Quote Originally Posted by Absinth View Post
Molasses is good for cleaning rust from steel.

Caustic soda is good for stripping paint from plastic parts, it is available from Bunnings and dilute as per instructions. Caustic soda won't hurt the plastic no matter how long you leave it in.... I've left a fascia in it for three months to get all the paint layers off it that previous owners had applied.

caustic soda burns like hell if you get it on your skin so wear protective gear and keep your tub covered and away from children or pets. I was using a wheelie bin in Melbourne but will have to find something better now we're in Parkes..
I have two tubs for de-rusting, one with molasses and when I remove the items I hose them off and drop them in a tub with a capful of Napisan. This neutralizes the acid in the molasses, otherwise the thing will flash rust as it dries. I rinse the item with fresh water when it comes out of the Napisan and then either dry it with an old flannel shirt or just leave it in the sun. Just make sure you give any item done this way a really good clean before you paint it, the Napisan needs to be completely cleaned off or paint adhesion can be a problem, the same as soda blasting.