On Tue, Dec 29, 2015 at 6:50 PM, Ahmet <[email protected]> wrote: > Well, it is a combination. A good example here: > The C&C 25 has an aft compartment under the tiller, where the gas tank > sits. It is practically on the cockpit, and any fumes just drain out from a > little drain hole. > Now some industrious owners (like a previous owner of "Tabasco") decided > to open up that area and have more space in the cockpit. Which is > wonderful, but now, the fule tank is in a lazarette locker, hence any fumes > or fuel leaks from an expansion, will leak into the bilge. > So I am paranoid, and open up and smell the lazarettes every time. When I > get a chance, I will rebuild a new fuel tank compartment in the aft section > of the cockpit. > So dinghy fuel tanks, propane or what not are very safe as long as there > is room for the accidentally escaped gas to get away from the inside of the > boat. > I once had a bad junction in my propane tank. 10 lbs of propane leaked > within a day out thtough the went hole into the the ocean/air, and nobody > was ever in danger. > Ahmet > S/V Waterdancer Irwin 43 CC > Tabasco (C&C 25) > > > *(just for kicks .. previous boats:)Tapalonong 1995 Whaler Dountless 13 * > > > *S/V Nomad 1984 Catalina 36S/V Harmony 1972 Bristol 26Second Wind 1987 Sea > Ray 30 Sundancer* > *Kismet 2002 MacGregor 26X* > > > > On Tue, Dec 29, 2015 at 5:09 PM, jtsails via CnC-List < > [email protected]> wrote: > >> since no one else has brought it up.... what about all the other things >> we have on our boats that potentially dangerous. Like the gas tank for the >> dinghy, the propane for the stove, the odd can of mineral spirits or the >> admirals hairspray? We are surrounded by everyday things that could go >> boom! Every boat needs a blower that is properly installed and used! >> James >> Delaney >> C&C 38 Mk11 >> Oriental, NC >> >> *From:* Della Barba, Joe via CnC-List <[email protected]> >> *Sent:* Tuesday, December 29, 2015 2:11 PM >> *To:* mailto:[email protected] <[email protected]> >> *Cc:* Della Barba, Joe <[email protected]> >> *Subject:* Re: Stus-List Proper Blower Installation - 30 mki NOWFUEL >> CHARACTERISTICS >> >> >> The typical diesel fire scenario is a high pressure fuel leak spraying on >> a red hot exhaust or turbo component. >> >> >> >> Joe >> >> Coquina >> >> >> >> >> >> *From:* CnC-List [mailto:[email protected]] *On Behalf Of *dwight >> veinot via CnC-List >> *Sent:* Tuesday, December 29, 2015 1:12 PM >> *To:* [email protected] >> *Cc:* dwight veinot >> *Subject:* Re: Stus-List Proper Blower Installation - 30 mki NOW FUEL >> CHARACTERISTICS >> >> >> >> Rick >> >> Nothing about that sounds like a geek to me, just some very good >> information based on sound knowledge, especially this part: >> >> Lots of smell – which may make a blower to ventilate the engine spaces >> very desirable >> >> >> Dwight Veinot >> >> C&C 35 MKII, *Alianna* >> >> Head of St. Margaret's Bay, NS >> >> [email protected] >> >> >> >> >> >> On Tue, Dec 29, 2015 at 1:56 PM, Rick Brass via CnC-List < >> [email protected]> wrote: >> >> The geek in me just has to jump in here with some technical information. >> So here goes: >> >> >> >> Yes, Rick, vaporized diesel will blow up like vaporized gasoline. >> >> >> >> And Yes, Patrick, diesel does not vaporize easily. And is a lot less >> likely to support a flame than Gasoline as well. >> >> >> >> The flash point (lowest temperature at which a liquid starts to >> evaporate) of Gasoline is -45 to -50 degrees F (-60 C, I think). The flash >> point of #2 diesel is 126 F (52 C). Biodiesel, BTW, is about 225 F so if >> you use B10 or B15 in your boat the flash point of the fuel would be higher. >> >> >> >> The ignition concentration of a fuel vapor is the percent of fuel vs air >> that will support ignition. Too low a concentration or too high a >> concentration and you get no fire. That is why (if you are very lucky and >> not too bright, you can throw a lit match into a bowl of gasoline and >> nothing happens. For gasoline the range is 1.4% to 7.6%. Diesel is pretty >> similar at 0.6% to 7.5%. >> >> >> >> The ignition point (temperature at which it will start burning) of gas >> and diesel are also very similar. Gas is 475 F, and diesel is 494 F. >> >> >> >> But gasoline is much more volatile, and at much lower temperatures. So >> you are likely to find gasoline