OK, so I've ordered some of those push in fittings referred to in an earlier thread. Just needs a half inch hole drilled near the top of the tank, push in the rubber bung, then push the metal fitting which expands the bung and forms a seal.

Thing is, is the petrol tank going to explode?

I've thought of running a pipe from my mig welding gas into the tank to fill it with CO2 and Argon. Will that stop it from exploding, or not, or maybe it isn't necessary anyway?

John

If / when you drill it use a air drill no sparks from a motor

conect it to a car exhaust pipe it will be cheaper

When I added a pipe to mine I filled with water then drilled, when welding the new pipe in place let a little of the water out and backfilled the air space with argon.

In my braver younger days I welded a rangerover fuel tank in situ, just ran the exhaust pipe into the tank to fill the space with fumes, left car running when welding. Maybe not recommended approach

as long as your drill isnt sparky you wont have a prob....i didnt..petrol fumes go downwards so drill from the top and de-burr the inside of the hole before you put the rubber in...DONT try to remove the elbow once it,s fitted as it will split

Nice and slow, keep the heat down....

The exhaust into the tank is the time honoured way of removing explosive gasses, just make sure the missus isn't around when you borrow the vacuum ckeaner hose.

had this conversation with one of my tutors at college and he said dont use water but completely fill the tank with fuel because the mixture will be too rich for the fuel to ignite and it will not burn. i think im going to let hime sort my tank

I would say that as you are drilling a hole in an alluminium tank it wont be a problem, no sparks from ally, and just use a hand brace to drill with, no sparks there either, and jobs a good un! Cheers Ray

Out of interest, bare aluminium is considered a serious safety risk on oil rigs and in refineries and the like - dropping a rusty steel tool on bare aluminium can create a reaction (thermite reaction) the energy released can ignite an explosive atmosphere that may be present. Just to make you all feel safe about drilling aluminium fuel tanks

Drain tank, fill with water, re-drain, re-fill with water, drain, drill, job done.

Just empty it of fuel , Purge it once with water to get rid of the majority of the vapour and drill slow and sure.

If your really scared Keep it filled with water as you drill it (ps use a manual or Air Drill to avoid electric shock) .......

Personnally I would drain out the fuel and just drill it slow, after leaving it open to vent for a day or two.

Now if you were to be "welding" a fuel tank thats completely different...........

Having had an uncle killed by a fuel tank that had been standing open for weeks before he cut it (albeit with a gas torch) I don't think you can be too cautious - certainly make sure it is filled with non- combustible gas before drilling and use a hand drill to keep speed & heat down.