Treating mold or mildew on wood window sill

[Morganza]

The window sill was painted white and the cats and dogs have scratched it up. I decided to clean it up and repaint it. The old paint was peeling up so I scraped it all off down to the wood surface. The wood is in good condition, but in some areas there is a black stain in the wood that is too deep to sand off. I’m thinking about painting it with a bleach solution and let it dry before proceeding with some primer. My only concern here is that if I don’t get rid of the mold, it might interfere with the primer/paint adhesion. If it would not be a problem, I can easily just paint over it and move on. As you may be able to tell, I really don’t know what I’m doing, so some advice would be great.

Thanks,
Morgan

[FordMan59]

I had a severe water heater leak in 2016. (approximately $25,000 worth of damage according to estimates from a mold remediation company) I took care of the mold remediation/repairs myself. Here's what I used on the affected wood surfaces. https://www.concrobium.com/products/mold-control-spray/ I've been told this is nearly the same solution that Servco uses in mold remediation cases. This is also what a person who does mold remediation for a living told me to use. Most of the mold was underneath the sub flooring on the floor joists. I started out by washing the surface with a brush/soapy water and letting it dry, then I applied the Concrobium Mold Control to the surface using a spray bottle and letting it dry. Last I painted the joists with Kilz to seal the wood and keep the mold from coming back. I haven't seen or smelled any mold since. You could probably paint it with any paint product but, I'm sure you could paint it with Kilz, let it dry then paint it with any other paint product you want. The Kilz should cover the black stain and keep it from bleeding through your new paint. Be sure everything is good and dry before moving to the next step. In my case I let a dehumidifier run in the affected areas for about 2 weeks to remove the moisture from the wood and prevent rotting prior to sealing it and putting down new sub flooring. I researched this on the Internet and someone who does mold remediation gave me some tips/information. If this is mold you won't get all the stain out but you can kill the mold and keep it from returning.

[Morganza]

Thanks, that’s some very good info.

[FordMan59]

Here's a product that I wasn't aware of until tonight. https://www.concrobium.com/products/mold-stain-eraser/ I don't know whether it's an actual cleaner or whether it's a primer product. The Concrobium Mold Control is available at Home Depot but I don't remember seeing this product when I did my remediation/repairs. With my stains being pretty much confined to floor joist and not in visible areas I wouldn't have used this product anyway.