Patching and Plastering - Stain killer and wallpaper primer

I removed some old wallpaper, and there's a dark moldy area which I'm going to wash with a bleach solution. The primer that's there now seems to be latex - it will rub off on an alcohol-soaked cloth - and I plan on re-priming the walls with a latex wallpaper primer. Will the latex primer cover the moldy spot, or will I need to cover that with stain killer first? If so, what type of stain killer would work in this situation? Would it be oil or latex?

Can you remove all the mold? Unless all the mold is killed, it might come back. Primers aren't really formulated to stop mold growth. Solvent based paints/primers bond better and the chemical make up has the molecules closer together [which is why they are better stain hiders] so a solvent based primer might do a better job.

Since I scraped the remaining paste from the area, the mold is barely noticable. I also washed it with a bleach solution. But I will take your advice about covering it with stain killer.

So, you're saying that it's ok to put an oil based stain killer over the existing latex primer, and then latex primer over the stain killer?

Yes but you may not need the latex primer over the oil primer.

Thanks for the info, Marksr. And my walls thank you.Beer 4U2