I have a #7C Record Jointer that I need to flatten the sole. (Yes, I flatten the sole on all my bench planes) Usually I use silicon carbide sandpaper wet on a granite block, but the jointer is just too long for my 12" granite piece.

I have an extra cast iron wing for my table saw that I intend to use for this process. But I have a question as far as the best process however. Would it be best to just adhere the sandpaper to the CI top and do it dry, or wet the paper and deal with the possible rust issues? Either way I have clean-up issues, either the adhesive or the water on the CI.