i am re-working my fuel system, whats the best way to defumigate a petrol tank? i seem to recall filling it with exhaust fumes would this be ok as i need to weld in a return for the fuel injection?

Phil

are you going to weld it?

very difficult to get them clean enough, I've tried washing them with a hose and pouring in Gunk plus washing up liquid, then welding it full off water. The damn thing still went bang and blew water out the filler, scared the poop out me

Safest way is to fill it with water while welding and just have a small air-space at the top where you are welding , then use paraffin to check for any leaks .

safest way is to get someone else to do it.

Then i'd fill mostly with water, start the car and run a pipe from the exhaust into the empty space in the fuel tank.

I'd also check for leaks using lightly compressed air and soapy water. If you need to weld again, I'd guess having had parafin around may be a pain.

(although having never actually done any of this, take my words with a pinch of salt)

I have welded hundreds of tanks so I suggest you do the following:
Make sure that the tank contains no hidden swirl pots or compartments.
Wash the tank with washing up liquid and water.
Run the opening of the tank on a car exhaust for about 20-30 mins.
As a final check, a bit of lit newspaper on a long bit of tube over the opening.

I have never had one even make a pop, even when I have brazed bike tanks.

Cheers guys, i'm going to go for it right now i will let you know how it goes if i'm not in A+E

Phil

All done thanks for your help.

Which method did you use?

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Originally posted by nitram38
Which method did you use?

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