The rusty boot in my old Discovery 300TDI is not unexpected. Just about any Disco of this age seems to suffer. Anyway, old boot floor was taken out (see previous post) and a nice new one welded in by the father in law. To do this I drilled what seemed like a million holes in the new boot floor and he welded through them. This should give something akin to the spot welds originally used – they may actually be stronger as there are more weld points.
As you can see in this picture, there weld holes are a bit rough, but no one is going to see them so I don't need to grind them off. Everywhere has had two coating's of high zinc primer (80% zinc) and on the inside of the landy there is bit too generous coating of Hammerite.
You can see in the picture above the nice coat of zinc primer and the first coat of Hammerite black. Each of the weld points has this treatment as have areas that are likely to rust (gullies around the boot floor etc).
Areas not exposed have also had a coat of galv repair zinc spray (95%+ zinc) then a good spray of Waxoyl. This should help keep these areas rust free for many more years. None of it looks elegant though, but you never get to see it so who cares!
Now time to put the internal trim back together and replace most of the rusty screws, washers, nuts and bolts with stainless versions.