Snapped Bottom Bracket

first of all i apologise for hijacking your thread. it was just that it was the most recently posted in the mechanics section and i really need some advice pronto.

Right now, i have no money to buy some track wheels to complete my most recent bike project so im converting the rear wheel that was originally with the bike. So far ive got the sprocket held in place with a BB lockring. With no brakes im worried this just wont hold and it will end up with me in hospital. Soo... my mate wants to weld the sprocket onto the hub... tomorrow morning! Is this possible?? Is the metal types suitable for welding? I just dont know. Have people done this before? I know this is a bit of a long shot hoping for advice before tomorrow morning but it thought it was worth a try.
cheers!

I hope you're joking talking about welding the cog on the hub.
Excuse me if I sound harsh, but if you say you have no money to buy brakes, neither you've a proper track cog with it's lockring.... erm... you should understand that it's not only your life that's put in danger, but anyone else that is on the street. If you were on Oyster card and no bike, it would cost you a lot more. Have your teeth re-done costs even more. Injuries to others a hell of a lot more.
Do yourself a favour :)