Do not wonder, it's an absolute must. Once you're past the open window of chemical bonding you have to create a mechanical bond by scuffing the area to be painted. You will not have to tell your painted to scuff, as I'm sure he'll know that.

Thanks for sharing my videos guys. I've learned a lot from people and it's great to share that with others. Let me know if there's anything else I can help with.

Also, thanks migsBIG for selling me the disc brakes last year at the Van Buys swap meet. It was good getting to meet you. Send me a PM if you need my number or I can help your painter in anyway with the Organosol.