Older canvas oil paintings can sometimes need quite a bit of restoration. One of the main steps involved in most restoration processes involves finding and removing mold from the painting. The specific process you use depends on how much mold damage there is. However, if you are careful and use the right cleaning techniques, the mold can be removed and the painting restored.
Put the canvas oil painting in bright sunlight for several hours to dry up any moist mold.
Use a soft-bristled brush to carefully brush away the dried mold. A sawdust brush, for example, should not damage the canvas oil painting.
Fill a spray bottle with water and add several drops of household bleach. You don't need a lot to kill mold.
Mist the canvas oil painting where the mold was located. Also, mist the other side of the canvas right where the mold was on the opposite side.
Allow the canvas oil painting to dry completely. Place it back in the sun to speed up the drying process.