Woolwax Hard-On is a high performance, permanent 1-time hard shell coating. Not rubber. Permanent One time hard corrosion inhibiitor. Auto / truck undercoating. NOT rubber. The surface should be newer and rust free. Hard-On is developed to be applied on new surfaces. It is not intended to be used on surfaces with surface rust. (Use original Woolwax for rusted frames). If you are not sure that you want a permanent (cannot be removed) coating, please contact us for more information. Once applied, there are no do-overs. Please consider this carefully. Looking for a permanent 1-time hard shell coating for your truck frame or equipment? Hard-On by woolwax is what you need. Originally developed as a chip guard for trailer trucks this formula is perfect for any long term applications. Hard-On is water based , so it has almost no smell. Dries to the touch in about 1 hour, and after 72 hours it is fully cured. Hard-On by Woolwax is an excellent solution for wheel wells which is always a high wash area. Hard-On is a water based coating that can be used on any metal surface. No smell. Paint or spray on.