safe and partially because of early onset forgetfulness.

Here's a YouTube video of a firefighter who purposefully ignited a boat for an exercise but underestimated the fumes laying in a poorly vented bilge. I think of it every time I hit the key. Mike

BOAT EXPLOSION YouTube LINK

TonyWalker

From my old days as an amateur pilot, I have a check list for startup.  The things that are on it are the things I have missed/forgot to do.  Switching on the blower(s) is on the list.  Since there are two in my case, I feel for air coming out of the exhaust ports and also give this air a sniff.  If I did not do this, I would have missed the fact that they do fail.  So far I have had one go bad on two occasions.

I have mentioned this other thing a couple of times before but I will do a repeat anyway.

The blower is also good for keeping humidity out of the engine space while at the dock or on the hook.  I frequently keep mine running just for that purpose.

Tony

Salt Shaker 342

artistofdesign

Thanks Guys!

@tikihut2....Wow! That's a shocking reminder of just how explosive fumes are.

Fumes are way more explosive than gas in a can, because its mixed with air.

I remember being by the burn barrel (burned trash outside my house) and I doused the barrel with gas to get it started. I till had the (open hosed) five gallon gas can next to me when I went to ignite the burn barrel, bent low and Whooof! the burn barrel went up.. but the gas can did not. Luckily I moved it out of the way quickly.

But thinking back, I wondered why the gas can did not ignite like the burn barrel did, and I concluded that it was because of the absence of air.

 Anyway, yeah I bought a bilge blower!

melvyn

Black_Diamond said:

@Artist:  Gasoline fumes are heavier than air, so they sink to the lowest point, so just opening the engine hatch does nothing except let you smell and look around.  You should be EXTREMELY concerned about not having/using a blower.  It is the only think to keep fresh air moving through the engine compartment before start up and below cruise speeds.  The intakes to the blower should be ideally at the lowest point in the bilge area.

Do a google search..it's not 'stories' you'll read, and it's not the engine blowing up, the whole engine compartment explodes.  Usually with very bad results for those in/on the boat.

melvyn

do you need to use the blower with a diesel engine black diamond

Black_Diamond

@melvyn: nope, no fumes to ignite from diesel. Some have blowers just to help pull in fresh air on big engines, BIG engines.

mvn

Kind of related.....I found that the blower suction hose that runs from the blower to the bottom of the bilge was almost collapsed due to the type of hose (dryer vent type) and the installation technique.  When going over a step, that style of hose tends to flatten causing a HUGE restriction.  I found a high temperature hose that acts like a "bendi-straw" in that it can hold its shape when curved.  I was able to form an S-shape that went from the blower, over the step, under the engine and lays parallel to the bottom of the bilge.  I replaced the blower discharge hose with a high-temperature urethane wire-reinforced hose.  I get way more flow now.

Mark

PS.  This spring the blower started making a **** of a noise.  Turns out, it has so much suction it inhaled a cap-plug that must have been in the bottom of the bilge.  It was covered in gel-coat so it must have been used during the manufacturing process.