Rust protecting your car

[Ivan141]

Wow....nice write-up Mux! Brings up many interesting points for me since I want to get rid of quite a few rust spots. Lets take my "new" doors for example. They have some surface rust on the outside which is very difficult to remove, the rust has eaten in, creating a rough patch that doesnt go through the sheet steel completely. Sandblasting it with smaller particles might do the trick without going completely through the bodywork, but remains risky. Then there's the rust converting substances approach, but the problem is that it is a very uneven surface, which might not be completely cured using such a substance.
On the bottom welds there are a few rust spots as well, as on every other door that hasnt been treated yet. Sandblasting seems to me a better way of stopping that rust.
What would you think is the best method of effectively stopping rusting to continue on sheetmetal, and especially the welds on it. The method of bodypanel welding is VERY prone to rusting on ae86's, just take a look at the rear body section above the rear licht clusters, ugly overlap welds everywhere.