I've noticed on a couple of small repair interventions, aluminum drywall corner L-bead does not hold mud as adhesively as drywall does, due to the texture/grip of aluminum. Is there a way to improve it by some kind of primer?
It's usually not a problem when the application mass is large so the less adhesive part around the bead is cohesive with a bigger one on drywall. But, when it doesn't have much drywall to piggyback on, it easily peels off or doesn't stay when applied.
