Oxalic acid can be used as a bleaching agent for both wood and stone. Wood, when exposed to the elements, can turn gray. When oxalic acid is applied on an old and graying wood floor, it brings back the wood floor’s natural white color. Actually, this acid is often used when preparing to stain old wood floors. It is also used by furniture manufacturers to lighten heavily stained areas of wood furniture in preparation for refinishing.
2. Removing Stains
Oxalic acid effectively removes ink, food stains, and many other types of stains. It is a gentle stain remover that eats the stain but leaves the base surfaces, such as wood, intact. You can use oxalic acid to remove most stains found on stone, brick, linoleum, wood, and vinyl surfaces. However, do not use oxalic acid if your flooring is sealed as it will eat through the finishing.
Although you can also use oxalic acid to remove stains from fabrics such as linen and cotton, it will take a lot of time, so it is better to have your fabrics dry cleaned instead.
3. Removing Rusts
Oxalic acid is also used to remove rusts that are commonly found on plumbing pipes and kitchen countertops, and is a major ingredient found in commercial rust removers for sinks, tubs, and metal rust stains.
4. Other Uses
Aside from bleaching, rust removing, and stain removing, oxalic acid is also used as a reducing agent in developing photographic film. You can also find it used in wastewater treatment as well since oxalic acid can effectively remove calcium from wastewater. And lastly, oxalic acid is also used as a grinding agent when polishing marble.