It will all depend on the shape, meaning is there any rust on the surface????
also make sure before you apply that you degrease, I have done many slides in KG Gunkote and its easy to DIY, if you dont mind paying for the Job you might be able to get Will at RedJacket to do it eventhough he is probably super busy but I have heard great things of his coating technique and setup as everything is temperature control but it is def something you can do.