painting stained walls

Hi,

Anyone know what I should do about the folowing?? I painted my Living- room walls, moldings, baseboards, all a pure, museum white. We had lots of rain and obviously a leak that made a bubble right under the ceiling molding + an ugly dark yellow stain (feels greasy) that driped down the wall. My husband thought it would be ok to paint OVER the stain........Now there is a "stain" where he painted right over the yellow stain: it looks almost gray and just shows itself on the wall.
I suggested priming the stain and THEN putting yet an other coat of paint on the entire wall so that it would not show up. Any suggestions? THANK YOU!!!!!!!!!

 

Stains will continue to bleed through paint unless you apply a couple coats of sealer. I prefer white shellac or B-I-N which is a shellac based sealer/primer.

 

I have had good results with Kilz. I used the oil based for the same problem in my son's room in our new-old house. I worked great, be sure to have a lot of ventilation though!