Firstly great to have a site where us consumers can get good information. I am restoring an old car and have just sanded and wire wheeled the floor pans, and behind the dash where possible.  Then put a rust converter over the metal.  If I use KBS three step, do I have to completely remove the rust converter to ensure adherence? Do I have to cover up bolt holes to be used for future use, and/or insert bolt to be removed once process complete and if so will it be difficult to get them out.  Lastly (for now) if at a later date I need to weld over a part of the surface, can I do so as I realise I will not get the rust seal off?      

It would be best to get rid of the rust converter in order to get the best possible adhesion. The RustSeal does add some thickness (minimal), so we do advise against coating the threads with RustSeal.  Go ahead and insert a bolt into the bolt holes to protect the threads.  You can put some torque on the bolts at a later time and remove them once the RustSeal is cured. You can weld where the RustSeal is.  The RustSeal will simply burn off in those spots.  You can then do the KBS 3 Step System on those weld spots after the weld has cooled to room temperature. As always, please let us know if you have any additional questions.