I proposed the plan to four people.
Rusty van roof.
Be sure to look in non obvious places.
Rust hiding behind the panels caused by leaks in the roof gutter firstly to uncover the surface rust on the van s body i looked for brown marks bubbles under the paint and flakes.
The idea was to make a frame cover it with 22 plywood anchor it the van with screws fill the voids rear corners with spray foam red cans that cost about 3 at a hardware or building supply store coat this with laminating resin fiberglass over the corners and edges of this structure first with 1 1 2oz fiberglass mat then over the entire structure with 10 oz.
This problem is particularly acute on minivans and large vans.
Inside the van the footwell steps wheel arches behind the dash and under any old plastic trim or flooring for example.
Ospho neutralizes rust turning it into paintable black primer.
I ve found the best all round rust removal tool is a twist wheel wire brush for an angle grinder.
Plan to spend about 100 on supplies like sandpaper primer masking tape and poly sheeting a tack rag polishing compound and touch up paint and clear coat.
Here are their responses.
Sand the roof lightly with 200 grit sandpaper to remove some of the rust and to prepare the roof for step 2.
Apply a product like rhino liner herculiner or rust oleum truck bed liner to the roof.
Use a coat hanger or pipe cleaner to make sure the holes remain open.
We brushed ospho rust treatment onto the remaining surface rust near our repair area.
It takes a lot of time and elbow grease to remove rust on a van but having the right tools really helps.
Another way to prevent rust is to keep the drain holes clear on the bottoms of doors and on the rocker panels the area below the doors so water can t accumulate and cause rust.
To stop the rust on the rest of the roof where there were 6 8 patches of minor surface rust we brushed por 15 on then sanded it down with 400 grit sandpaper once it was dry.
First thing i d do is surround the rusted areas by several layers of durable masking tape so as not to damage non rusted finish along with an equally thick couple layers over the top edge of the window glass then scrape the bubbled paint away and sand with multiple grits of sandpaper say 80 150 grit.