I had a leak in my roof and now a water stain on my ceiling. My ceiling is not painted. Can I seal the stain with a primer and then cover it with thinned joint compound so it matches the color?
The affected drywall may be compromised. If it gets wet enough, the drywall under the paper loses it's integrity and expands a little. You could cut out the spot and put in new drywall, then tape and mud the edges. I never put joint compound over primer.