
Following on this thread I had my Z50 S/Arm shot blasted there and it came up pretty much as expected - lots of small pockmarks where the surface rust had eaten it away but I thought a spray-on filler would help produce a nice even finish when rubbed down ready for priming and top coating. Not so - using my new super expensive spray booth (see other messages) it proved very awkward to get an even distribution of spray paint over the swinging arm as most of the paint decorated the back panel of the spray booth. Some even landed on the swinging arm crossbar which was the worst bit but didn't give best results . Plan B me-thinks (if I had one)
I stripped all the old paint off back to bare metal

and using one of the most useful power tools I've ever bought.- a B&D Powerfile.

Using a medium grade belt I gently coaxed all the pockmarks and pitted surface marks off and without taking too much metal off sort of polished it back to a shiny bare metal surface all ready for priming. These powerfiles have a 1'" nose on them and can get into some of the most awkward recesses where grinding disks can't get at and can save a lot of time and hard graft.
Pic may not do justice to the job but might give some idea of how to go about it.
Hope this helps a few enthusiastic amateurs like me!
Brian