An Acceptable Repair or Wimping Out?

Feb 14, 2014
7,400
Hunter 430 Waveland, MS
Is it the heat from a torch or saw that can light it?
Yes!

But not just those...
Depending on what are called "combustion limits", static electricity can cause a ignition. Watch what Diesel/Gasoline delivery truckers do... Clamp on a Grounding wired to reduce static sparks.
Jim...
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
You can do that with Liquid Gasoline too.:yikes: The match will go out.
That has not been my experience. I've noted that the vapors that inhabit the top of the container ignite immediately when flame is introduced. True, the liquid gasoline won't light, but liquid gasoline absent the vapors on top is a condition unknown to me.

Gasoline is flammable, while diesel isn't.
If you toss a match into a bucket of diesel nothing would happen but if you tossed a match into a bucket of petrol it’d be a different story.
http://drchemical.com.au/the-chemistry-of-fuel-petrol-vs-diesel-2

So, there's my reference. Do you have a reference, or perhaps experimental results, to back up your assertion?

My comments were based on my experience with boats that diesel is a much more inherently safe fuel than gasoline, and that under any atmospheric conditions we experience at sea level is not only much less likely to combust, it is downright difficult to get it to combust. Nearly the opposite can be said of gasoline. Gas in boats requires blowers, spark arrestors, etc. Diesel doesn't.

I see now that in a confined space, e.g., a fuel tank, with a cutting tool that is applying high heat, such as a torch r saw, one might get a diesel tank to explode. Point taken. But gas and diesel are hardly equivalent in this regard.
 
Feb 14, 2014
7,400
Hunter 430 Waveland, MS
No, it won't. Watch this:
Yes it will. ;)

My idiot friend did it. I told him, it is the vapors. [ a non-believer ]

So he took a liquid full coffee can and snapped on the freshness lid. No vapors on liquid top.
I stood wayyyyy back, hit lit a match, quickly opened the snap on lids, tossed the match on top of the Gasoline and....

Flame went out and no Ambulance needed. [before videos]:kick:

Check my link in my post #41 for the science.

Jim...

PS: I have never seen a atomic bomb explosion, but as a scientist, I believe A-bombs work.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
We weren't talking about 'quickly opening the snap on lid and tossing in a match before the vapors could appear.' If you must win an argument that way, then O.K., you got it!

But in real-world situation, ...let's say we change your experiment to just a couple of buckets, one half full of diesel, one of gasoline; go have a beer. Come back and start tossing matches. Report back.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
You can do that with Liquid Gasoline too.:yikes: The match will go out.
I just want to point out that James is correct in this assertion, in the special case of making sure there are no gasoline vapors on top of the liquid gasoline - a condition that does not occur naturally, at standard temperature and pressure, unless one has taken special precaution and implemented special procedures to make sure there are no vapors. And, having taken these precautions, it's perhaps important to note that this condition will not persist, and will likely cease to persist with seconds of having removed the special precautions. So. much like gasoline not igniting in an oxygen-free environment, it won't ignite under these conditions.

[This is meant to be humorous.]
 
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Feb 14, 2014
7,400
Hunter 430 Waveland, MS
you must win an argument that way
My chemistry professor told me that with known science, not much left to debate.

BTW I never argue on SBO, but I will point out differences, when it is "opinions" only once, but that is just me.:liar:

Take care, Nate is approaching me now.:(
Jim..
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
My chemistry professor told me that with known science, not much left to debate.

BTW I never argue on SBO, but I will point out differences, when it is "opinions" only once, but that is just me.:liar:

Take care, Nate is approaching me now.:(
Jim..
Good luck with the storm.
 

MitchM

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Jan 20, 2005
1,011
Nauticat 321 pilothouse 32 Erie PA
Diesel fuel has a lower explosive limit of 0.6 , an upper explosive limit of 7.5 , and a flash point of 62 °C (143 °F). so every body's right.....
 
Jun 21, 2007
2,105
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Best to replace the tank versus relocation. You want the weight on the centerline of the boat. 30 gals of diesel will weigh 210 pounds or so. I replaced a tank a few years back and documented with photos on this site. I used a Moeller tank for replacement as you are thinking and a little smaller to allow fuel to cycle more frequently, and allow easy replacement. Do a forum search, lots of good info on past projects like this. I used a six gallon tank temporarily to stay operational during the project. PM me if interested in the tank.
Jibes:

Appreciate your observations. And I've given that some thought. If I elect to decommission-but-not-remove the old tank which is on the port side ...(or even if I do remove it) ... The location of the new tank will be into a currently vacant area exactly opposite on the starboard side. The fore/aft balance therefore isn't affected. Into the equation: My two heavy group 27 batteries and an emergency start battery are located just adjacent to the existing tank on the port side. + Also the galley is on the port side. = My boat always had a noticeable port list. Installing the new diesel tank starboard might actually be a positive "mod" to the boat. There's a silver lining here!
 

Gunni

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Mar 16, 2010
5,937
Beneteau 411 Oceanis Annapolis
The CO2 method of tank demo is tried and true. In addition to fuel, tanks accumulate sediment and corrosion scale. No matter how much you attempt to clean the tank there is still a probability that residual sediment and scale will retain fuel and gas it back off as you go about cutting the tank up. By adding dry ice you introduce an inert gas generator which gives you a window of time to cut the tank. And as someone else said you don’t generate a waste product requiring treatment - oily water. Even with this method, compliance with industry standards would have the demo contractor moniting the tank for explosive gas limits. In one fatality that I am aware of the cutter took a break for lunch and when he came back the CO2 had disappated, volatile vapors had reestablished and he was killed the instant he began cutting again.
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Wow. I am now educated on this topic! Was it a diesel tank, or gas? What kind of cutting tool?
 

jviss

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Feb 5, 2004
6,745
Tartan 3800 20 Westport, MA
Interesting. I would not have guessed so. Is a nibbler considered a "hot tool?"
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
In addition to fuel, tanks accumulate sediment and corrosion scale. No matter how much you attempt to clean the tank there is still a probability that residual sediment and scale will retain fuel and gas it back off as you go about cutting the tank up.
A few years ago, I recommissioned an old gas tank that was in a used boat that I had bought. I pulled the sender, & cleaned out as much as I could. I then put in 5 gallons of high ethanol content gas & recycled it through a polisher for about a week, to wash out the the tank with fuel. I changed filters on the polisher probably twice the first day & then every other day after that. After a week, the fuel ran clean & got re-purposed as lawn mower gas. For the next year or two, I still got small accumulations of crud in the Racor on that boat, which I emptied every 3-6 months. That service interval has now gone to once per year. Things are finally starting to look clean for real inside that tank.

Yes, the residue & crud in the fuel tank takes a lot longer to fully clean out than most people would think possible. Soap & water does not get the job fully done. Purple power cleaner does not get the job fully done. Simple Green does not get the job fully done.