Do any of you use an oxy-acet torch for exhaust work?

I have some exhaust work to do on an old project Nissan and I'm wondering
if
any of you use gas torches for this?  If so, what do you best suggest for
the filler?  I've heard that coat hanger and bailing wire material works
well but I also have some rods kicking around.  Do I need to grind the
tubes
much??

Thanks for any input you might have.
Andrew.