Spent hours on internet trying to find the best way to remove oxidized paint on hardiplank last painted 7 years ago. FOUND MY ANSWER BY TRIAL AND ERROR. What finally worked was Cleansol BC (www.eacochem.com) 1 to 10 ratio in a pressure washer. The product says it has wax in it, but I couldn't detect a difference when used by itself. After letting it soak for five minutes, I used a RV brush to lightly scrub the hardiplank, just rinsing will not remove the oxidized paint. The oxidized paint "melted" off after brushing. Rinsed with medium setting on the pressure washer sprayer. Unlike TSP, there was no streaking. After it dried, I lightly sprayed Turtle Wax 1-Step Wax & Dry (can be found at any auto parts store), didn't bother wiping it down, but made sure not to put so much on it ran. It looks like a new paint job! The Wax should also help protect against future oxidation some. Sure beats another paint job!
Hardiplank is designed to paint (according to mfg) once every 15 yrs or so, do you really think any light spray on wax will still be there by then, and even if it is (which I'm betting there won't be), there are plenty of inexpensive products on the market that will remove any residual, all siding paint jobs should be pre-treated with a cleaner such as TSP. Turtle Wax 1-Step is not a heavy, buff on carnuba wax. In my book, it still beats a repaint job when it dosen't need it, but needs a facelift. BTW, how long does a wax job last on cars? quote=joecaption;902792]Sorry for not being excided for you but what you have done is ruin any chance of any future paintinig. Just not going to stick unless some how you get all that wax off.[/quote]