vapor vs. diesel vapor. Any fuel leak at >> above -45 F will result in gasoline vapor. A diesel leak will just make a >> puddle unless the temperature is above 126 F. Yes, it would be a smelly >> puddle, but your nose can sense vapor concentrations far below the >> concentration that would support ignition. >> >> >> >> Since the density of the gasoline vapor is about 2.0 (air is by >> definition 1.0) at standard temperature and pressure (70 F and sea level), >> the combustible vapor sinks to the bottom of your bilge. Diesel vapor would >> do the same thing, except a measurable concentration of diesel vapor could >> not exist at STP. Even high pressure diesel forced out of a pinhole leak in >> one of your injector lines is more likely to result in a smelly mist (too >> high a concentration to support ignition) than in a combustible fuel vapor. >> >> >> >> The flash point indicates when a liquid starts to evaporate. But there is >> another specification called the fire point that is probably a better >> illustration of the relative risk from gasoline vs. diesel. The fire point >> is the temperature at which a liquid fuel will generate a vapor >> concentration high enough to support a flame for 5 seconds – which is >> enough time to cause significant evaporation of the liquid and start a >> real fire (as opposed to a momentary flash). Liquid gasoline has a fire >> point of 30 F (-1 C), while liquid diesel is 154 F (68 C). >> >> >> >> So unless you are boating in some really ridiculous heat, you are >> unlikely to get a fire from diesel fuel. Lots of smell – which may make a >> blower to ventilate the engine spaces very desirable – but a fire is not a >> high probablility event. >> >> >> >> Rick Brass >> >> Washington, NC >> >> >> >> >> >> >> >> >> >> *From:* CnC-List [mailto:[email protected]] *On Behalf Of >> *Patrick >> Davin via CnC-List >> *Sent:* Monday, December 28, 2015 10:43 AM >> *To:* [email protected] >> *Cc:* Patrick Davin <[email protected]> >> *Subject:* Re: Stus-List Proper Blower Installation - 30 mki >> >> >> >> Diesel doesn't vaporize easily, unlike gasoline. That's one of its big >> advantages on boats, that it's non-volatile. It's good practice to shut >> down the engine at the fuel dock anyway, but they're probably asking that >> more as a general policy due to the gasoline boats they fill (or in case >> some gasoline vapors wafted over to your boat). >> >> >> >> The flash point (vaporization temp) of diesel is 126 F: >> >> https://en.wikipedia.org/wiki/Flash_point#Examples >> >> >> >> There's a good writeup on engine blowers here: >> http://www.unitedmarine.net/blog/index.php/2013/01/30/who-needs-engine-room-blowers/ >> >> >> >> On Mon, Dec 28, 2015 at 6:09 AM, <[email protected]> wrote: >> >> ---------- Forwarded message ---------- >> From: Rick Rohwer <[email protected]> >> To: [email protected] >> Cc: >> Date: Sun, 27 Dec 2015 22:16:22 -0800 >> Subject: Re: Stus-List Proper Blower Installation - 30 mki >> >> I am pretty sure vaporized diesel will blow up like gasoline vapor. I >> know vaporized cooking fat will. Don’t most of the fuel docks ask you to >> shut down the engine and run the fan while fueling? >> >> >> >> I had never thought of it as an air supply for the engine. >> >> >> >> Rick >> >> Paikea 37+ >> >> Poulsbo, WA >> >> >> >> >> _______________________________________________ >> >> Email address: >> [email protected] >> To change your list preferences, including unsubscribing -- go to the >> bottom of page at: >> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >> >> >> >> ------------------------------ >> _______________________________________________ >> >> Email address: >> [email protected] >> To change your list preferences, including unsubscribing -- go to the >> bottom of page at: >> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >> >> >> _______________________________________________ >> >> Email address: >> [email protected] >> To change your list preferences, including unsubscribing -- go to the >> bottom of page at: >> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >> >> >> > > > -- > ------------------------------------------- > Ahmet > *"S/V Waterdancer"* 1990 Irwin 43 CC > "Tabasco" 1973 C&C 25 > Winthrop Yacht Club, Winthrop, MA / USA > ------------------------------------------- > >
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