Rudder Trailing Edge Prep for Sealant

I'm closing up the rudder and need to adhere the wedge to the skin. I primed (Akzo two-part epoxy) the inside of the skin before I realized there is a specific instruction to leave the skin common to the wedge bare.

I've decided to use Proseal (AC-232-B2) as the adhesive. Should I sand all the primer away or can I get a good bond by just cleaning then roughing the surface with either ScotchBright or sandpaper?

If it's ok to bond over the primer, what cleaner should I use? Acetone? MEK? Soap and water only? IPA? I've heard that if you let whatever solvent evaporate it'll cause a real problem for bonding.

Anybody have any advice?

Vans recommends scoring the aluminum really good to create a bonding surface when building the tanks. I think this would apply here as well.

This isn't a critical bond. I'd lightly scuff the primer, wipe the dust off, and apply the proseal. The stuff sticks very well and, again, this is not a critical bond. You're only bonding the assembly to assist in creating a straighter trailing edge, so it only has to last until you're done riveting the trailing edge.

Both

I did boh ways on my RV9 trailing edge. What i found more important was to be
break the trailing edge skin; otherwise it came up on me and didnt sit completely flush to the wedge at the TE

I did this exact same thing on my rudder. The sealant here as far as I can tell is just to help keep the edge straight during riveting. I applied as normal and it came out straight as an arrow.