Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 09-12-2015, 14:09   #31
Registered User
 
Sun and Moon's Avatar

Join Date: Nov 2009
Location: Colorado
Boat: Bristol 29
Posts: 273
Re: Gas in Diesel Tank

The stupidity of so many posts continually astounds me. Adding gas to diesel makes it flammable and dangerous, and probably illegal. And as boatpoker pointed out, none of your systems are designed for this risk. It also decreases lubricity, which may damage your injectors. But it will kill the algae.
__________________

__________________
Sun and Moon is offline   Reply With Quote
Old 09-12-2015, 14:18   #32
Registered User

Join Date: Feb 2011
Posts: 2,105
Re: Gas in Diesel Tank

Quote:
Originally Posted by hamburking View Post
My Pearson (recently sold) originally had a gas Atomic 4, but was repowered with a Volvo Penta diesel.

Problem was, the fuel filler fitting was clearly marked GASOLINE ONLY. I usually had to sign a legal waiver stating I was aware they were putting diesel fuel into a gasoline fitting, and relinquishing them of all liability.

I wasted $40 (cdn, so about $15 US) on a little bottle of biocide before I found out a little gasoline would do the same job for just pennies (US, maybe dimes cdn).
Which it is, or most are.
__________________

__________________
reed1v is offline   Reply With Quote
Old 09-12-2015, 18:16   #33
Registered User
 
ozdigennaro's Avatar

Join Date: May 2014
Posts: 48
Images: 11
Re: Gas in Diesel Tank

(In a previous life I was a chemist.)

Gasoline and diesel are simply mixtures of hydrocarbons, different mixtures. They will mix completely.
2% gas in diesel will not be noticed.

(I admit that I don't understand the "lubricity" argument. I'm sure it's real but the effect will be quite minimal.)

Have fun. Don' worry!
__________________
Landlocked in Boulder, CO
ozdigennaro is offline   Reply With Quote
Old 09-12-2015, 19:10   #34
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Gas in Diesel Tank

Quote:
Originally Posted by ozdigennaro View Post
(In a previous life I was a chemist.)

Gasoline and diesel are simply mixtures of hydrocarbons, different mixtures. They will mix completely.
2% gas in diesel will not be noticed.

(I admit that I don't understand the "lubricity" argument. I'm sure it's real but the effect will be quite minimal.)

Have fun. Don' worry!
The lubricity is THE issue with modern common rail engines, as well as any toluene in the petrol that will harm the proportioning valve in the pump.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 09-12-2015, 19:17   #35
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: Van DeStat Super Dogger 31'
Posts: 7,331
Re: Gas in Diesel Tank

Quote:
Originally Posted by Sun and Moon View Post
The stupidity of so many posts continually astounds me. Adding gas to diesel makes it flammable and dangerous, and probably illegal. And as boatpoker pointed out, none of your systems are designed for this risk. It also decreases lubricity, which may damage your injectors. But it will kill the algae.
I think you will find that diesel is flammable even without gas
__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is online now   Reply With Quote
Old 09-12-2015, 19:22   #36
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Gas in Diesel Tank

Different flashpoints requiring different safety protocols.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 09-12-2015, 19:26   #37
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,454
Re: Gas in Diesel Tank

So, can anyone quote what the change in flash point for such small concentrations of petrol in diesel might be? I suspect that the petrol might flash off readily, but I don't know for sure. If it does, then simply waiting a while would rid the fuel of the petrol component. If not, then there is no enhanced explosion risk.

jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 09-12-2015, 19:52   #38
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Gas in Diesel Tank

Quote:
Originally Posted by Jim Cate View Post
So, can anyone quote what the change in flash point for such small concentrations of petrol in diesel might be? I suspect that the petrol might flash off readily, but I don't know for sure. If it does, then simply waiting a while would rid the fuel of the petrol component. If not, then there is no enhanced explosion risk.

jim
Waiting would probably allow the aromatics to evaporate if the tank is agitated but the compounds that affect the lubricity may well remain. Straight diesel does not give off flammable aromatics at room temperature but petrol does, hence the increased flammability danger.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 09-12-2015, 20:04   #39
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Gas in Diesel Tank

Quote:
Originally Posted by Jim Cate View Post
So, can anyone quote what the change in flash point for such small concentrations of petrol in diesel might be? I suspect that the petrol might flash off readily, but I don't know for sure. If it does, then simply waiting a while would rid the fuel of the petrol component. If not, then there is no enhanced explosion risk.jim
I bet if some pin head science person looked at this they would agree. How could the fumes of 6 gal of gas cause the 158 gal of diesel fumes to become explosive?
Did anyone mention the surface area of the tank? Where are all the fumes coming from? At what temp is all this happening? All this fume talk is bunk.
__________________
Guy is offline   Reply With Quote
Old 09-12-2015, 20:13   #40
Registered User
 
Sun and Moon's Avatar

Join Date: Nov 2009
Location: Colorado
Boat: Bristol 29
Posts: 273
Re: Gas in Diesel Tank

Posted by Evans Starzinger in another thread on this stupid idea. A 4% gas/diesel mixture has a flash point around 15C,59F. Think your engine room ever gets that hot? Honestly I don't mind if you blow yourselves up, but please don't take any unsuspecting passengers with you.

