[GStage1]

Go to Home Depot and get a gallon of phosphoric acid....green liquid in a translucent bottle. Use a brush to apply it and let it sit overnight...it will chemically neutralize the rust. Wipe off any white residue with acetone or lacquer thinner. Prepare the panel for paint like a new metal panel.

[Greg Reid]

Originally Posted by GStage1

Go to Home Depot and get a gallon of phosphoric acid....green liquid in a translucent bottle. Use a brush to apply it and let it sit overnight...it will chemically neutralize the rust. Wipe off any white residue with acetone or lacquer thinner. Prepare the panel for paint like a new metal panel.

From reading this, you seem to imply that it's not necessary to actually remove the rust, just wipe the white coating off and paint?
I've used this product before but I kept wirebrushing until I no longer saw any rust. Is that not necessary?