Fertan rust converter going into the doors.
After this the Fertan Rust Converter was left for 24 hours to convert the rust.
After checking that the conversion was complete the chassis members, voids and doors were flushed through with water to remove the corrosion by products that had been detached from the surface. That, and any surplus Fertan, ran out of the drain holes and the run-off can just be rinsed away. As Fertan is non hazardous and not harmful to water treatment facilities or the environment this causes no problems.
After washing out the vehicle was left in the warm garage for 24 hours to allow any remaining water to evaporate out. Washing out seems to alarm people but all the surfaces are protected by the iron tannate surface left by Fertan and it causes no problems. All these cavities have been wet in the past, that is why they have rust. Proper drain holes make this an easy process
Prior to flushing out Fertan can be seen
After flushing out the blue/black spots
This is the spray pattern from the extension supplied with the aerosol chassis wax.