Gasoline as a Diesel Stablizer



__________________
Sun and Moon is offline   Reply With Quote
Old 09-12-2015, 20:25   #41
Guy
Registered User

Join Date: Feb 2013
Location: So. Oregon, USA
Boat: Seafarer36c
Posts: 4,308
Re: Gas in Diesel Tank

[QUOTE=Sun and Moon;1982879]The stupidity of so many posts continually astounds me. Adding gas to diesel makes it flammable and dangerous,

I think that is just about the most stupid thing I have ever heard. You do not need to add gas to diesel to make it flammable.
__________________
Guy is offline   Reply With Quote
Old 09-12-2015, 20:45   #42
Registered User
 
Sun and Moon's Avatar

Join Date: Nov 2009
Location: Colorado
Boat: Bristol 29
Posts: 273
Re: Gas in Diesel Tank

flam·ma·ble ˈflaməb(ə)l/
adjective:easily set on fire

Strait diesel has a flash point of over 125 degrees and is not easily set on fire. Go try it sometime. Gasoline is easily set on fire, as are its fumes. Gasoline powered boats have more stringent safety requirements than diesel powered boats do.
__________________
Sun and Moon is offline   Reply With Quote
Old 09-12-2015, 20:46   #43
Registered User
 
NoTies's Avatar

Join Date: Nov 2005
Location: Vanuatu
Boat: Whiting 29' extended "Nightcap"
Posts: 1,378
Images: 2
Re: Gas in Diesel Tank

Quote:
Originally Posted by Guy View Post
I think that is just about the most stupid thing I have ever heard.
Oh the irony. Did you even look at the chart??? It's not about flammability, it is about flash point. 4% dilution of petrol lowers the flashpoint over 40 degrees to under 25 dgrees celcius, cooler than the average engineroom.
__________________
Pete

Positively, socially deviant.
NoTies is offline   Reply With Quote
Old 10-12-2015, 06:12   #44
Registered User

Join Date: Feb 2011
Posts: 2,105
Re: Gas in Diesel Tank

So in theory gas by itself will self ignite. Thus cars should be blowing up all over the place. Carpenters use to fill nail kegs with gasoline, no cover, just wooden barrels(pony size). Should have flashed over before the buildings were finished. Of course a diesel works by compression of gas, not by a spark plug. You can compress gas to kingdom come and not much is going to happen. However make it into an ultra fine mist and then compress the droplets, they will go bang. Compress it while removing the excess heat from compression and nothing will happen(why cold engines knock).
BTW, unless gasoline has reached a certain vapor point, it will not do much. Refine diesel and you get gasoline. Both can be ignited with open flames, explosions, or extreme heat(which works by converting the liquid to a gas).
Meanwhile all those folks who have added gas to their diesel for over a century probably should have been blown to bits by now according to the recent posts.
__________________
reed1v is offline   Reply With Quote
Old 10-12-2015, 06:23   #45
Writing Full-Time Since 2014
 
thinwater's Avatar

Join Date: Nov 2008
Location: Deale, MD
Boat: PDQ Altair, 32/34
Posts: 4,337
Re: Gas in Diesel Tank

[QUOTE=Guy;1983202]
Quote:
Originally Posted by Sun and Moon View Post
The stupidity of so many posts continually astounds me. Adding gas to diesel makes it flammable and dangerous,

I think that is just about the most stupid thing I have ever heard. You do not need to add gas to diesel to make it flammable.
Don't post statements without basis. Embarrassing.

The definition of flammable is related to the specific code (dictionary def in this case is for casual use and is not specific). It is ALWAYS based PMCC (closed cup flash point). Liquids with flash points greater than these figures are combustible liquids, which are very different (flammables liquids have vapors which can ignite, un-heated combustible liquids do not).

Code Flash Point
EPA 140F
Building Code 140F
Road transportation 100F (assumption is that spills are in the open)
Marine transportation 140F

Home heating fuel (#2 oil) is required by code to have a flash point >140F, and in general it is very close to that. Road diesel is sometimes blended to 110-125F, but that is ONLY for road use and would be unsafe in a boat or home.

Folks get away with all sorts of things, but not forever. I've done 2 accident investigations related to gasoline getting mixed in the fuel. Things were blown apart. In both cases the ignition source was static. This cannot happen with diesel. Practices are much different for flammable liquids.
__________________

__________________
Gear Testing--Engineering--Sailing

Writing full-time since 2014.
Bookstore:http://sail-delmarva.blogspot.com/20...ook-store.html
thinwater is offline   Reply With Quote
Reply

Tags
diesel

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Gas Station Diesel vs Marine Diesel Rocketman Engines and Propulsion Systems 75 08-05-2016 20:31
Using small Butane Gas Cylinders as backup to main Gas system simonpickard Liveaboard's Forum 5 14-03-2014 09:39
Diesel Fuel Tank vs Portable Diesel Fuel Cell GaryMayo Engines and Propulsion Systems 11 13-11-2012 16:47
Diesel Tank Configuration (Sublevel Tank no.2) erasmos Engines and Propulsion Systems 2 14-04-2011 14:57



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:14.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.