Dear Donia,
Can I save my mother's canvas oil paintings that are mildewed?
Q. Dear Donia,
A. Dear Linda,
I am sorry to hear that your mother's paintings have gotten smelly from mildew. It is not easy to remove the smell, but it can be done if you have a bit of patience. You have tried some methods that might work but need more time. Ozone is not good for paintings as it drastically increases the deterioration. Sunlight could work but does take time, and you should not expose the oil paint side to the sun but the back of the painting. his will allow the sunlight to get to the areas most likely affected by the mildew and prevent the colors from potentially fading. Only do this when the wind and relative humidity are low to prevent more problems.
You could also try getting some closet odor reducers that come in hanging bags and place one or two in a large garbage bag with the painting and let that go for a month or so and see how well it reduces the odor.
You can also try Microchamber paper available from Conservation Resources but if the paintings are large, this may not be a cost-effective method for you.
Reducing mildew odor takes time and patience and hopefully with at least the first two options, something you can try quickly and easily.
Good luck!