On Thu, 13 Aug 2009 09:30:55 -0700 (PDT), sm_jamieson wrote:

What should I slap on them to stabilize the surface ?

I've used Kurust (another Hammerite product) to good effect. Converts
the rust to phosphates I think. Certainly stopped rust on bits of car
and on rusting corner reinforcement in plaster. The last bits on a
car have not been painted over and have stopped rusting.

http://www.hammerite.com/uk/products/ps_kurust.html
http://www.hammerite.com/uk/products...st_beater.html

--
Cheers
Dave.