Mildew is formed by mould. It is an ugly, greyish to green fungus that grows on furniture, especially outdoor oak furniture that is prone to moisture. Mildew can ruin the appearance of oak furniture, and is hazardous to sensitive individuals with weakened immune systems. Allergic reactions from contact with mildew on furniture includes respiratory problems and rashes. It is easy to clean mildew from oak furniture, and restore the wood back to a natural state before mildew infestation.
Open all windows in work area if working inside. Spread old newspaper or tarps around the furniture on the floor. Put on plastic disposable gloves, and a dust mask. Take an electric sander and sand big pieces of furniture, like tables and dressers. Use 320 grit sandpaper to sand smaller pieces of furniture by hand. Use sandpaper to get into the hard to reach sections of decorative furniture. Remove wood dust with a tack cloth or clean paint brush.
Strip furniture with a chemical stripping agent. Use a house paint brush, and apply the chemical stripping agent to furniture in even strokes. Wait for the stripping agent to oxidise, and scrape at the surface of the furniture with a putty knife. Re-sand furniture after it is stripped with 150 grit sandpaper. Remove wood dust with a second clean tack cloth, or a clean paint brush.
Bleach oak wood to remove mildew. Transport furniture outside if weather permitting. Mix one cup of bleach to a half a bucket of warm water. Stir the bleach in the water with a stick. Put on protective gloves. Dip a strong bristled scrubbing brush into the bucket, and let it soak for a few minutes. Retrieve brush, and scrub furniture thoroughly. Repeat if necessary, letting the bleach soak for two hours into the surface of the mildew stains.
Fill a second clean bucket with warm water, and add two cap-fulls of mild liquid detergent to the water. Stir the detergent in the water with a stick until the water is soapy. Dip a clean scrubbing brush into the water, making sure to get plenty of soapy suds onto the furniture. Scrub furniture clean. Scrubbing with detergent will remove the excess bleach and help to deodorise the furniture. Remove soap with a garden hose. Let furniture air dry in the sun. Wait until furniture is completely dry before being transported back inside.
Finish furniture once it is dry with insect and waterproof polyurethane. The polyurethane will strengthen and seal wood furniture, protecting it from further mildew or mould growth. Stain or paint the wood first, if desired. Paint wood using latex based paint. Apply two coats with a clean paint brush. Let the first coat dry before painting a second coat. Apply one to three coats of stain with a clean paintbrush, until desired colour is achieved. Let dry in-between coats, then finish.