Removing a fixed in Petrol Tank - any advice upon satety , please ?

[Capt Popeye]

Hi I am onsidering removing a metal Petrol Fuel Tank thats fixed in to the stern of my boat ; before I consider any further , might ask , are there any safety concerns that I should be aware of ? thank you ; is there any risks of an explosion handling an near empty metal fuel tank ? should I flush it through with water first to help remove any Petrol Fumes ? not ntending to use the Metal Tank again , replacing with Plastic carryable tank so that I can dump the Old Furl much more easily each season ; Thank you CP

 

[coopec]

Well I wouldn't smoke a cigarette while you are removing it.

I wouldn't use an electric drill or electric tool unless the tank was completely filled with water. Maybe remove any electrical connections?

 

[oldgit]

When the alloy fuel tank dumped 50 litres of petrol into the bilges of my Amercian Regal sports boat, it was probably time for action ?
A major undertaking as it turned out. Everything was glued to everything else.
First job was to remove all traces of petrol from tank and bilges. flooded with water and pumped the lot out.
Large amount of petrol had soaked into the foam around the tank.
The partical (I kid you not)wooden floor had been bonded in , this had to be sawn out manually.
The alloy tank had been glassfibred into the hull structure this had to be removed with an angle grinder.
When finally the tank was exposed a large amount of petrol soaked foam had to be cut away to allow tank to be lifted out.
The bottom of the alloy petrol tank was mass of small holes.
It had been laid on a bed of a felt like material which had absorbed water and caused the tank to corrode.
The entire world warns of repairing petrol tanks, so got some eyewatering quotes for a new one and even worse some considerable delay in fabricating.
In despair, wandered round to a outfit which makes tanks for racing cars and told them of my plight, was told to drop it round for inspection and ring back in the morning.
Rang back the following day and was told they could fix it, told call round later that afternoon.
They had welded a complete panel on to the bottom of the tank and charged me about £75.00.
The only other wrong with the boat was the appalling quality of the rest of the hull, the petrol engines which sometimes started and the Mercruiser outdrives which were designed to dissolve when exposed to water.
On the up side the cabin was lined with a sort of Orangey TEDDY BEAR FUR and other nautical refinements.
The roof flexed like nobodies business and the plastic window trims leaked like a sieve.
Other than that it was fine

 

[Spirit (of Glenans)]

My late father told me that if a petrol tank was to be welded, it should be heated up beforehand, to drive off petrol fumes.

 

[snowbird30ds]

I've welded fuel tanks before by putting the filler over the exhaust of a running engine, fumes only ignite in oxygen, failing that an old co2 fire extinguisher down the filler is even better and gives a better weld inside.
Just filling with water and emptying can still leave fumes to mix with the air drawn in as it empties.