Lay the gutted door face down and apply an absorbent such as paper towels or the sort to the inside. Soak the towels with Evaporust, and keep them wet the whole time it is in contact with the rust.
For my hood, my body guy made a pool out of plastic and filled it with a muriatic acid mix. He skinned the hood, and placed the skin in the pool and blasted the frame. When it was free of rust, he neutralized it, sealed it and welded the hood back together with new adhesive and epoxy primer. When done, he neutralized the pool contents and disposed of it......................Not bad for $300 bucks.
