"Naval jelly" rust dissolver = is sold at many places like Home Depot in the USA in the paint department and = most auto stores that sell body work stuff.
 
It is made by the Loctite = corporation. north America group, Rocky Hill, CT 06067 and Mississauga, Ontario, CANADA
 
Of course you need to remove rust = as much as you can with a scraper, wire brush or sandpaper wheel but with = several applications (and in some cases only one) will eat rust down to the metal.
 
You'' find it. great product. = Just be patient and do more prep than you think you will need to then look again = for more rust. On my bumper hitch , at least 5 times when I thought AI was = done I found more rust. I guess the naval jelly loosened stuff I did not see = with the bare eye.
 
William
Vanagon site http://mem= bers.home.net/holisticdream/vanagon1989.htm
Holistic Health Center site http://mem= bers.home.net/wholehealthfound/welcome.html