connecting drywall and plaster: joint compound over paint?
I’m replacing the cathedral ceiling in a stairwell. The walls are rock lathe plaster from the 50s. The ceiling is going to be drywall and plan is to use no-coat ultraflex 450 where they meet applied with all purpose drying joint compound.
The plaster walls are painted. Looks like the first coat was an enamel and then another 2 coats of latex paint. The last coat is probably not very good paint and applied pretty sloppily. I hit it with a heat gun and scraped a ~6″ stripe off at the top of the wall but there’s still some paint left on there, especially the first enamel layer.
Do i need to sand down to bare plaster for the compound to adhere reliably? Should I set the corner bead with durabond instead? Any flaws in the plan that i’m missing?
Thanks in advance.
Replies
You might want to use zinnser gardz before you apply the joint compound to make sure the old stuff is sealed really well. That stuff can work wonders on old problematic surfaces. I usually apply it, then do all of my taping and sanding and then apply an additional coat over the finished surface before painting.