I have a question for the pros out there. A buddy and i were discussing the topic of upgrading panels and this what brought up. My buddy has been an electrician for i would say at least twenty years and he said when upgrading a recessed panel it is okay to put the new surface mounted panel over the old panel, using it as a splice box. This means he would have to grind down the lip of the old panel to accomplish this task...for some reason this doesnt sound correct to me at all. Has anyone used this technique and is it legal.

I don't think it's right because you can't easily gain access to the old panel. Using the old panel as a JB is ok if you have it accessible (i.e. through the front cover being removed.)

I have demo'ed quite a few that where installed like you descibed. It's certainly not the first choice for a proper installation. You can allways install the new panel in place of the old one......even if a small amount of sheetrock repair is required.

GJ