This afternoon, after delays due to lots of rain and back problems, I have finally got around to applying the rust converter. Bought from Carter Cash. Four coats need to be applied, leaving 5 minutes between each one. The top photo shows the 3rd coat and the bottom one the final one. By then I had to move Mega Breadvan into the garage as it started to spot with rain.
The next job will be two coats of metal primer.