Foam Filling Fuel Tanks

Ok I know this is going to sound daft but....How do I foam fill my square shaped, aluminium petrol tank? Do I clean out, make safe etc and cut it open or will that just burn the foam when I'm re-welding? Or can I just try forcing the foam into the filler?

Get the little square foam cubes, stuff them in the filler neck, put too many in so they stick up the neck so when you fill it up with fuel it splashes all over the car and your race overalls.
Then you have to start poking around with bits of hooked wire to try and get a couple back out only to find bits break off and you can't get them out.
Well that's what I did.
:o

Dont forget the guage sender if you have one fitted. Being an alloy tank,are you sure its not already done?

As Tim says, use the foam cubes. If you half-fill with fuel then bung some cubes in, by the time you've trailered to a circuit they will have distributed themselves around the tank and you will be able to add some more. Repeat until it won't take any more.

Brilliant Eric. Best description of my normal race day ever!! Only without the foam.
Terence, I went for the 'cheap' unfilled option. I know....hindsight and all that......!

Tim - I read that and thought "that's exactly what I would have done" :D

>>>>>>>>>they stick up the neck so when you fill it up with fuel it splashes all over the car and your race overalls.

You also find when you buy force 6 gallons of cubes into a 6 gallon tank that the "stuff" already inside the tank jams the foam and it takes 10 minutes to fill with petrol. You have to jack the car up to get the angle "just right" before you can get in enough fuel for a race.

Don't ask MGDavid and I how we know!

My mate made me a tank and put big squares of foam in it before he welded it up. He just pumped an inert gas in it while finishing it off.
I also fitted a serrated hard plastic pipe inside the filler neck to the bottom of the tank and have never had any trouble filling it .