I am doing a cpmplete restoration of my early (no holes) Sub-frame. What is the best way to strip my front Coil springs. I have been told that sandblasting will take tempering out of the spring, is this true? Will chemical stripping hamper the tempering? These are the originals, and the car sat good prior to dismantling. I don't think they have "weakened" over the years. Thanks for any advice!!!