diesel fuel tank drilling?

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woody001

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Hi,

If i empty my diesel tank, remove it from the boat, flush it, will it be ok to drill a hole to add a fuel tank gauge?

I have been informed it is against the law for a car garage to do this, even on diesel tanks.


I dont fancy blowing myself up.

thanks

Simon.
 
either drill the tanh upside down or put grease where you drill,stop the swarf getting into the tank.how are youfixing the gauge.
 
You can take a can of diesel .... throw a match at it and the match will go out on contact with the diesel unless sufficient temp ..... I mean hot ! to generate enough vapours to ignite.

It is a common misconception that the liquid burns .... no it is the vapour layer at the liquid surface that burns .... the flame once lit and sustained generates more vapour to keep it alight.

Diesel is one of the safest fuels ........ BUT once got alight it is a strong burn ..... and the fuel is at temperature that readily lights again if not cooled.


Your biggest worry is not any bang or fire .... but the swarf you will generate cutting the hole ... which you must prevent from getting into the fuel system.

For cutting the hole .... I don't know what size hole you need ... but could a hole cutter for a kitchen sink do the job ?? or how about fitting the gauge to the sight plate ? Just thoughts ....
 
Fill it with water when you drill it - it is the residual vapour build up in a confined space that can be a problem and dont use a mains powered drill with water everywhere.
 
I'm sure that there is little or no risk of it going bang. Just flush it out well and do it in a well ventilated area. I did it last year with no probs.

It does remind me of another story though

The son of a good friend was helping out on a farm and on returning to the workshop had to walk past a guy who was using an acetylene torch to cut a 44 gallon drum in half. The drum had been used for storing some or other chemical that I cannot remember the name of but had been flushed and had the cap off for months.

To cut a long story short, as he walked past some 5 meters away, the thing exploded and the blast of air that was sent out of the hole in the top just about too his calf off. Do not look at this if you are faint hearted

The rather bewildered chap who was doing the cutting was unscathed.

There you go
 
I have gas welded a diesel tank after flushing it out with water a couple of times. Just to be on the safe side I partially filled it with water to minimise the void space but I doubt if this was really necessary. Drilling poses no appreciable risk.

Petrol is a different matter altogether and I would definitely not do the same with any vessel that had been used to contain light hydrocarbons.
 
Steam cleaning is the best way. I wouldn't worry too much about a little bit of swarf as it will be captured by the fuel filter.
 
I've previously emptied my diesel tanks and cut & fitted inspection hatches + sender unit with no problems. If your tank is stainless steel keep a fairly slow speed and steady pressure whilst drilling otherwise the material seems to surface harden. If you want a large hole use a hole cutter with cutting compound. If you fit an inspection hatch you can clean out the tank thoroughly. I used a piece of putty to pick up swarf from the inside of the tanks.
JJTOP
 
[ QUOTE ]
cool, what about risk of it going bang?

[/ QUOTE ]

the trick with petrol tanks is to evacuate the vapours by adding carbon monoxide via the car engine exhaust.
you can then weld it with now probs ( honest , just had a word with St Peter ) /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif /forums/images/graemlins/shocked.gif
 
when I were a lad and driving tractors, the mechanic would fill leaky diesel tanks and then weld them - seen him do it with the initial dribbles in flames but no bang. So I endorse what others have said. Filling with water sounds sensible.
 
[ QUOTE ]
when I were a lad and driving tractors, the mechanic would fill leaky diesel tanks and then weld them - seen him do it with the initial dribbles in flames but no bang. So I endorse what others have said. Filling with water sounds sensible.

[/ QUOTE ]

IF A FLAME IS INVLOVED WATER IS TANTAMOUNT TO SUISIDE AS FUEL AND VAPOUR FLOAT ON THE TOP OF THE WATER.
BELIVE ME I TRIED IT, LUCKY TO BE HERE.
IF HEATING FUEL TANK PARTICULALY PETROL EVACUATE WITH CARBON
MONOXIDE FIRST.
IT WORKS
 
[ QUOTE ]
EVACUATE WITH CARBON MONOXIDE FIRST.

[/ QUOTE ] Carbon monoxide is a flammable gas. Lower and upper ignition limits 12.5% and 74% respectively.

Perhaps you meant carbon dioxide.

If you are going to give dangerous advice like that it would be better IF YOU DID NOT SHOUT.
 
[ QUOTE ]
the trick with petrol tanks is to evacuate the vapours by adding carbon monoxide via the car engine exhaust.
you can then weld it with now probs ( honest , just had a word with St Peter )

[/ QUOTE ]This is dangerous nonsense. Sorry to be direct to the point of rudeness but your advice could kill someone. Not only is CO a flammable gas itself, cars no longer produce more than a few ppm of CO (have a quick look at your last exhaust gas analysis).
 
Perhaps not quite that dangerous as the exhaust gas will contain carbon dioxide, water vapour and of course nitrogen, pre catatytic coverters about 2.5% carbon monoxide and very little oxygen (petrol engines) but any liquid petrol left could vaporise and still ignite outside the tank.

Welding on diesel tanks is also dangerous because locally the residual oil could be vaporised and ignited. FWIW the ignition temperature of diesel is lower than that of petrol depite its much higher flash point.

Steam cleaning is the only acceptably safe method of cleaning either petrol or diesel tanks. Personally though I would be happy to cut a hole in a diesel tank with a tank cutter or drill provided it was only driven slowly ie by hand.
 
[ QUOTE ]
Perhaps not quite that dangerous as the exhaust gas will contain...

[/ QUOTE ]I think that mucking about with hoses on car exhausts and attempting to fill a fuel tank with 'inert' vapour in order to carry out hot-work on the tank is about as dangerous as anything I've ever heard of!
 
This guy asked us "could he drill a hole in a diesel tank" without killing himself?

Answer YES - no probs go ahead and do it!

If you give the tank a quick flush with water (not really necessary) then there would never be enough vapours in the tank to ignite by drilling. In fact if I was doing it, I'd probably fill the tank with diesel to prevent a fire???
Having been shown as an apprentice someone throwing a lighted match into a can of diesel - only to see it go out, then the same person took a lit rag and held it over the diesel for about 4 minutes before he got it to light and then there was no "explosion" only a weak flame.

Gezzs give me strength /forums/images/graemlins/tongue.gif

Instead we've got the guy trying to connect up a car exhaust to the tank, steam cleaning it and God knows what - totally un-necessary
 
Its incredible .... in fact unbelievable ...... and Ignition temp ???

As Boatman says ... a simple hole cutting in a tank has developed into a debate including some pretty daft unnecessary measures.

I am also intrigued by the "Ignition temp." statement of Diesel lower than petrol ..... by another post ... I'm trying to look through broad analysis of both products to find such a phenonema .... can't find anything like it ... perhaps the postee can explain more .... ???? As the only time I can see that diesel will ignite at lower temp than petrol is when diesel is compressed seriously and petrol not............. I must be missing something here ....
 
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