Noticed a strong smell of fuel when i was in the garage earlier and upon inspection i found a fuel leak from the in tank fuel pump on my BEC MK Indy.
Upon removing the pump i found that it does not run an o ring to seal it but had a very small amount of rubber type sealant.
What is the best thing to use to make a good seal between my pump and tank ??

I used an ali metal chemical weld for a crack in my tank which has worked a treat.

Make a cork gasket, the chemicals in the fuel will perish rubber.
Cheers,
Bob

Viton is the stuff these days. Nitrile does not cope long term with the ethanol in petrol. Even the cork gaskets use a nitrile based rubber to make them, I checked all sorts of places (on the net, in shops you just get told "that is what we have always sold" for the specs. Saying that, there was a viton based cork gasket material, but not easy to buy...

Viton O rings easy to get, try "simply bearings"

petro putty, great stuff and worked a treat for me.

Hylomar blue if you want silicone sealant style stuff that is fuel safe.

Went with the Hylomar Blue and so far so good.Thanks for all the replies