Using a grinder around fuel tank

[ReefchiefReece]

whats up guys

Im busy restoring my floor pans ,the paintwork around my tank and the tank itself and wanted to know if its dangerous to use a grinder with a brush attached to it as iv been told it the sparks can cause an explosion.

I have removed the tank already and cleaned it with vinegar and bicarb and have flushed it with water but a few people have told me that there can still be vapours inside the tank so my questions are ... is it safe to grind on the tank if it is filled with water and is it safe to grind around the fuel tank area with the fuel line clamped off ??

Any advice or knowledge on this will be greatly appreciated
Shot

[theKbStockpiler]

It's always going to be safer not to take chances with that stated first;

-Heat sources around a gas tank are most dangerous the warmer it is because the fuel is evaporating faster.
-If you can smell vapors ,NEVER get a heat source any where near the car.
-Fuel vapor gets trapped in the metal structure. JUST washing without steam (or however it is professionally done) is NO ways good enough. If you wash a fuel tank out with hot soapy water ,let it dry and then put a lit match at the filler hole , a 50 foot flame will shoot out of it. NO joke.This may not be true if the tank has been empty for several years.

I used to weld maybe a few feet from what I thought was a perfectly sealed up gas tank and one day I noticed a pretty blue microscopic flame at the edge of the filler hose. It was so damn small it was hardly visible. Now if I weld a car with the "presumably perfectly sealed up tank" on the car period, I use a fan to diffuse trace vapor that could seep out and use other measures as well.

-I think a flame is much worse than a spark but that is only based on my own experiences. I still would never let anything that could have fuel vapor contained in it be hit with sparks or hot metal thrown from a grinder.

If I could not smell any gas ,was more than 2 feet away from anything that could contain fuel, even a EVAP hose or canister, had a fan blowing in the area to diffuse possible trace vapor , I would use a grinder if I was directing the sparks away.

With all of this said ,a rotary wire brush should be less hazardous but I would follow the same rules as I do with a grinder. I soft wire brush is going to be much safer than one of those extremely tough ones that is a grinder attachment. I would not personally use a grinder attachment wire brush on anything but cast iron or basically metal 'plate' for that mater.
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My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[ReefchiefReece]

Okay thanks so i won't be taking that chance then haha
Will use a brass drill brush instead for the tank.
But what about the pan?? do you rate i will still be able to grind in the interior if my tanks been removed and the fuel lines been clamped or is there still a chance that the vapours could be in the air (tanks been out for about a week now and the area is well ventilated)

Not to keen on my garage blowing up due to people living above it lol

[theKbStockpiler]

What will happen is vapor will escape from the tank if it's not sealed perfectly and basically leave a 'trail' of vapor that leads back to the tank. To combat this possibility;like I have already said, is to use a fan to move a little air around the fuel tank or anything else that vapor could escape from. Then instead of a vapor 'trail' leading back to the tank you have diluted vapor that can't ignite.
_________________
My beetle is not competing with your beetle. I have the yellow beetle in my town. There is a red one, a green one ......
Use all safety devices including a mask.

[57BLITZ]

Open up your fuel line (disconnect it at BOTH ends) and blow out the line with compressed air.
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Jesucristo es mi Señor y Salvador!

[viiking]

Fill the tank completely with water. Explosions cannot happen in a tank with no air.

Liquids do not burn/explode. Only the vapor above the fuel!

Also be careful using a fan around the fuel tank. It is an ignition source as well!!

[boxkiteflyer]

+1 viiking
As an aside, in the 1930s some air race pilots had leaky fuel tanks in their home built racers (the Folkerts SK-2 'Toots' was notorious for having leaky aluminum fuel tanks) so they filled them with water and welded without problems other than the tanks leaking elsewhere so that the whole process had to be repeated after about each race!

[viiking]

Yes that is a common practice.
My background is the petrochemical industry. I regularly supervised welding over the top of gasoline-like solvent tanks. These were always filled completely with liquid (solvent) and any tiny Vapor space that might have been left was inerted with nitrogen (or CO2).Of course the immediate airspace around the weld site had to be checked for gas i.e. LEL/UEL (lower/upper explosive limit).
It was always hard to explain to people that standing on a 10,000 gallon solvent tank and welding wasn’t crazy. Lasted 40 yrs in industry and never had an incident.