underbody sealer

hi guys I am working on getting my uc ready to put under body sealer on and I want to rust proof it first, I was wondering if any of you guys know what I should use? the rust is mainly light surface rust .
I have water blasted and lightly wire brush the surface and just want something to kill the rust before I brush the sealer on.

any help will be great

cheers antony

A few people seem to like POR 15. It's around $90 a litre. There are a couple of threads already about this product.

There's a product called Galmet ironize, known as rust convertor. It recommended on surfaces where you have crusty rust.
Going by the instructions, remove all loose scale rust etc, probably blow it down then apply the product by brush. It then drys and converts the rusty surface to a chellite condition where you then spray it with there own undercoat and then finish product.
The 3 Galmet products i used cost about $40-50.
Also the good thing about this stuff is it prevents the rust occuring in that spot ever again and you can apply other paint products once the final top coat has been applied.